The Treatment of Hallux Valgus
Transcription
The Treatment of Hallux Valgus
www.pharexmedics.com Table of Contents biodegradable magnesium based screw in surgery Bunion Surgery-OrthoInfo – AAOS measurement and assessment of pain reduction new approach preoperative criteria and surgical outcome treatment of hallux valgus Windhagen et al. BioMedical Engineering OnLine 2013, 12:62 http://www.biomedical-engineering-online.com/content/12/1/62 RESEARCH Open Access Biodegradable magnesium-based screw clinically equivalent to titanium screw in hallux valgus surgery: short term results of the first prospective, randomized, controlled clinical pilot study Henning Windhagen1, Kerstin Radtke1, Andreas Weizbauer1, Julia Diekmann1, Yvonne Noll1, Ulrike Kreimeyer1, Robert Schavan2, Christina Stukenborg-Colsman1 and Hazibullah Waizy1* * Correspondence: [email protected] 1 Department of Orthopaedic Surgery, Hannover Medical School, Anna-von-Borries-Str.1-7, 30625 Hannover, Germany Full list of author information is available at the end of the article Abstract Purpose: Nondegradable steel-and titanium-based implants are commonly used in orthopedic surgery. Although they provide maximal stability, they are also associated with interference on imaging modalities, may induce stress shielding, and additional explantation procedures may be necessary. Alternatively, degradable polymer implants are mechanically weaker and induce foreign body reactions. Degradable magnesium-based stents are currently being investigated in clinical trials for use in cardiovascular medicine. The magnesium alloy MgYREZr demonstrates good biocompatibility and osteoconductive properties. The aim of this prospective, randomized, clinical pilot trial was to determine if magnesium-based MgYREZr screws are equivalent to standard titanium screws for fixation during chevron osteotomy in patients with a mild hallux valgus. Methods: Patients (n=26) were randomly assigned to undergo osteosynthesis using either titanium or degradable magnesium-based implants of the same design. The 6 month follow-up period included clinical, laboratory, and radiographic assessments. Results: No significant differences were found in terms of the American Orthopaedic Foot and Ankle Society (AOFAS) score for hallux, visual analog scale for pain assessment, or range of motion (ROM) of the first metatarsophalangeal joint (MTPJ). No foreign body reactions, osteolysis, or systemic inflammatory reactions were detected. The groups were not significantly different in terms of radiographic or laboratory results. Conclusion: The radiographic and clinical results of this prospective controlled study demonstrate that degradable magnesium-based screws are equivalent to titanium screws for the treatment of mild hallux valgus deformities. Keywords: Magnesium, Degradable, Hallux valgus, Osteosynthesis Introduction Currently, nondegradable implants are primarily made of steel or titanium. Although these implants provide maximum stability, these nondegradable materials interfere with imaging modalities, such as X-ray and magnetic resonance imaging, and often require an undesirable second operation to remove the implant [1,2]. Moreover, the mechanical properties of nondegradable implants (steel or titanium) are quite different © 2013 Windhagen et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Windhagen et al. BioMedical Engineering OnLine 2013, 12:62 http://www.biomedical-engineering-online.com/content/12/1/62 from those of cortical bone, potentially resulting in inhomogeneous stress transfer and limiting the bone-healing process [3,4]. This constellation of effects defines “stress shielding.” Therefore, it might be beneficial to use implants material with a Young’s modulus close to that of cortical bone. Currently, the most commonly used degradable implants are polymer-based. These are mechanically weaker than metallic devices and are associated with foreign body reactions and osteolysis [5]. However, the first magnesium-based implants used at the beginning of the 20th century exhibited high corrosion rates that consequently generated subcutaneous gas cavities and reduced mechanical stability [6]. Recently developed magnesium-based implants demonstrate improved anticorrosive and mechanical properties [1]. Degradable magnesium-based intravascular stents (WE43) yield good clinical results and are biocompatible [7]. The present study investigated the use of the MAGNEZIXW compression screw (Syntellix AG, Hannover, Germany). MAGNEZIXW is an aluminum-free magnesium alloy that is classified as an MgYREZr alloy according to DIN EN 1753. This alloy contains rare earth elements and is compositionally similar to WE43. It has already demonstrated good biocompatibility and osteoconductive quality in vivo [8]. The chevron osteotomy is a distal “V-shaped” metatarsal osteotomy that was first described by Austin and Leventen [9]. It is the operative option used to treat mild to moderate hallux valgus deformities. The angle of the “V” is about 60° and results in the impaction of the fragments without osteosynthesis. Recent studies have reported modification of the angulation and range of the limbs. The use of a greater angle and horizontal osteotomy can maximize the contact surface, but osteosynthesis would be necessary because fewer fragments would be impacted [10]. Loss of fixation and, consequently, malunions and pseudarthrosis, have been reported following surgery without fixation. Various studies have reported using K-wires, screws, staples, and plates [11]; however, screw fixation is mechanically superior to other modes of fixation [12]. The aim of this prospective, randomized clinical trial was to determine if the MgYREZr alloy-based screw (MAGNEZIXW) demonstrates equivalent clinical and radiographic outcomes to standard titanium screws in hallux valgus surgery. Material and methods Ethical approval This prospective, randomized controlled study (according to EN ISO 14155–1:2009 and EN ISO 14155–2:2009) was approved by the ethics committee of medical school hannover, monitored by an independent trial center, and conformed to the principles in the Declaration of Helsinki. All participating patients provided voluntary written informed consent. Implants The ends of the cannulated screws (shaft Ø, 2.0 mm; cannulation Ø, 1.3 mm) included two threads (Ø 3.0 and 4.0 mm) with different pitches in order to achieve interfragment compression [13]. The implants were made of a powdered metallurgically processed magnesium alloy: this aluminum-free material consists of MgYREZr (a material similar to WE43) that contains >90 wt% magnesium. With an average grain size of <5 μm, this high-performance alloy demonstrates an offset elastic limit of Rp0.2>250 MPa, tensile Page 2 of 10 Windhagen et al. BioMedical Engineering OnLine 2013, 12:62 http://www.biomedical-engineering-online.com/content/12/1/62 strength >275 MPa, and percent elongation at break >10%. Titanium screws with the same dimensions were used as the control (Figure 1). Study design Between March 2010 and July 2011, 26 patients (26 feet) with symptomatic hallux valgus were enrolled in this study (Table 1). The inclusion and exclusion criteria are shown in Table 2. Patients were randomly assigned by the independent trial center to either group before implantation without the knowledge of the medical investigators or surgeons. The study protocol included eight study visits (V1, preoperation; V2, operation; V3, 1–3 days postoperation; V4, 4–8 days postoperation; V5, 2 weeks postoperation; V6, 6 weeks postoperation; V7, 3 months postoperation; V8, 6 months postoperation). Clinical examinations were performed at V1 and V3–8 and included determination of the range of motion (ROM) of the first metatarsophalangeal joint (MTPJ), American Orthopaedic Foot and Ankle Society (AOFAS) score for hallux, pain level according to the visual analog scale (VAS), satisfaction rate (very satisfied, satisfied, or unsatisfied with the results), and identification of any complications. Laboratory analyses (also performed at V1 and V3–8) included determination of magnesium levels in the blood and urine, standard electrolytes (e.g., potassic, sodium, chloride, calcium, and phosphate), renal parameters (e.g., urea, creatinine, and creatinine clearance) and liver parameters (e.g., GOT, GPT, GammaGT, and alkaline phosphatase). Surgical technique A high tourniquet was placed at the thigh. Lateral release was performed over an incision that was placed between the first and second metatarsal bones. The musculus adductor hallucis tendon was released, and the lateral sesamoid was mobilized. The medial approach was performed according to the technique described by Waizy et al. [14]. The exostoses were removed, and the center of the metatarsal head was marked with a 1.2 mm K-wire. An oscillating saw was used to perform a 90° chevron osteotomy. Figure 1 The two cannulated screws with the same design. a) The titanium screw (Fracture compressing screw, Königsee Implantate GmbH, Am Sand 4, 07426 Allendorf, Germany), b) MAGNEZIXW Compression Screw (Syntellix AG Schiffgraben 11, 30159 Hannover, Germany). Page 3 of 10 Windhagen et al. BioMedical Engineering OnLine 2013, 12:62 http://www.biomedical-engineering-online.com/content/12/1/62 Page 4 of 10 Table 1 Demographic informations of the study groups Degradable implantgroup (DI) mean n SD Titan implantgroup (TI) mean SD 13 13 gender [w/m] 11/2 13/0 age [years] 57.2 7.2 49.9 16.5 weight [kg] 74.5 11.4 70.5 14.4 height [m] 1.68 7.0 1.68 9.1 BMI [kg/(m)2] 26.0 3.0 25.0 3.6 The distal fragment was displaced to the lateral side, and osteosynthesis was performed according to the patient group. Temporary fixation with a threaded K-wire (1.2 mm) was performed at the desired position of the screw. Intraoperative X-rays were acquired to verify correct K-wire positioning and determine screw length. A two-step pilot drillbit was used to make the countersunk hole in the head. In the titanium group (TI), the compression screw was turned to generate compression, and the K-wire was removed after the screw was positioned. In the degradable group (DI), additional predrilling was performed using a 2.0 mm diameter handoperated drill. The MgYREZr degradable compression screw was then inserted to generate compression, and the K-wire was removed after the screw was positioned. The overriding bone of the proximal metatarsal fragment was removed using an oscillating saw. The tourniquet was released, and the skin was sutured. Postoperative bandages were applied by holding the big toe in the correct position. Radiography All radiographs were conducted under standardized, weight-bearing conditions at V1, V3, and V6–8. Posterior-anterior radiographs were used to measure the hallux valgus angle (HVA), intermetatarsal angle (IMA), and the distal metatarsal articular angle (DMAA). To determine the axis of the first metatarsal bone, a line was drawn from the center of the head through the center of the base of the first metatarsal bone. This is considered the most precise, least biased method for determining Table 2 Inclusion and exclusion criteria of the study Inclusion Exclusion Symptomatic bunion with radiographic correlates Operations on the symptomatic foot in the past Patients aged 40-79 BMI> 32 Female fertile patients: obligate practice of two different secure contraceptive methods Pregnancy or lactation Normal function of the lower extremity Neurological pathologies Bone mineral density abnormalities (e.g. radiographic detected bone cysts in the first ray, manifested osteoporosis) Allergies against study products (components of the screws) Substitution of magnesia or manifested hepato-renal diseases with possibel resulting bone mineral density abnormalities Participation in other studies 30 days before the start of this study and during the participation in this study Windhagen et al. BioMedical Engineering OnLine 2013, 12:62 http://www.biomedical-engineering-online.com/content/12/1/62 postoperative effects [15]. All measurements were independently performed by three orthopedic surgeons. Postoperative treatment The postoperative treatment regimens were the same for both groups. Postoperative dressings were removed between the first and third postoperative days (V1–3). The big toe was held and stabilized in the correct position using hallux valgus wool and crepe bandages for 6 weeks, and the bandages were changed twice a week. Physiotherapy with only passive MTPJ mobilization was initiated after the removal of the first dressings. Sutures were removed 2 weeks after surgery (V5). For 6 weeks, full weight-bearing mobilization was allowed when wearing an orthotic shoe with a stiff sole. High-impact sports were allowed after 12 weeks. Statistics Significant differences in VAS and AOFAS scores for hallux were determined using t tests (IBM-SPSS version 20; Armonk, NY, USA). In this study, p<0.05 was considered statistically significant. Results This clinical study was performed between March 2010 and February 2012 without interruption. Follow-up examinations were performed on 12 patients per group. One patient in each group dropped out of the study after surgery for personal reasons. Complications did not occur in any patients during the follow-up period. Both groups demonstrated good to excellent results, including improvements in AOFAS score for hallux, and no significant differences were identified in any of the outcome measures (Figure 2). A total of 23 of 24 patients were very satisfied and indicated that they would undergo the same operation again. One patient in the DI group developed a superficial wound-healing problem and was unsatisfied. None of the patients developed a palpable gas cavity. VAS decreased in both groups (Figure 3). No significant differences were observed between visits. MTPJ stiffness was not observed. All patients demonstrated minimum passive ROM of 60° and minimum active ROM of 50° at the MTPJ. The mean (standard deviation) operation time was 40.0 (9.1) minutes for the DI group and 34.0 (3.3) minutes for the TI group. Figure 2 Preoperativ (V1) and postoperative AOFAS score for hallux. There is no significant difference between the improvement of the two groups (bars =mean value with standard deviation). Page 5 of 10 Windhagen et al. BioMedical Engineering OnLine 2013, 12:62 http://www.biomedical-engineering-online.com/content/12/1/62 Page 6 of 10 Figure 3 Preoperativ (V1) and postoperative VAS scores. There is no significant difference between the improvement of the two groups (bars = mean value with standard deviation). Chemical analysis revealed no significant elevations in blood magnesium levels. There were no significant differences between groups on the follow-up chemical or urine analyses. HVA, IMA, and DMAA improved in both groups (Table 3), and the pre- and postoperative radiographs are shown in Figure 4. The postoperative X-rays demonstrated no signs of avascular necrosis, no bone erosion due to the development of gas cavities, and no advanced arthritis in the MTPJ. The healing rate was 100%. None of the screws had to be removed during the study. Although 1 patient in the TI group developed a symptomatic screw head, she refused to have the screw removed during the 6 month followup period for personal reasons. The screw was removed 8 months after implantation. All adverse effects and complications were documented. General adverse events noted during this study included postoperative sickness (n=3, 2 DI and 1 TI patient) and pneumonia at 5 months after the operation (n=1 TI patient). Three superficial wound complications developed and demonstrated delayed wound healing (2 DI patients and 1 TI patient). Infections were ruled out by laboratory analysis and clinical inspection. All 3 wounds healed without revision. No allergic reactions or further systemic reactions were observed in either group. Complex regional pain syndrome (CRPS) and severe adverse effects were not observed. Discussion The chevron osteotomy has shown good to excellent clinical results in mild to moderate hallux valgus, with high patient satisfaction rates. Those results were mostly based Table 3 The IMA, HVA and DMAA preoperative and postoperative after 6 months Degradable implantgroup (DI) IMA HVA DMAA Titan implantgroup (TI) mean SD mean SD 12.88 1.82 12.58 1.44 6 months 7.67 2.89 6.04 2.49 Preop. 24.03 7.59 23.53 0.52 6 months 16.19 8.93 11.76 6.41 Preop. 11.01 5.05 12.91 6.96 6 month 7.28 4.07 5.43 2.64 Preop. Windhagen et al. BioMedical Engineering OnLine 2013, 12:62 http://www.biomedical-engineering-online.com/content/12/1/62 Figure 4 Preoperative radiographs (posterior-anterior) of a mild hallux valgus deformity. The correction is achieved by a chevron osteotomy. The postoperative radiographs show a bony healing in both groups. on Level 3–4 studies [16]. In this prospective randomized study concerning the screw, both groups showed good to excellent clinical and radiographic results with a high satisfaction rate. The equivalent clinical outcomes were considered a result of the operative procedure, and we did not detect any influence of the implant on the clinical features. The degradation of an implant can necessitate an undesirable second operative therapy for implant removal. Besides the additional cost, further problems may develop due to elevated infection risk associated with implant removal [17]. Also, up to 20% of patients develop new symptoms after a second surgery to remove the implant [18]. Coughlin reported that additional operative procedures for implant removal (screws, plates, pins) were necessary in 15% of patients with hallux valgus [19]. In the present study, no implant removals were necessary during the first 6 months after surgery. This may be attributable to the design of the screw, which lacked a prominent screw head. The implant removal rate due to soft tissue irritation was reported to be low with the head design of the Herbert screw [20]. However, because this study had a relatively short follow-up period and reduced irritation due to the screw head design, it was difficult to show the potential benefit of degradable screws given the reduction in redundant surgery. Degradable implants are currently in clinical use for fixation in chevron osteotomy. The clinical outcome is excellent for both degradable and nondegradable implants. Caminear et al. retrospectively studied a series of 18 chevron osteotomies fixed with copolymer pins and observed high AOFAS scores (87.4±14.9) and only one giant cell Page 7 of 10 Windhagen et al. BioMedical Engineering OnLine 2013, 12:62 http://www.biomedical-engineering-online.com/content/12/1/62 granuloma [21]. The AOFAS score for hallux is not validated; however, it is the most used clinical scoring system. Small et al. conducted a retrospective study of 71 chevron osteotomies fixed with degradable polymer pins and reported a 100% bone healing rate, but osteolysis appeared in 5.6% of cases [22]. The only previous comparative study (chevron osteotomy: polymer pins vs. permanent K-wires) was reported by Gill et al. [23]. No differences were found regarding the prevalence of clinical symptomatic complications, but osteolysis was observed in 10.2% of patients in the polymer-based group. In our study, 3 (2 DI and 1 TI) patients experienced delayed wound healing. Further studies with a greater number of patients are necessary to identify a possible clinical difference. Stable fixation with accelerated bone healing reduces immobilization time and the risk of developing joint stiffness. In contrast to polymer-based implants, magnesium alloys showed promising biomechanical results in vitro [24,25] and in vivo [26]. The in vivo results also attributed an osteoconductive quality to the magnesium alloy MgYREZr [8]. This would facilitate early bone healing, and consequently, faster mobilization with early recovery, which would potentially benefit the patients. Further studies should test this osteoconductive hypothesis by measuring bone healing velocity. The use of degradable magnesium implants is controversial. The degradation process produces hydrogen gas, and gas cavities have been described. The source of the gas cavities remains an issue of debate [27]. In clinical use, gas formation would be an obstacle to bone and wound healing. Waizy et al. performed a rabbit study with a 1 year follow-up to test the alloy MgYREZr and found no bone erosion due to gas cavities [8]. Corrosion occurs in both degradable and permanent implants. Implant wear may cause the accumulation of particles around implants that stimulate inflammation, osteoclast activation, and osteoblast inhabitation. This pathway induces osteolysis and may also trigger hypersensitivity and allergic reactions [28]. Witte et al. previously demonstrated that the magnesium alloy WE43 was nonallergenic in an epicutaneous patch test [29]. MgYREZr is similar to WE43; therefore, we hypothesized that it may also have a nonallergic composition. We did not observe any cases of allergic reaction during follow-up. The degradation of a magnesium alloy can potentially induce a systemic inflammatory reaction or pathologic changes in visceral organs. However, to date, no in vivo studies have reported either of those adverse events [30]. Waizy et al. postulated that MgYREZr would have good biocompatibility due to the absence of acute, subacute, and chronic systematic inflammatory reactions and the absence of specific pathologic changes in the visceral organs in an in vivo study [8]. The present clinical study confirmed the good clinical outcome hypothesized for this degradable magnesium alloy. The primary limitation of this study was the relatively short follow-up time, and future studies should be focused on long-term consequences. We set the endpoint of the study at 6 months follow-up because this was the typical endpoint for operative hallux valgus therapy at our institution. At 6 months, complete bone healing should be attained, and further radiographic controls should not be necessary. We were not able to verify complete screw degradation; however, based on in vivo results from Waizy et al., it is reasonable to assume that the magnesium alloy was completely or nearly completely degraded [8]. Another limitation of our study was the relatively low statistical power of the radiographic measurements. However, we could show an equivalent Page 8 of 10 Windhagen et al. BioMedical Engineering OnLine 2013, 12:62 http://www.biomedical-engineering-online.com/content/12/1/62 clinical outcome, and we did not observe pseudarthrosis or other implant-associated complications. The strength of this study is that it is the first prospective, randomized, single surgeon study to investigate a degradable, magnesium-based implant. Conclusion This pilot study demonstrated that the degradable magnesium-based screw was radiographically and clinically equivalent to the conventional titanium screw. We did not observe any instances of foreign body reaction, osteolysis, or systemic inflammatory reaction. Larger prospective randomized trials with a longer follow-up are needed to confirm the findings of this study. Abbreviations AOFAS: American Orthopaedic Foot and Ankle Society; DI: Degradable group; DMAA: Distal metartarsal angle; HVA: Hallux valgus angle; IMA: Intermetatarsal angle; MTPJ: Metatarsophalangeal joint; ROM: Range of motion; TI: Titanium group; VAS: Visual analog scale. Competing interests Mr. Robert Schavan is employed by the company Syntellix; he has not influenced the collection of data or its interpretation. The other authors have no competing interests. Authors’ contributions HW and CSC initiated the study and participated in its design and coordination. KR and UK collected and analyzed the data. AW and JD helped to draft the manuscript. YN coordinated the clinical study. RS participated in the design of the study and contributed the screw samples. HaW initiated and performed the study, analyzed the data, and wrote the manuscript. All authors read and approved the final manuscript. Acknowledgments We thank Nicole Lange for excellent technical support. This study was partially financed by Syntellix AG, Hannover, Germany. We acknowledge support provided by Deutsche Forschungsgemeinschaft (DFG). Author details 1 Department of Orthopaedic Surgery, Hannover Medical School, Anna-von-Borries-Str.1-7, 30625 Hannover, Germany. 2 Syntellix AG, Schiffgraben 11, 30159 Hannover, Germany. Received: 8 April 2013 Accepted: 25 June 2013 Published: 3 July 2013 References 1. Waizy H, Seitz JM, Reifenrath J, Weizbauer A, Bach FW, Meyer-Lindenberg A, Denkena B, Windhagen H: Biodegradable magnesium implants for orthopedic applications. J Mater Sci 2013, 48:39–50. 2. Sullivan PK, Smith JF, Rozzelle AA: Cranio-orbital reconstruction: safety and image quality of metallic implants on CT and MRI scanning. Plast Reconstr Surg 1994, 94:589–596. 3. Sumitomo N, Noritake K, Hattori T, Morikawa K, Niwa S, Sato K, Niinomi M: Experiment study on fracture fixation with low rigidity titanium alloy: plate fixation of tibia fracture model in rabbit. 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Submit your next manuscript to BioMed Central and take full advantage of: • Convenient online submission • Thorough peer review • No space constraints or color figure charges • Immediate publication on acceptance • Inclusion in PubMed, CAS, Scopus and Google Scholar • Research which is freely available for redistribution Submit your manuscript at www.biomedcentral.com/submit Page 10 of 10 1/27/2016 Bunion SurgeryOrthoInfo AAOS Bunion Surgery Most bunions can be treated without surgery. But when nonsurgical treatments are not enough, surgery can relieve your pain, correct any related foot deformity, and help you resume your normal activities. An orthopaedic surgeon can help you decide if surgery is the best option for you. Whether you've just begun exploring treatment for bunions or have already decided with your orthopaedic surgeon to have surgery, this booklet will help you understand more about this valuable procedure. What Is A Bunion? A bunion is one problem that can develop due to hallux valgus, a foot deformity. The term "hallux valgus" is Latin and means a turning outward (valgus) of the big toe (hallux). The bone which joins the big toe, the first metatarsal, becomes prominent on the inner border of the foot. This bump is the bunion and is made up of bone and soft tissue. What Causes Bunions? http://orthoinfo.aaos.org/topic.cfm?topic=A00140 1/8 1/27/2016 Bunion SurgeryOrthoInfo AAOS By far the most common cause of bunions is the prolonged wearing of poorly fitting shoes, usually shoes with a narrow, pointed toe box that squeezes the toes into an unnatural position. Bunions also may be caused by arthritis or polio. Heredity often plays a role in bunion formation. But these causes account for only a small percentage of bunions. A study by the American Orthopaedic Foot and Ankle Society found that 88 percent of women in the U.S. wear shoes that are too small and 55 percent have bunions. Not surprisingly, bunions are nine times more common in women than men. Can Bunions Be Prevented? Bunions often become painful if they are allowed to progress. But not all bunions progress. Many bunion problems can be managed without surgery. In general, bunions that are not painful do not need surgical correction. For this reason, orthopaedic surgeons do not recommend "preventive" surgery for bunions that do not hurt; with proper preventive care, they may never become a problem. Bunion pain can be successfully managed in the vast majority of cases by switching to shoes that fit properly and don't compress the toes. Your orthopaedic surgeon can give you more information about proper shoe fit and the types of shoes that would be best for you. Follow these general points of shoe fit: http://orthoinfo.aaos.org/topic.cfm?topic=A00140 2/8 1/27/2016 Bunion SurgeryOrthoInfo AAOS Do not select shoes by the size marked inside the shoe. Sizes vary among shoe brands and styles. Judge the shoe by how it fits on your foot. Select a shoe that conforms as nearly as possible to the shape of your foot. Have your feet measured regularly. The size of your feet change as you grow older. Have both feet measured. Most people have one foot larger than the other. Fit to the largest foot. Fit at the end of the day when your feet are the largest. Stand during the fitting process and check that there is adequate space (3/8" to 1/2") for your longest toe at the end of each shoe. Make sure the ball of your foot fits well into the widest part (ball pocket) of the shoe. Do not purchase shoes that feel too tight, expecting them to "stretch" to fit. Your heel should fit comfortably in the shoe with a minimum amount of slippage. Walk in the shoe to make sure it fits and feels right. (Fashionable shoes can be comfortable.) Some shoes can be modified by stretching the areas that put pressure on your toes. Splints to reposition the big toe and orthotics (special shoe inserts shaped to your feet) also may relieve pain. For bunions caused by arthritis, medications can be prescribed to reduce pain and swelling. Is Bunion Surgery For You? If nonsurgical treatment fails, you may want to consider surgery. Many studies have found that 85 to 90 percent of patients who undergo bunion surgery are satisfied with the results. Reasons that you may benefit from bunion surgery commonly include: Severe foot pain that limits your everyday activities, including walking and wearing reasonable shoes. You may find it hard to walk more than a few blocks (even in athletic shoes) without significant pain. Chronic big toe inflammation and swelling that doesn't improve with rest or medications. Toe deformitya drifting in of your big toe toward the small toes. Toe stiffnessinability to bend and straighten your toe. Failure to obtain pain relief from nonsteroidal antiinflammatory drugs. Their effectiveness in controlling toe pain varies greatly from person to person. Failure to substantially improve with other treatments such as a change in shoes and antiinflammatory medication. http://orthoinfo.aaos.org/topic.cfm?topic=A00140 3/8 1/27/2016 Bunion SurgeryOrthoInfo AAOS As you explore bunion surgery, be aware that socalled "simple" or "minimal" surgical procedures are often inadequate "quick fixes" that can do more harm than good. And beware of unrealistic claims that surgery can give you a "perfect" foot. The goal of surgery is to relieve as much pain, and correct as much deformity as is realistically possible. It is not meant to be cosmetic. Types of Bunion Surgery Orthopaedic surgeons use many different surgical procedures to treat bunions. The common goal of these procedures is to realign the joint, relieve pain, and correct deformity. These procedures include: Repair of the Tendons and Ligaments Around the Big Toe These tissues may be too tight on one side and too loose on the other, creating an imbalance that causes the big toe to drift toward the others. Often combined with an osteotomy, this procedure shortens the loose tissues and lengthens the tight ones. Arthrodesis Removal of the damaged joint surfaces, followed by the insertion of screws, wires, or plates to hold the surfaces together until it heals. Used for patients with severe bunions, severe arthritis, and when other procedures have failed. Exostectomy Removal of the bump on the toe joint; used only for an enlargement of the bone with no drifting of the big toe. This procedure is seldom used because it rarely corrects the cause of the bunion. Resection Arthroplasty Removal of the damaged portion of the joint, used mainly for patients who are older, have had previous bunion surgery, or have severe arthritis. This creates a flexible "scar" joint. http://orthoinfo.aaos.org/topic.cfm?topic=A00140 4/8 1/27/2016 Bunion SurgeryOrthoInfo AAOS Osteotomy The surgical cutting and realignment of the joint. Your orthopaedic surgeon will choose the procedure best suited to your condition. The Orthopaedic Evaluation If you are interested in exploring bunion surgery, your family physician can refer you to an orthopaedic surgeon for an evaluation. The orthopaedic evaluation consists of three components: A medical history, in which your orthopaedic surgeon gathers information about your general health and asks you about the extent of your pain and ability to find shoes that don't hurt. He or she also will ask you about other medical conditions that could affect your surgical outcome. Diabetes and rheumatoid arthritis, for example, can increase the risk of infection and interfere with proper healing. Circulatory problems can increase postoperative pain and impede healing as well. A physical examination to assess the extent of the misalignment and soft tissue damage and to check for the presence of other foot deformities, such as hammertoes and corns. Xrays to determine the extent of damage and deformity in your toe joint. Your orthopaedic surgeon will review the results of your evaluation with you and discuss whether surgery would be the best method to relieve your pain and deformity. Nonsurgical options, including switching to different shoes, also will be discussed. Your orthopaedic surgeon also will explain the potential risks and complications of bunion surgery at this time. Realistic Expectations About Bunion Surgery http://orthoinfo.aaos.org/topic.cfm?topic=A00140 5/8 1/27/2016 Bunion SurgeryOrthoInfo AAOS An important factor in deciding whether to have bunion surgery is understanding what the procedure can and can not do. The vast majority of patients who undergo bunion surgery experience a dramatic reduction of foot pain after surgery, along with a significant improvement in the alignment of their big toe. Bunion surgery will not allow you to wear a smaller shoe size or narrowpointed shoes. In fact, you will have some shoe restrictions for the rest of your life. Always follow the recommendations for shoe fit presented in this booklet. Remember that the main cause of the bunion deformity is a tight fitting shoe. If you return to that type of shoe wear, your bunion will reappear. Preparing for Surgery If you decide to have bunion surgery, you may be asked to have a complete physical with your family physician before surgery to assess your health. If you have heart or lung conditions or other chronic illnesses, you will need a preoperative medical clearance from your family physician. Before surgery, tell your orthopaedic surgeon about the medications you are taking. He or she will tell you which medications you should and should not stop taking before surgery. Tests, including blood samples, a cardiogram, a chest Xray, a urine sample, and special foot Xrays, may be ordered by your orthopaedic surgeon to help him or her plan your procedure. Your Surgery Almost all bunion surgery is done on an outpatient basis. You will most likely be asked to arrive at the hospital or surgical center one or two hours prior to surgery. After admission, you will be evaluated by a member of the anesthesia team. Most bunion surgery is performed under ankle block anesthesia, in which your foot is numb, but you are awake. General or spinal anesthesia is used occasionally. The anesthesiologist will stay with you throughout the procedure to administer other medications, if necessary, and to make sure you are comfortable. The surgery takes about one hour. Afterwards, you will be moved to the recovery room. You will be ready to go home in one or two hours. Possible Complications After Surgery Fewer than 10 percent of patients experience complications from bunion surgery. Possible complications can include infection, recurrence of the bunion, nerve damage, and continued pain. If complications occur, they are treatable but may affect the extent of your full recovery. Your orthopaedic surgeon will explain various options in treating these complications. Your Recovery at Home The success of your surgery will depend in large part on how well you follow your orthopaedic surgeon's instructions at home during the first few weeks after surgery. You will see your surgeon regularly for the next several months to make sure your foot heals properly. http://orthoinfo.aaos.org/topic.cfm?topic=A00140 6/8 1/27/2016 Bunion SurgeryOrthoInfo AAOS Dressing Care You will be discharged from the hospital with bandages holding your toe in its corrected position. You also will wear a special postoperative surgical shoe or cast to protect your foot. Your sutures will be removed about two weeks after surgery, but your foot will require continued support from dressings or a brace for six to eight weeks. To ensure proper healing, it is very important not to disturb your dressings and to keep them dry. Interference with proper healing could cause a recurrence of the bunion. Be sure to place a plastic bag over your foot while showering. Bearing Weight Your orthopaedic surgeon may advise you to use a walker, cane, or crutches for the first few days after surgery. You can gradually put more weight on your foot as your wound heals. However, walk only short distances during the first few weeks following surgery. You will probably be able to drive again within about a week. Swelling and Shoe Wear Keep your foot elevated as much as possible for the first few days after surgery, and apply ice as recommended by your orthopaedic surgeon to relieve swelling and pain. You will have some swelling in your foot for about six months. After your dressings have been removed, wear only athletic shoes or soft leather oxford type shoes for the first several months until the surgery has completely healed. Do not wear fashion shoes, including high heels, until after six months. Follow the tips on shoe fit presented earlier in this booklet when selecting your shoes. This will help prevent the recurrence of your bunion. Exercises to Strengthen Your Foot Some exercises or physical therapy may be recommended to restore your foot's strength and range of motion after your surgery. Your surgeon may recommend exercises using a surgical band to strengthen your ankle or marbles to restore motion in your toes. Always start these exercises slowly and follow your surgeon's or physical therapist's instructions regarding repetitions. Medication Your orthopaedic surgeon may prescribe antibiotics to prevent infection for several days after your surgery. Pain medication to relieve surgical discomfort also will be prescribed for several days. Avoiding Problems After Surgery http://orthoinfo.aaos.org/topic.cfm?topic=A00140 7/8 1/27/2016 Bunion SurgeryOrthoInfo AAOS Though uncommon, complications can occur following bunion surgery. Contact your orthopaedic surgeon if: Your dressing loosens, comes off or gets wet. Your dressing is moistened with blood or drainage. You develop side effects from postoperative medications. Also, call your orthopaedic surgeon immediately if you notice any of the following warning signs of infection: Fever. Chills. Persistent warmth or redness around the dressing. Increased or persistent pain. Significant swelling in the calf above the treated foot. Your orthopaedic surgeon is a medical doctor with extensive training in the diagnosis and nonsurgical and surgical treatment of the musculoskeletal system, including bones, joints, ligaments, tendons, muscles, and nerves. This brochure has been prepared by the American Academy of Orthopaedic Surgeons and is intended to contain current information on the subject from recognized authorities. However, it does not represent official policy of the Academy and its text should not be construed as excluding other acceptable viewpoints. Persons with questions about a medical condition should consult a physician who is informed about the condition and the various modes of treatment available. Last reviewed: September 2012 CoDeveloped by the American Orthopaedic Foot and Ankle Society AAOS does not endorse any treatments, procedures, products, or physicians referenced herein. This information is provided as an educational service and is not intended to serve as medical advice. Anyone seeking specific orthopaedic advice or assistance should consult his or her orthopaedic surgeon, or locate one in your area through the AAOS "Find an Orthopaedist" program on this website. Copyright 2012 American Academy of Orthopaedic Surgeons Related Links OrthoInfo The American Academy of Orthopaedic Surgeons 9400 West Higgins Road Rosemont, IL 60018 Phone: 847.823.7186 Email: [email protected] http://orthoinfo.aaos.org/topic.cfm?topic=A00140 8/8 Nake et al. Journal of Foot and Ankle Research 2014, 7(Suppl 2):A6 http://www.jfootankleres.com/content/7/S2/A6 JOURNAL OF FOOT AND ANKLE RESEARCH MEETING ABSTRACT Open Access Measurement and assessment of pain reduction six months following combined scarf akin’s osteotomies +/- 2/3 toe correction for hallux valgus Irvine Nake1*, Derek Santos2, Gary Boon3, Francis Babi1, David Cartwright4, Anthony Maher5, Lee Murphy6, Tosin Adekunle1, Martin Murgatroyd3, Sally Plant1, Jackie Ludlam1, Mavis Clark1 From The College of Podiatry Annual Conference 2013: meeting abstracts Liverpool, UK. 14-16 November 2013 Background Hallux valgus deformity is not a single disorder as the name might imply, but a complex multifactorial deformity of the first ray that is often accompanied by deformity and symptoms of pain even in the lesser toes. Research into foot pain has been limited by the lack of a clear understanding as a whole as to what constitutes foot problems. The aim of this study was to measure the effects of the combined Scarf and Akin’s osteotomy with or without 2/3 toe correction for Hallux valgus deformity at 6 months period. Outcome measures used were the pain scale (VAS) and the Manchester-Oxford Foot Questionnaire (MOXFQ). Methods The study was a prospective design and included 30 patients aged 18 to 65+ years with painful bunions plus or minus lesser toe involvement with foot deformity in the study who went on to be treated by the above mentioned surgical procedure with normal heel postoperative weightbearing in a stiff soled surgical shoe during a 6 months period. Mean age of patients at the time of surgery was 59 years, 25 patients were female and 4 were male. History and physical pre-operative assessments (clinical and radiographic) including outcome measures (VAS & MOXFQ) results were performed both at baseline and at 6 months. Post-operative management of the patients was as per normal guidelines set by the department of Podiatric Surgery following a reconstructive bunion surgery. 1 Department of Podiatric Surgery, Doncaster & Bassetlaw Hospitals NHS Foundation Trust, Doncaster, South Yorkshire, UK Full list of author information is available at the end of the article Results The patient related outcome measures, VAS and the MOXFQ questionnaire for the cohort clearly showed statistical significances following foot surgery. The VAS pain scale domain, the median based on the post-surgical scores, was reduced to 0 (IQR 0) with a score change of -6 (IQR 3) (P<0.001). The MOXFQ pain domain, the median based on the post-surgical scores, was reduced to 5 (IQR 0) with a score change of -55 (IQR 27) (P<0.001). The MOXFQ walking and standing domain, the median based on the post-surgical scores was reduced to 0 (IQR 15) with a score change of -50 (IQR 28) (P<0.001). The MOXFQ social interaction domain, the median based on the post-surgical scores, was reduced to 0 (IQR 7) with a score change of -50 (IQR 25) (P<0.001). No post-operative complications were observed, only one patient was lost to post op follow up and her data was discarded. Conclusion A combined Scarf Akin osteotomy with or without 2/3 toe is an effective procedure for the correction of symptomatic Hallux valgus foot deformity at 6 months. It permits early weight bearing of the treated extremity and it requires exact pre-operative planning and strict adherence to the operative technique if pain is to be effectively eliminated and the HRQOL restored with above satisfactory results. Authors’ details 1 Department of Podiatric Surgery, Doncaster & Bassetlaw Hospitals NHS Foundation Trust, Doncaster, South Yorkshire, UK. 2Department of Podiatric Medicine, Faculty of Health Sciences, Queen Margaret University, Musselburgh, Scotland, UK. 3Department of Podiatric Surgery, Rotherham © 2014 Nake et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http:// creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Nake et al. Journal of Foot and Ankle Research 2014, 7(Suppl 2):A6 http://www.jfootankleres.com/content/7/S2/A6 Page 2 of 2 NHS Foundation Trust, Rotherham, UK. 4Podiatric Surgery Unit, Derbyshire Community Health Services NHS Trust, Buxton, UK. 5Department of Podiatric Surgery, Nottinghamshire Healthcare NHS Trust, Nottingham, UK. 6 Department of Podiatric Surgery, Norfolk Community Health and Care NHS Trust, Norwich, UK. Published: 14 November 2014 doi:10.1186/1757-1146-7-S2-A6 Cite this article as: Nake et al.: Measurement and assessment of pain reduction six months following combined scarf akin’s osteotomies +/- 2/3 toe correction for hallux valgus. Journal of Foot and Ankle Research 2014 7(Suppl 2):A6. Submit your next manuscript to BioMed Central and take full advantage of: • Convenient online submission • Thorough peer review • No space constraints or color figure charges • Immediate publication on acceptance • Inclusion in PubMed, CAS, Scopus and Google Scholar • Research which is freely available for redistribution Submit your manuscript at www.biomedcentral.com/submit Send Orders for Reprints to [email protected] The Open Orthopaedics Journal, 2014, 8, 361-367 361 Open Access Modified Wilson’s Osteotomy for Hallux Valgus Deformity. A New Approach Konstantinos C. Xarchas*, Dimitrios Mavrolias and Georgios Kyriakopoulos 1st Department of Orthopedics and Trauma, General Hospital G. Gennimatas, Athens, Greece Abstract: We introduce a new set of modifications and present the results from 48 patients (a total of 60 feet operated), who underwent this modified Wilson’s osteotomy for the correction of Hallux Valgus. Patients were of an average age of 52 years old (from 21 to 75 years of age) and were followed up for a mean of 12 months post-operatively. Patient evaluation was made with the symptom scoring system as presented by Kataraglis et al., with the final outcome being satisfactory in all of the cases. This set of modifications introduced to the original Wilson’s osteotomy, proved to offer a stable, predictable and satisfactory outcome in all cases and we strongly recommend it. Keywords: Hallux valgus, modifications, Wilson’s osteotomy. INTRODUCTION Hallux Valgus represents a rather common deformity and a variety of operative procedures has been developed for its treatment [1]. Osteotomies of the first metatarsal have played a prominent role in the surgical management of hallux valgus deformities. Distal metatarsal osteotomies are usually preferred, together with remodeling of the medial exostosis and some form of soft tissue restoration and balancing technique. Wilson, in 1963, described an oblique osteotomy. His technique presented a simple and relatively stable way of displacing the metatarsal head, without the need for internal fixation. The broad osteotomy surfaces had reduced risk of nonunion, and the large metatarsal head fragment minimized the chances of avascular necrosis. The technique consists of an oblique osteotomy of the distal third of the first metatarsal, combined with remodeling of the medial exostosis. The line of the osteotomy starts on the medial side at the proximal end of the exostosis, extending laterally at an angle of 45°. The distal fragment is thus transferred and the remaining prominent shaft is removed after the osteotomy is in its correct alignment [2, 3]. Ever since, there have been a number of proposed modifications to the initial [4]. Helal et al. in 1974, changed the direction of the osteotomy by tilting it from a dorsaldistal position to plantar-proximal [5]. In 1976, Davis and Litman used Wilson's technique without the removal of the medial exostosis, which allowed the first metatarsophalangeal joint to remain undisturbed [6]. Allen et al. also introduced modifications in 1981, mainly using a cancellous screw for rigid internal fixation [7]. Pittman and Burns, in 1984, altered the direction of the osteotomy from a proximalmedial to distal-lateral, to address hallux limitus by plantarly displacing the capital fragment [8]. The Telfer osteotomy for *Address correspondence to these authors at the 1st Department of Orthopedics and Trauma, General Hospital G. Gennimatas, Athens, Greece; Tel/Fax: 00302107768507; E-mail: [email protected] 1874-3250/14 hallux valgus was introduced in 1985. It included modifications to the original Wilson’s oblique osteotomy at the neck of the first metatarsal head that produce a maximum lateral displacement of the distal fragment and retain the ideal position by means of rigid internal fixation [9]. In 1988, Klareskov et al. modified Wilson's osteotomy by plantar-flexing the first metatarsal head as it is shifted laterally. The plantar displacement of the distal fragment allows the first metatarsal to bear more of the weight-bearing forces, thus reducing excessive pressure on the lateral metatarsal heads [10]. Finally, some authors obviated the need for plaster cast immobilization even when using various types of internal fixation of the osteotomy [11-13]. In this paper we present the results from 48 patients who underwent Wilson’s osteotomy for hallux valgus with a set of concomitant modifications to the original technique. PATIENTS AND METHODS A number of 48 patients (a total of 60 feet), forty two women and six men, were retrospectively evaluated. All of them underwent the proposed modified Wilson’s osteotomy for Hallux Valgus deformity, from 1999 till 2011. Thirty six of the patients were operated on one foot and twelve bilaterally. Their mean age at the time of operation was 52 years old (ages varying from 21 to 75 years of age). All patients were followed-up for a mean of 12 months. Their main reason for the operation was regional pain (40% of the patients), inability to wear shoes (30%) and cosmetic reasons (30%). The prior to operation mean time of pain and disability varied from 4 to 50 years (on average 16 years). Preoperatively all patients were carefully examined for the possibility of osteoarthritis of the MTP joint (hallux rigidus) and if this was present a different type of operation was offered to them. It must be noted that patients which required extensive corrections of the forefoot were not included in the study group. Concomitant operations were limited to extensor tenotomies and/or arthrodesis of the 1st interphalangeal joint of lesser toes. 2014 Bentham Open 362 The Open Orthopaedics Journal, 2014, Volume 8 Surgical Technique All of the surgical operations were performed by the same surgeon, under general or regional (spinal) anesthesia and with the concomitant use of a pneumatic tourniquet. The steps of the operation were as follows: A medial longitudinal skin section centered over the first metatarsophalangeal joint (Figs. 1, 2) was followed by a “Y”-shaped capsular incision and exostectomy (Fig. 3). Oblique osteotomy angled from Xarchas et al. medially-distal to laterally-proximal, starting from the proximal end (base) of the exostectomy and additionally with a plantar inclination of 30º. It should be noted here that the osteotomy was performed with the use of a power saw, only. On the contrary, the exostectomy was always performed with the use of an osteotomy chisel (Figs. 4, 5). We consider that mishaps such as fracture of the metatarsal shaft or removal of excessive amount of bone from the metatarsal head can this way be avoided. The distal fragment was stabilized with the use of a K-wire inserted through the margin of the articular surface of the head of the metatarsal, with respect to the joint surface and advanced either intramedullarly in the shaft, or transfixing it. Next, trimming of the protruding bony edge of the proximal fragment with the use of a bone nibbler was performed and “Y-V” capsulorraphy with the use of interrupted absorbable sutures. Skin suturing and bandaging. The foot was kept elevated for 48 hours, after which heel weight-bearing was initiated. Skin sutures where removed after the second post-operative week and the K-wires were removed at approximately four weeks after surgery. Full weight bearing was routinely allowed on the sixth postoperative week. The patients were followed up both radiologically and clinically at six weeks (Figs. 6, 7), three months, six months and one year. Fig. (1). X-rays of the feet (AP): bilateral hallux valgus. Fig. (2). Skin incision. Fig. (4). Positioning of saw for osteotomy. Note proximal and plantar direction. Fig. (3). Capsular flap elevated, exostectomy performed. Fig. (5). Reduction of osteotomy for stabilization with k-wire. Modified Wilson’s Osteotomy for Hallux Valgus Deformity The Open Orthopaedics Journal, 2014, Volume 8 363 were examined for passive and active range of motion of the first metatarsophalangeal joint as well as for the presence of callosities under the head of any of the metatarsals. (a) Fig. (6). Postoperative X-rays (AP). Radiology There are 60 full sets of x-rays, both pre- and postoperative. On a regular basis anteroposterior (frontal) xrays of the foot under stress (weight bearing) were performed, in order to calculate the Hallux Valgus Angle (angle between the axis of the first metatarsal and the axis of the proximal phalanx) and the First Intermetatarsal Angle (angle between the axis of the first and the second metatarsal) [14]. The same views were used to estimate the shortening of the first metatarsal after correcting the magnification factor, as was proposed and described by Zlotoff [15]. Review of Patients All patients were reviewed by the same reviewer. Generally speaking, there have been proposed the AOFAS Hallux, MTP and IP scoring system [16,17] proposed by AAOS, the lower extremity functional scale (LEFS) and the scoring system used by Broughton and Winson presented with minor modifications by D. Kataraglis et al. [18] to evaluate patients pre- and post-operatively. In our study we used the scoring system of D. Kataraglis (Table 1), preferred for its simplicity to be completed accurately by all patients, and in addition we assessed the radiologic findings by measuring the above mentioned post-surgically achieved angles. Excellent were considered the results of patients who achieved Grade 1 in all categories, good were considered the results of patients who achieved no more than two Grade 2 and no Grade 3 scores and poor were considered all the rest of the results. As far as the angles are concerned we collected and wrote the data to assess early relapse or overcorrection complications. In the same time all patients Table 1. (b) Fig. (7). (a, b) Postoperative X-rays (Lat). Note that proximal fragment slightly covers distal, to prevent it from dorsal displacement. Symptom score (according to D. Kataraglis et al.). Grade 1 Grade 2 Grade 3 Cosmetic Appearance Happy Slight Reservation Unhappy Pain in first MTP joint None Occasional On normal activities Metatarsalgia None After> 3h walking/standing After<3h walking/standing Function/Activities No restrictions Slight Restriction Severe restriction in daily activities Shoes used Any Slight restriction Difficulty in finding/only special shoes 364 The Open Orthopaedics Journal, 2014, Volume 8 Limitations of the Study Our study presents limitations. The included number of patients is relatively small, but the exclusion criteria used were followed very strictly, with emphasis given on proper x-rays and complete x-ray series. Many patients were thus excluded. No comparative method was used as the authors’ intention was only to present objective and accurately measured results from this method. Still, the results obtained may hopefully be considered for future comparative studies. The follow-up time of the patients can be considered short. The measurements however, proved to be rather stable when reevaluated after one year. On the counter-part, all the results, as mentioned again, were calculated and recorded by the same reviewer-author, which adds to the reliability of the presented values. RESULTS Of the sixty feet, fifty two were graded as 1 and eight as 2. Complications such as osteonecrosis of the metatarsal head or non-union of the osteotomy were not observed. There was no dorsal displacement of the distal part of the osteotomy. In 28 feet, surgery for the lesser toes was also required, usually by means of extensor tenotomy or arthrodesis of the first interphalangeal joint due to hammer toe deformity. Shortening of the first toe was occasionally mentioned by the patients but this, generally, was not of major importance. Shortening of the second toe after arthrodesis of the PIP in cases of hammer toe deformity, always improved the cosmetic appearance of the foot. Skin necrosis around the surgical wound was met in four cases and was treated successfully non-operatively in all circumstances. All four patients had not complied with postoperative orders for foot elevation and skin necrosis was considered the result of excessive swelling. Residual swelling often persisted for up to three months but gradually disappeared with activity. The mean correction HVA angle achieved was 14.8º with a range between 10º and 25º and a mean correction of IMA was 7º ranging from 12º to 4º The radiologic findings remained rather stable throughout the follow-up (Table 2). DISCUSSION As a clinical entity, hallux valgus is a disorder of the forefoot for the correction of which numerous techniques have been proposed. The rational indicates that no single technique can be used to address all the degrees and complex deformities of the forefoot, this opinion represents the opinion of the writers, too. As so, modifications to basic techniques have been proposed by various authors, which address the weak points of each technique and can be used to increase the effective range of deformities they can correct. The proposed set of modifications is the result of study and experience. Most of them are being used or have been proposed as parts of other techniques but haven’t been performed as a combined set with Wilson’s osteotomy. Wilson’s osteotomy has been selected as the base technique, because of its ease to perform. It has a relatively predictable post-operative behavior and has been well studied [19, 20]. As a nature it can be used effectively to correct 25-40 degrees of Hallux Valgus Angle and 12-16 degrees of First Intermetatarsal Angle. It is a broad osteotomy, requiring little stabilization, although it is inherently unstable. It is Xarchas et al. oblique thus has a reduced risk of nonunion, and retains a large distal fragment thus providing a low risk of avascular necrosis. Our proposed modifications address the weak points of Wilson’s initially proposed technique. The incision runs medially in the internervous plane and provides good exposure of the bunion and capsule and good aesthetic result. The plantar tilting of the osteotomy provides an even larger contact surface for the osteotomy and prevents the distal fragment from displacing dorsally, which resulted in “sticking toe” deformity [21] and also increases the weight bearing forces received, decreasing this way the strain on the rest of the heads of the metatarsals in a similar sense as proposed by Klareskov et al. [22]. The stabilization via kwire both addresses the inherent instability of the osteotomy and reduces the excessive shortening of the metatarsal which is a common cause of metatarsalgia especially of the 2nd metatarsal [20]. The “Y-V” capsulotomy and capsuloplasty, allows for “fine” adjustment of the corrections and further increases the stability of the area. These modifications resulted in a relative stability post-operatively which did not necessitate plaster, or other means of stabilization [23]. Thus, patients initiated heel weight bearing as soon as pain allowed (encouraged to do so from the 2nd post-operative day), resuming simple daily activities fairly quickly. The selection of an appropriate technique for the treatment of forefoot malformations related with hallux valgus has been a topic of debate with mid-shaft osteotomies, e.g. Scarf, gaining many supporters, mainly due to the increased range of HVA and IMA it can address. It is generally accepted that it is very technically demanding, with a long learning curve, and difficult to treat complications. Its results remain comparable to the simpler Chevron osteotomy for the same range of angles [24]. Also the results of proximal Chevron osteotomy over distal, have been comparable, but the risk of avascular necrosis on a long term remains to be determined [25]. A comparative study between unmodified Wilson’s osteotomy and Mitchell’s osteotomy [26], concluded that shortening was more frequent with Wilson’s osteotomy, thus adding to the known opinion that more than 10mm shortening is usually poorly tolerated and is associated with future metatarsalgia [27], but that is the main weak point of Wilson’s. This is one of the main reasons the writers of this articles consider very important the stabilization of the osteotomy. CONCLUSION Hallux valgus deformity is a very frequently encountered clinical entity in orthopedic practice. A vast number of surgical techniques have been proposed to correct the deformity and indications have been proposed for the selection of the appropriate technique according to each case. Special anatomic plates and power tools have been introduced and surgical skill requirements have vastly increased in time. Wilson’s osteotomy with the proposed modifications is a technically straightforward approach, requiring minimum and easily accessible surgical tools and materials and has provided predictable and well accepted results in our practice. We consider it gives a foothold, even for young orthopaedists, to address a good range of hallux valgus deformity patients and we strongly recommend it. Modified Wilson’s Osteotomy for Hallux Valgus Deformity Table 2. Pat. The Open Orthopaedics Journal, 2014, Volume 8 365 Results. Sympt. Score, Sympt. Score, Sympt. Score, HVA Correction, HVA Correction, IMA Correction, Other Shortening Complications 3 Month 6 Month 12 Month Post Op 12 Months 12 Months Operations 1 I I I 20 19 10 8mm Arthrodesis - 2 II II II 22 17 12 9mm Arthrodesis - 3 I I I 19 17 11 8mm Tenotomy - 4 I I I 12 12 6 5mm - - 5 I I I 17 16 10 7mm Arthrodesis - 6 I I I 12 12 5 3mm - - 7a I II II 14 14 7 5mm - - 7b I II II 20 18 11 8mm - Skin Necr. 8 I I I 14 13 7 6mm Arthrodesis - 9 I I I 15 14 6 5mm - - 10 I I I 17 16 9 7mm Arthrodesis - 11 I I I 13 13 7 5mm - - 12 I I I 18 17 8 7mm Tenotomy - 13 I I I 14 14 6 5mm - - 14a II II II 24 20 12 9mm Arthrodesis - 14b I I I 12 12 6 4mm - - 15 I I I 21 19 10 8mm Arthrodesis Skin Necr. 16 I I I 16 16 8 7mm Arthrodesis - 17 I I I 11 11 6 4mm - - 18 I I I 15 13 7 6mm Tenotomy - 19 I II II 17 16 10 7mm Arthrodesis - 20a I I I 15 13 7 5mm - - 20b I I I 14 14 6 4mm - - 21 I I I 11 11 6 4mm - - 22 I I I 24 21 10 8mm - - 23a I I I 11 10 6 5mm - Skin Necr. 23b II II II 24 19 10 9mm Arthrodesis - 24 I I I 14 12 6 5mm Tenotomy - 25a I I I 18 16 9 7mm Arthrodesis - 25b I I I 15 14 7 6mm Tenotomy - 26 I I I 17 17 8 7mm - - 27 I I I 16 15 6 6mm - - 28 I I I 18 18 8 7mm Arthrodesis - 29 I II II 16 13 7 6mm Arthrodesis - 30 I I I 10 10 4 4mm - - 31a I I I 13 12 6 6mm Tenotomy - 31b I I I 12 12 6 5mm - - 32a I I I 20 19 10 8mm - - 32b I I I 14 14 6 5mm - - 33a I I I 15 14 7 6mm Arthrodesis - 33b I I I 15 15 6 6mm Arthrodesis - 366 The Open Orthopaedics Journal, 2014, Volume 8 Xarchas et al. (Table 2) contd….. Pat. Sympt. Score, Sympt. Score, Sympt. Score, HVA Correction, HVA Correction, IMA Correction, Other Shortening Complications 3 Month 6 Month 12 Month Post Op 12 Months 12 Months Operations 34 I I I 14 13 6 5mm Arthrodesis - 35 I I I 11 11 5 4mm - - 36a I I I 10 10 4 5mm - - 36b I I I 13 12 7 6mm Tenotomy - 37 I I I 12 12 6 5mm - - 38a I I I 13 12 6 5mm Tenotomy - 38b I I I 14 14 7 6mm - - 39 II II II 25 18 11 9mm Arthrodesis Skin Necr. 40 I I I 11 10 5 4mm - - 41a I I I 10 8 4 3mm - - 42b I I I 13 12 6 5mm - - 43 I I I 14 13 8 6mm Tenotomy - 44 I I I 11 11 5 4mm - - 45 I I I 12 11 4 4mm - - 46a I I I 14 14 7 6mm Tenotomy - 46b I I I 12 11 6 4mm - - 47 I I I 11 10 5 4mm - - 48 I I I 17 16 8 7mm Tenotomy - (HVA and IMA values are presented in degrees and represent [preoperative value – postoperative value]). CONFLICT INTEREST [12] The authors confirm that this article content has no conflict of interest. [13] ACKNOWLEDGEMENTS [14] Declared none. REFERENCES [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] Coughlin MJ. Hallux valgus. J Bone Joint Surg 1996; 78-A: 93266. Wilson JN. Oblique displacement osteotomy for hallux valgus. J Bone Joint Surg Br 1963; 45B: 552-6. Booley BJ, Berryman DB. Wilson's osteotomy of the first metatarsal for hallux valgus in the adolescent and the young adult. Aust NZ J Surg 1973; 43: 255-61. White DL. Variations of the Wilson bunionectomy. Clin Pediatr Med Surg 1991; 8(1): 95-110. Helal B, Gupta SK, Gojaseni P. Surgery for adolescent hallux valgus. Acta Orthop Scand 1974; 45: 271-95. Davis M, Litman T. Simple osteotomy for hallux valgus. Minn Med 1976; 12: 836-8. Allen TR, Gross M, Miller J, Lowe LW, Hutton WC. The assessment of adolescent hallux valgus before and after first metatarsal osteotomy. Int Orthop 1981; 5: 111-5. Pittman SR, Burns DE. The Wilson bunion procedure modified for improved clinical results. J Foot Surg 1984; 23: 314-20. Farguharson-Roberts MA, Osborne AH. The Telfer osteotomy for hallux valgus. J R Navy Med Serv 1985; 71: 15-8. Klareskov B, Dalsgaard S, Gebuhr P. Wilson shaft osteotomy for hallux valgus. Acta Orthop Scand 1988; 59: 307-9. Geldwert JJ, McGrath M, Rock GC, Mancuso JE. Wilson bunionectomy with internal fixation: a ten-year experience. J Foot Surg 1991; 30: 574-9. [15] [16] [17] [18] [19] [20] [21] [22] [23] [24] Ramanathan EBS, Heywood-Wadington MB. Plaster support after Wilson’s osteotomy for hallux valgus. J Bone Joint Surg 1988; 70B: 412-4. Shereff MJ, Sobel MA, Kummer FJ. The stability of fixation of first metatarsal osteotomies. Foot Ankle 1991; 11: 208-11. Smith R, Reynolds CJ, Stewart MJ. Hallux valgus assessment: Report of research committee of American Orthopaedic Foot and Ankle Society. Foot Ankle 1984; 5: 92-103. Zlotoff H. Shortening of the first metatarsal following osteotomy and its clinical significance. J Am Podiatr Assoc 1977; 67: 412-26. Kitaoka HB, Alexander IJ, Adelaar RS, Nunley JA, Myerson MS, Sanders M. Clinical rating systems for the ankle-hindfoot, midfoot, hallux and lesser toes. Foot Ankle Int1994; 15 (7): 349-53. Kitaoka HB, Patzer GL. Analysis of clinical grading scales for the foot and ankle. Foot Ankle Int 1997; 18: 443-6. Kataraglis D, Dinley RJ, Kapetanos G. Etude comparative des ostéotomies de Mitchell et de Wilson dans le traitement de l’hallux valgus. Acta Orthop Bel 2001; 67(2): 149-56. Schemitsch E, Horne G. Wilson’s osteotomy for the treatment of hallux valgus. Clin Orthop 1989; 240: 221-5. Givissis P, Karataglis D, Christodoulou A, Terzidis I, Pournaras J. Wilson osteotomy stabilised by means of internal fixation for the treatment of hallux valgus. Acta Orthop Belg 2004; 70(1): 57-63. Helal B, Gupta SK, Gojaseni P. Surgery for adolescent hallux valgus. Acta Orthop Scand 1974; 45: 271. Klareskov B, Dalsgaard S, Gebuhr P. Wilson shaft osteotomy for hallux valgus. Acta Orthop Scand 1988; 59(3): 307-9. Ramanathan EBS, Heywood-Waddington MB. Plaster support after Wilson’s osteotomy, for hallux valgus. J Bone Joint Surg Br 1988; 70(3): 412-4. Deenik AR, Pilot P, Brandt SE, van Mameren H, Geesink RG, Draijer WF. Scarf versus chevron osteotomy in hallux valgus: a randomized controlled trial in 96 patients. Foot Ankle Int 2007; 28(5): 537-41. Modified Wilson’s Osteotomy for Hallux Valgus Deformity [25] [26] The Open Orthopaedics Journal, 2014, Volume 8 Park CH, Jang JH, Lee SH, Lee WC. A Comparison of proximal and distal chevron osteotomy for the correction of moderate hallux valgus deformity. Bone Joint J 2013; 95-B(5): 649-56. Madjarevic M, Kolundzic R, Matek D, Smigovec I, Crnkovic T, Trkulja V. Mitchell and Wilson metatarsal osteotomies for the Received: February 3, 2014 [27] 367 treatment of hallux valgus: comparison of outcomes two decades after the surgery. Foot Ankle Int 2006; 27(11): 877-82. D. Karataglis D, Dinley RJ, Kapetanos G. Comparative study between Wilson and Mitchell metatarsal osteotomies for the treatment of Hallux Valgus in adults. Acta Orthop Belg 2001; 67(2): 149-56. Revised: September 15, 2014 Accepted: September 17, 2014 © Xarchas et al.; Licensee Bentham Open. This is an open access article licensed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited. Hallux valgus Preoperative criteria and surgical outcome Axel Deenik The printing of this thesis was financially supported by: Researchfonds Bronovo Anna Foundation Nederlandse Orthopaedische Vereniging Mathys Medical Photography: Axel Deenik Painting: High heel damaging the skeleton of the forefoot is painted by René Boelen. Black and white photograph of original colour painting, which can be viewed at consultation room of Axel Deenik. This image may not be published or reproduced without permission of René Boelen. The copyright of articles that have been published has been transferred to the concerning journals. Production & print: Datawyse / Universitaire Pers Maastricht ISBN 978 95 6159 411 2 © Copyright Axel Deenik, Maastricht 2015 No part of this thesis may be published or reproduced without permission of the author Hallux valgus Preoperative criteria and surgical outcome PROEFSCHRIFT ter verkrijging van de graad van doctor aan de Universiteit Maastricht, op gezag van de Rector Magnificus, Prof. dr. L.L.G. Soete volgens het besluit van het College van Decanen, in het openbaar te verdedigen op donderdag 5 maart 2015 om 14.00 uur door Axel R. Deenik P UM UNIVERSITAIRE PERS MAASTRICHT Promotor Prof. dr. R.A. de Bie Copromotores Dr. J.W. Louwerens Dr. A.D. Verburg Beoordelingscommissie Prof. dr. L.W. van Rhijn, voorzitter Prof. dr. S.K. Bulstra Prof. dr. R.G.H.H. Nelissen Dr. J.M. Sieben Prof. dr. J.A.M.C.F. Verbunt Contents Chapter 1 General introduction and aims 7 Chapter 2 Hohmann osteotomy in hallux valgus: The influence of the intermetatarsal angle in a 5 year follow-up study 17 Chapter 3 Scarf versus chevron osteotomy in hallux valgus: a randomized controlled trial in 96 patients. 25 Chapter 4 Equivalent correction in scarf and chevron osteotomy in moderate and severe hallux valgus: a randomized controlled trial. 35 Chapter 5 Hallux valgus angle as main predictor for correction of hallux valgus. 47 Chapter 6 Evidence of treatment algorithms for hallux valgus. 57 Chapter 7 Validity of hallux valgus angle measurement using plantar pressure measurement: A pilot study. 69 Chapter 8 General discussion 77 Chapter 9 Summary Samenvatting (Summary in Dutch) 87 89 Valorization 91 Dankwoord 99 Curriculum vitae 105 CHAPTER 1 General introduction 7 INTRODUCTION Prosperity can prompt human beings to show off their personal success. China had a highly developed culture during the T’ang dynasty, around our ninth century. The upper class had the custom of binding the feet of their eldest daughters to prevent growth. These Lotus feet (figure 1 and 2) were considered highly attractive. Their limited function was not an issue, since it was assumed these privileged children would never need to work. Figure 1 Lotus foot Figure 2 Lotus shoes In today’s society high-heels may be considered equally ambivalent. Half of British women feel more confident when wearing high heels at work, and a quarter feel more assertive and acknowledged by others, as revealed in a British survey. On the other hand, it has long been recognized that high heels cause complaints. Dr. Martha M. Bacon, Associate Professor of Physical Education, was quoted as saying in 1921 (following a 16-year study of high heels and health) “Headaches, rheumatism, nervousness, and various other troubles, including irritability of temper will disappear when women cease to wear the deforming French heel and the growing child is shod with broad shoes”.2 However, these claims are not supported in current literature. High-heel shoes with a narrow shoebox can be seen as the major extrinsic factor in development of hallux valgus,9 a deformity of the foot with a bump on the inside of the foot with angulation of the great toe. The possible impact of a one-inch heel can be illustrated by a 22 percent increase in pressure on the forefoot and a three-inch heel causes an increase of 76 percent. This pressure increases even further with a narrow toe box, which can compromise forefoot function. However, in spite of the influence of highheels, hallux valgus is in fact a multi-factorial condition. Intrinsic factors contribute to hallux valgus as well; genetic predisposition was found in 90 percent of the patients.17 Different foot deformities such as hindfoot pronation and Achilles contracture are also associated with hallux valgus.5 9 CHAPTER 1 Hallux valgus starts with cosmetic changes, but it might gradually lead to a painful biomechanically compromised foot. People with disabling foot pain risk a decrease in mobility and have an increased risk of falling.10 Severe hallux valgus with forefoot insufficiency can have a serious impact on quality of life. A meta-analysis has estimated the percentage of hallux valgus in adults at 23% (and 35.7% in elderly people aged over 65 years).16 Therefore, treatment is not just of cosmetic importance. Figure 3a Footcandy? A shoe-store, with Jimmy Choo on display Figure 3b Advertisement to commercialize foot surgery ‘Foot Facelift’ Because of the possible impact of hallux valgus, treatment is an important issue. Hallux valgus cannot be reversed by splints or orthotics.7 Correction surgery might be needed to decrease pain and correct the function of the foot. The opposite occurs in ‘cosmetic foot clinics’ in which surgery is advertised to fit into fashionable shoes (fig 3), concern about this subject was raised in the New York Times in an article entitled: ‘If shoe won’t fit, fix the foot?’ The magnitude in this subject can be illustrated with a search on Google ‘cosmetic foot surgery’ led to 7,280,000 results (August 2013). Cosmetic surgical procedures are not performed by orthopaedic surgeons and might decrease function of the foot. The popularity of these clinics might be explained because orthopaedic surgeons tend to combine their surgical therapy with high-heel restrictions instead of fashionable shoe advice. Furthermore, the current level of orthopaedic surgery leaves a void for commercial foot surgery. Recently, increasing efforts have been made to improve the correction power in hallux valgus surgery.21 The underlying biomechanical and anatomical mechanisms should be understood in order to improve outcome. Anatomically, the bump on the medial side of the foot starts with varus displacement of the first metatarsal bone, and concurrently the big toe deviates, angulates and pronates (figure 4). The first metatarsal head is vulnerable to extrinsic forces, because muscles do 10 INTRODUCTION not insert on the first metatarsal head. The first metatarsal bone is stabilized within the longitudinal direction of the tendons that insert on the phalanx. When the medial metatarsal bone starts shifting to medial, the dorsomedial insertion of the abductor hallucis shifts plantair, which causes a lower opposing force of the adductor hallucis. Because of the medial shift of the first metatarsal, changes occur in the first tarsometatarsal joint. Figure 4 a and b. Different stages of hallux valgus The biomechanical consequence of the medial shift of the metatarsal head is that the muscles enforce more lateral to the center of rotation, which leads to progression of the deformity. Because the deviation of the phalanx, it works as a fulcrum on the first metatarsal bone. A biomechanical study of Sanders showed that the medial deviation of the metatarsal head is a result of flexion forces.19 The effect is a widening of the forefoot. Less weight is transferred to the first ray and the pressure is transferred to the second and third ray of the forefoot. A first ray deformity can further extend, which may result in callus formation and pain. Hallux valgus might lead to a sequence of anatomical changes that go together with biomechanical deterioration. Preferably, these changes should be reversed with treatment and lead to biomechanical restoration. Conservative treatment can be effective in pain relief. In mild deformity adaptation of the shoes can be sufficient to reduce pressure of the bunion. When shoe adaptation is not sufficient, foot-orthotics may resolve symptoms. Although conservative measures can be effective to ameliorate symptoms, these orthotics do not cure nor prevent evolu11 CHAPTER 1 tion of mild or moderate hallux valgus.18 When conservative therapy fails, corrective surgery should be considered. Surgical correction is a superior treatment modality for hallux valgus in comparison to orthoses.20 The historical development of surgical treatment starts in the 19th century. The understanding of hallux valgus resembled the current patients’ view, that it was purely an enlargement of the soft tissue, first metatarsal head, or both, most commonly caused by ill-fitting footwear. Thus, treatment concentrated on removal of the overlying bursa sometimes in combination with the bony prominence of the medial head, exostosectomy, which had varying results. In 1881 Reverdin changed this point of view by describing hallux valgus as a deforming pathology and presented the first osteotomy to address the deformity. In this procedure the metatarsal bone was corrected by resection of a wedge shaped piece of bone from the first metatarsal and lateralizing the distal fragment. This operation is considered to be the first type of operation that aims to correct hallux valgus by means of osteotomy. Subsequently, more than 140 surgical procedures have been developed and combined for correction surgery of hallux valgus. The plethora of surgical procedures show there is no perfect one; all have their specific advantages and shortcomings. In order to improve outcome, understanding of the aspects that define hallux valgus is necessary. Preferably, the earlier mentioned biomechanical criteria should be reversed in correction surgery. We have no data to link the biomechanical changes to corresponding surgical procedures. However, hallux valgus is defined according to clinical features and different angles measured on radiographs. The following factors used in preoperative planning of hallux valgus have been identified and categorized. The hallux valgus angle is the angle between the bone of the first metatarsal and proximal phalanx. This angle shows the magnitude of the deformation and is used to grade severity.1 The intermetatarsal angle is the angle between the bone of the first and second metatarsal. Metatarsus primus varus is defined by high intermetatarsal angle, and is more frequently seen in patients with hallux valgus in contrast to a normal control group.11 The distal metatarsal articular angle is the angle between the articular surface and the diaphysis of the first metatarsal. This angle is difficult to measure due to high interand intraobserver variability; however, it should be considered in preoperative planning. Metatarsophalangeal joint (MTPJ): The joint between the first metatarsal bone and the hallux. The absence of arthritis or degenerative changes in the metatatarsophalangeal joint (MTPJ) is important to the decision whether the joint can be preserved. However, even in the absence of radiographic arthritis, cartilage lesions were found in the MTPJ in patients with hallux valgus. The grade of cartilage lesion was correlated with hallux valgus angle (figure 5).3 12 INTRODUCTION Figure 5 Radiograph of hallux valgus foot Hypermobility of the first tarsometatarsal joint is a clinical finding. In many reports increased mobility of the TMT joint has been proposed as a causative factor in hallux valgus development.15,12 Others dispute the significance of TMT hypermobility.5 Only the Klaue device can measure TMT mobility reliably, however, this is clinically difficult to apply.12 The preoperative factors mentioned above are used to distinguish different types of hallux valgus; hallux valgus severity, first metatarsophalangeal (MTP) congruency and tarsometatarsal (TMT) hypermobility. These types should be corrected with specific surgical procedures and are organised in flow-charts. Data to support these schemes are often based on level III evidence or derived from historical perspective. We have performed a retrospective study of Hohmann osteotomy in which we found that the outcome declined with increasing IMA. This finding corresponded with the predictive value of intermetatarsal angle and limitation of distal osteotomy.6 Some biomechanical influences are not included in schemes, which may necessitate a change in the surgical strategy. These include severe pes planus, Achilles tendon contracture, rupture of the posterior tibial tendon, neuromuscular disorders and rheumatoid arthritis. Treatment of hallux valgus essentially consists of correction of the bony deformity (figure 6 and 7) and soft-tissue imbalances. The bony deformation is caused by subluxation of the first metatarsal. The lack of muscle inserts on the first metatarsal head entail that its position cannot be stabilised directly, stabilisation occurs indirectly within the longitudinal tendons. 13 CHAPTER 1 Figure 6 Model of the first and second ray of the foot with hallux valgus Figure 7 Different model after osteotomy of the first metatarsal bone In cadaver studies of soft-tissue elements of hallux valgus, reduction of TMT hypermobility was found after correction of hallux valgus.4 Based on anatomic dissections of adductor hallucis, transverse and oblique heads, first metatarsophalangeal lateral capsule and suspensory ligament, the actual extent of the release may be inconsistent and unpredictable.13 In cadaver sessions in hallux valgus feet, we have tried to quantify the contributions of these structures to the soft-tissue contracture. From dorsal to ventral we dissected to the plantar plate. In dissection of these cadaver feet, we were not able to find a model to reduce the deformity to a single soft-tissue structure. These cadaver studies and algorithms have been developed to improve outcome. The majority of surgical procedures deal with bony correction. These surgical procedures include proximal and distal osteotomies, fusion of the metatarsophalangeal or tarsometatarsal joint and soft-tissue procedures. Each procedure has its specific advantages, learning curve and pitfalls. In research articles often one surgical procedure is studied without defining the type of hallux valgus. However, there might be a discrepancy between the theoretical advantage of different procedures for matching types of hallux valgus and a practical solution to use one or a limited number of procedures. 14 INTRODUCTION Although good results are found in different studies, in other reports patient dissatisfaction remains high. A Cochrane review concluded that quality of studies remains poor.8 There has been a trend toward higher levels of evidence in foot and ankle surgery literature over a decade, but the differences of different surgical procedures did not reach significance.22 Because a hallux valgus deformity can progress, and this potentially can influence mobility at older age, improvement of hallux valgus surgery is not just of cosmetic importance.14 Improvement of hallux valgus surgery can be achieved within following subheadings: criteria for preoperative planning, outcome in comparison to hallux valgus severity and outcome of different surgical procedures. The goal is to categorize existing evidence for treatment-protocols of hallux valgus with studies focusing on the different preoperative criteria in relation to the outcome of specific procedures. In Chapter 2 the influence of the intermetatarsal angle is studied in Hohmann osteotomy, and the outcome of distal procedure is plotted against the intermetatarsal angle. In Chapter 3 the chevron and scarf osteotomies are compared in a randomized controlled trial. Specific interest concerns radiographic outcome of shaft versus distal osteotomy. In Chapter 4 the scarf and chevron osteotomies are divided in subgroups according to IMA, and the outcome of both procedures are compared within subgroups. Chapter 5 studies the influence of different preoperative radiographic parameters. A regression analysis is performed to test the influence of these parameters on outcome. Chapter 6 presents a systematic review of preoperative parameters and surgical procedures. Evidence for preoperative parameters that can influence outcome is studied. Evidence for possible advantages of surgical procedures is discussed. In Chapter 7 the validity of a calculated hallux valgus angle, derived from plantar pressure measurements is tested. This angle, measured from electronic pressure measurements EMED, is compared to radiographic measured hallux valgus angle. Chapter 8 discusses the methods, results and possible implications of our studies. 15 CHAPTER 1 References 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 16 Antrobus, J. N.: The primary deformity in hallux valgus and metatarsus primus varus. Clin Orthop Relat Res, (184): 251-5, 1984. Bacon, D. M. M.: High heels, injurious to health. The Sydney Morning Herald 7, 1921. Bock, P.; Kristen, K. H.; Kroner, A.; and Engel, A.: Hallux valgus and cartilage degeneration in the first metatarsophalangeal joint. J Bone Joint Surg Br, 86(5): 669-73, 2004. Coughlin, M. J.; Jones, C. P.; Viladot, R.; Glano, P.; Grebing, B. R.; Kennedy, M. J.; Shurnas, P. S.; and Alvarez, F.: Hallux valgus and first ray mobility: a cadaveric study. Foot Ankle Int, 25(8): 537-44, 2004. Coughlin, M. J., and Shurnas, P. S.: Hallux valgus in men. Part II: First ray mobility after bunionectomy and factors associated with hallux valgus deformity. Foot Ankle Int, 24(1): 73-8, 2003. Deenik, A. R., and Albers, G. H. R.: De invloed van de intermetatarsale hoek op de resultaten van de Hohmann osteotomie bij hallux valgus - een 5-jaars follow-up. NTvO, 6: 9-12, 1999. Ferrari, J.: Bunions. Clin Evid (Online), 2009. Ferrari, J.; Higgins, J. P.; and Prior, T. D.: Interventions for treating hallux valgus (abductovalgus) and bunions. Cochrane Database Syst Rev, (1): CD000964, 2004. Kato, T., and Watanabe, S.: The etiology of hallux valgus in Japan. Clin Orthop Relat Res, (157): 78-81, 1981. Keenan, A. M.; Tennant, A.; Fear, J.; Emery, P.; and Conaghan, P. G.: Impact of multiple joint problems on daily living tasks in people in the community over age fifty-five. Arthritis Rheum, 55(5): 757-64, 2006. Kilmartin, T. E.; Barrington, R. L.; and Wallace, W. A.: Metatarsus primus varus. A statistical study. J Bone Joint Surg Br, 73(6): 937-40, 1991. Klaue, K.; Hansen, S. T.; and Masquelet, A. C.: Clinical, quantitative assessment of first tarsometatarsal mobility in the sagittal plane and its relation to hallux valgus deformity. Foot Ankle Int, 15(1): 9-13, 1994. Lin, I.; Bonar, S. K.; Anderson, R. B.; and Davis, W. H.: Distal soft tissue release using direct and indirect approaches: an anatomic study. Foot Ankle Int, 17(8): 458-63, 1996. Menz, H. B.; Morris, M. E.; and Lord, S. R.: Foot and ankle risk factors for falls in older people: a prospective study. J Gerontol A Biol Sci Med Sci, 61(8): 866-70, 2006. Myerson, M. S., and Badekas, A.: Hypermobility of the first ray. Foot Ankle Clin, 5(3): 469-84, 2000. Nix, S. E.; Vicenzino, B. T.; Collins, N. J.; and Smith, M. D.: Characteristics of foot structure and footwear associated with hallux valgus: a systematic review. Osteoarthritis Cartilage, 20(10): 1059-74, 2012. Pique-Vidal, C.; Sole, M. T.; and Antich, J.: Hallux valgus inheritance: pedigree research in 350 patients with bunion deformity. J Foot Ankle Surg, 46(3): 149-54, 2007. Reina, M.; Lafuente, G.; and Munuera, P. V.: Effect of custom-made foot orthoses in female hallux valgus after one-year follow up. Prosthet Orthot Int, 37(2): 113-9, 2013. Sanders, A. P.; Snijders, C. J.; and van Linge, B.: Medial deviation of the first metatarsal head as a result of flexion forces in hallux valgus. Foot Ankle, 13(9): 515-22, 1992. Torkki, M.; Malmivaara, A.; Seitsalo, S.; Hoikka, V.; Laippala, P.; and Paavolainen, P.: Surgery vs orthosis vs watchful waiting for hallux valgus: a randomized controlled trial. Jama, 285(19): 2474-80, 2001. Wagner, E., and Ortiz, C.: Osteotomy considerations in hallux valgus treatment: improving the correction power. Foot Ankle Clin, 17(3): 481-98, 2012. Zaidi, R.; Abbassian, A.; Cro, S.; Guha, A.; Cullen, N.; Singh, D.; and Goldberg, A.: Levels of evidence in foot and ankle surgery literature: progress from 2000 to 2010? J Bone Joint Surg Am, 94(15): e1121-10, 2012. CHAPTER 2 Hohmann osteotomy in hallux valgus: The influence of the intermetatarsal angle in a 5 year follow-up study Translation from: Hohmann osteotomieën bij hallux valgus; de invloed van de intermetatarsale hoek in een studie met een follow-up van 5 jaar. N.T.v.O. vol.6 1999: 9-12 Axel Deenik, Rob Albers 17 CHAPTER 2 Abstract We investigated 21 patients (24 feet) with hallux valgus after performing a Hohmann osteotomy and compared the long-term results of feet with metatarsus primus varus (MPV) with those with normal intermetatarsal (IMT) angles. The average angle of hallux valgus in 9 toes with normal IMT angle was 25 degrees, and was corrected to 15 degrees. The average angle of hallux valgus in 13 toes with MPV was 35 degrees and was corrected to 17 degrees. The clinical and radiological results of patients with MPV were worse than in the group with normal IMT angles. In both groups one patient required revision surgery. Hohmann osteotomy is a reliable procedure for patients with a normal IMT angle. MPV seems a bad prognostic factor for correcting hallux valgus. For patients with hallux valgus and MPV proximal osteotomies should be considered. 18 HOHMANN OSTEOTOMY Introduction Many procedures for correcting hallux valgus have been described. The Hohmann osteotomy is a common procedure on the continent, and relatively rare described.4 Helal reported instability as a disadvantage of the Hohmann osteotomy, therefore authors have used a T-plate in order to achieve a rigid fixation.1 Most procedures report a success rate between 77 and 95 percent.2,4 There seems to be no surgical procedure that covers the complete pathological range of hallux valgus. We believe metatarsus primus varus is an important aspect in the preoperative planning of hallux valgus. In reports MPV is defined from IMT angles from 9 degrees.6 Correction problems in hallux valgus seem to arise from higher IMT angles, particularly subcapital osteotomies seem to correct moderate to severe MPV insufficiently. Meier found in Chevron and Mitchell osteotomies worse results in patients with IMT angles exceeding 12 degrees, compared to patients with normal IMT angles.4 Mann recommends to use subcapital osteotomies only in patients with hallux valgus with IMT angles below 15 degrees.5 Meyerson describes for a modified Lapidus procedure to use an IMT angle of at least 16 degrees.8 The objective of this study is to determine the result of the Hohmann osteotomy in moderate to severe metatarsus primus varus compared with normal intermetatarsal angles. Patients and methods 31 toes in 28 consecutive patients with hallux valgus were operated with a Hohmann osteotomy from 1989 till 1992. Indication was hallux valgus and a painful bunion. Three patients were excluded from the follow-up because preoperative X-rays were missing, 4 patients could not be reached. In a retrospective study 24 feet in 21 patients were clinically examined, standing AP and lateral X-rays were taken, figure 1, and a questionnaire was applied according to the Bonney and MacNab classification, see table 1.1 The subjective and objective items were equally important for the overall score. There were 18 females and 3 males. The average age at operation was 37 years, with a range from 12 to 52 years. The mean follow-up period was 5 years, with a range between 3.5 and 7.5 years after operation. One patient had a previous unsuccessful Wilson osteotomy. The hallux valgus angle is the angle formed by the longitudinal axes of the first metatarsal and the proximal phalanx. The intermetatarsal angle is the angle formed by the line drawn to the centre of the first metatarsal head to the first metatarsal base and the 19 CHAPTER 2 longitudinal axis of the second metatarsal. The IMT and hallux valgus angles were measured on the preoperative X-rays, and the X-rays taken by follow-up. Preoperative IMT angles exceeding 13 degrees were considered as metatarsus primus varus. There was no significant age difference between both groups. Patients that required revision surgery after the Hohmann osteotomy were classified as poor. Operative technique Operation is performed with use of a tourniquet. Incision is made over the medial aspect of the first metatarsophalangeal joint. The abductor hallucis longus is identified. Subcapitally a small medial based wedge is excised with an oscillating saw. Following the metatarsal head is lateralized for one third of the metatarsal width. The metatarsal is head is transfixed at the metatarsal shaft using a small T plate and screws. The medial capsule and the abductor hallucis are reefed. The surgical procedures were performed by orthopaedic surgeons and residents. Figure 1 a and b Case with hallux valgus before surgery, and after Hohmann correction osteotomy 20 HOHMANN OSTEOTOMY Postoperative care A compression dressing is applied at the operating room, followed by 5 days immobilisation. After wound healing a short leg walking-cast is applied until radiographic consolidation of the osteotomy side is achieved. Table 1 (Bonney en McNab) Results Hallux valgus (degrees) Range of movement in first MTP Symptoms Function Excellent 0-20 Full Nil Full Good 0-30 Some limitation Occasional Satisfactory Poor >30 Marked limitation or no movement Frequent Bunion present Impaired * The worst result in one category determined the overall result Results The results of the follow-up are described in figure 2. In the group with normal intermetatarsal angles the average hallux valgus angle had been corrected with 10 degrees, from 25 to 15 degrees. The average IMT angle had been corrected 3 degrees, from 11 to 8 degrees. In the group with MPV the mean hallux valgus angle had been corrected 18 degrees, from 35 to 17 degrees and the average IMT angle had been corrected 5 degrees, from 17 to 12 degrees. Of the patients with a normal IMT angle 90 percent of the results was good or excellent, 10 % was poor. Of the patients with MPV 64 % had a good or excellent result, 36 % was poor. Figure 2 One patient with a normal IMT angle had a postoperative infection; the hardware was removed. The patient developed an ankylosis and had revision surgery. She was classified as poor. The following patients in the group with MPV had poor results because of 21 CHAPTER 2 the following: One patient had a congenital spastic hemi-syndrome. She had revision surgery, because of recurrence of hallux valgus after the initial operation. Another had a postoperative infection, the hardware was removed; this patient developed an ankylosis. In the other three patients there was a discrepancy between the subjective score, a painful hallux, slight bunion and the anatomical/objective scores, which were good. Discussion Of the many procedures described for operating hallux valgus, a metatarsal osteotomy is the most frequently used. The objective is rapid and consistent union, with correction of the deformity and relief of pain. Success rates are often comparable. In our group the satisfaction result was 75 %. Comparing the postoperative angles of hallux valgus, we found no significant difference between both groups, namely 15 degrees for patients with a normal IMT angle and 17 degrees for those with MPV. The results in the group patients with MPV are worse. One patient required revision surgery because of failure of the initial procedure. In the other three patients the anatomical correction was satisfactory, the subjective complaints of these patients were not better than before the operation; this appeared to be caused by the width of the foot. The correction of the IMT angle is a result of the method of measurement; the proximal segment of the metatarsal bone is not corrected. The groups are too small for statistical evaluation and the study is retrospective. A prospective study will be necessary for more conclusive data. Nevertheless we cautiously draw the following conclusions: Hohmann osteotomy is a reliable procedure for treating a hallux valgus deformity. Metatarsus primus varus seems a bad prognostic factor for correcting hallux valgus with subcapital osteotomies. In these cases the primary objective should be reduction of the width of the foot. Proximal metatarsal osteotomies seem favourable in these cases. In a study of Chevron and Mitchell osteotomies Meier had a success rate of 94 % when the IMT angle was 12 degrees or less, and 74 % if the IMT angle was greater than 12 degrees.7 A frequent complication in their research group with Chevron osteotomies was avascular necrosis. Manndescribes a crescentic osteotomy of the base of the first metatarsal with distal soft tissue reconstruction.6 A complication could be hallux varus. Meyerson describes a modified Lapidus procedure. Indications are severe MPV with hypermobility of the metatarsocuneiform joint.8 Arthrodesis gives fixed correction of the deformity. Disadvantages are complexity of the procedure, non-union and shortening of the first ray. 22 HOHMANN OSTEOTOMY Overall the results of proximal osteotomies are as good as subcapital osteotomies. Subcapital osteotomies seem to have worse results with IMT angles exceeding 12 to 15 degrees. We recommend to correct hallux valgus with moderate to severe metatarsus primus varus with proximal osteotomies or metatarsocuneiform arthrodesis. 23 CHAPTER 2 References 1. 2. 3. 4. 5. 6. 7. 8. 9. 24 Bonney, G. and Macnab, I.: Hallux valgus and hallux rigidus: A critical survey of operative results. J Bone Joint Surg 34B: 366-385, 1952. Carr, C.R. and Boyd B.M.: Correctional osteotomy for metatarsus primus varus and hallux valgus. J Bone Joint Surg 50A: 1353-1367, 1968. Grace, D., Hughes, J. and Klenerman, L.: A comparison of Wilson and Hohmann osteotomies in the treatment of hallux valgus. J Bone Joint Surg 70(2): 236-242, 1988. Helal, B., Gupta, S.K. and Gojaseni, P.: Surgery for adolescent hallux valgus. Acta Orthop Scand 45: 271295, 1974. Mann, R.A. and Coughlin, M.J.: Adult hallux valgus. In Surgery of the Foot and Ankle, edited by RA Mann and MJ Coughlin. Ed.6 p 176-296. St Louis. Mosbey-Yearbook 1993. Mann, R.A., Rudicel, S. and Graves, S.C.: Repair of hallux valgus with a distal soft-tissue procedure and proximal metatarsal osteotomy. A long term follow up. J Bone Joint Surg 74(A): 124-129, 1992. Meier P.J. and Kenzora J.E.: The risks and benefits of distal first metatarsal osteotomies. Foot & Ankle 6: 717, 1985 Meyerson, M.: Metatarsocuneiform arthrodesis for treatment of hallux valgus and metatarsus primus varus. Orthopaedics 13: 1025-31, 1990. Sangeorzan, B.J. and Hansen, S.T., Jr.: Modified Lapidus procedure for hallux valgus. Foot and Ankle 9: 262266, 1989.) CHAPTER 3 Scarf versus chevron osteotomy in hallux valgus: A randomised controlled trial in 96 patients. Axel Deenik, Peter Pilot, Erwin Brandt, Henk van Mameren, Ruud Geesink, Frits Draijer. Foot Ankle Int. 2007 May;28(5):537-41. 25 CHAPTER 3 Abstract Background The amount of possible correction using a distal osteotomy is limited. The scarf osteotomy should achieve more correction of the intermetatarsal angle (IMA). The purpose of this study is to evaluate if one of the techniques results in a better correction of the IMA and hallux valgus angle (HVA). Methods After informed consent, 96 feet in 83 patients were randomised, 49 scarf and 47 chevron osteotomies were performed. The results were evaluated using the American Orthopedic Foot and Ankle Society (AOFAS) score, radiographic HVA and IMA measurements. Results At 2 years follow-up both groups improved: The AOFAS score in the chevron group from 48 to 89 and in the scarf group from 47 to 91. In the chevron group the HVA was corrected from 30 to 17 degrees, in the scarf group the HVA was corrected from 29 to 18 degrees. In both groups the IMA was corrected from 13 to 10 degrees. The differences were not statistically significant. Three patients in the chevron group developed a partial metatarsal head necrosis. In the scarf group there were 4 cases of Complex Regional Pain Syndrome type 1 against 1 patient in the chevron group. Conclusion After 2 years follow-up no differences of statistical significance could be measured between both groups with respect to the AOFAS score, HVA and IMA. Although both groups showed good to excellent results, we favour the chevron osteotomy because the procedure is technically less demanding. 26 RCT CHEVRON OSTEOTOMY VERSUS SCARF OSTETOMY Introduction More than 100 operation techniques are described for treatment of symptomatic hallux valgus. In case of an active patient without clinical or radiographic arthritis of the metatarsophalangeal (MTP) joint an important surgical decision is between a proximal and a distal osteotomy.3,9 The distal chevron osteotomy is a widely accepted method for the correction of mild to moderate hallux valgus.17 Advantages of this procedure are stability of the osteotomy, rapid healing and minimal shortening.17 Possible disadvantages are avascular necrosis, insufficient correction or recurrence of hallux valgus.10 The amount of possible correction using a distal osteotomy is limited. The scarf osteotomy gained popularity as an alternative stable osteotomy to achieve more correction of the intermetatarsal angle (IMA).1,15 Disadvantages are a more extensive surgical exposure with a longer learning curve.5,12 The scarf osteotomy seems to be a more versatile procedure, although there are multiple potential pitfalls.2 Indications for performing a scarf or chevron overlap. Therefore we have performed a randomised controlled trial (RCT). The purpose of this study is to evaluate if one of the techniques results in a better correction of the IMA, hallux valgus angle (HVA), better function and lower complication rate. Materials and Methods Patient Population Between August 1999 and June 2001 108 feet in 95 consecutive patients were included and randomised. 9 patients cancelled their operation after randomization. 2 patients after a scarf osteotomy and 1 patient after a chevron osteotomy were excluded because they were not operated according to the study protocol. 96 feet in 83 patients were operated and seen for follow-up. Inclusion criteria were patients with a painful bunion and hallux valgus between 18 and 65 years of age and an adequate range of movement. Exclusion criteria were patients with rheumatoid arthritis, failed previous hallux valgus surgery and symptomatic and/or radiological arthritis of the MTP joint.7 48 chevron osteotomies were performed, and 49 scarf osteotomies. There were no differences in both groups regarding age, gender, AOFAS score, HVA and IMA (Table 1). The local medical ethics committee approved the study; all patients received oral and written study information. 27 CHAPTER 3 Table 1 Preoperative data chevron scarf Number patients 47 49 Age 43 45 AOFAS Total 48,4 ± 13,6 (SD) 47.4 ± 13,5 (SD) Pain 16.0 ± 10.6 14.4 ± 10.3 Function 31.4 ± 5.0 30.7 ± 6.8 Alignment 0.9 ± 2.5 1.1 ± 2.8 HVA 30.4 ± 7,7 28.9±7,7 IMA 13.4 ± 3,2 12.8 ±3,2 Operation time 23.6 ± 5.8 29.2 ± 6.7 The values are given as a mean with the standard deviation. Clinical assessment Clinical evaluation data were collected preoperatively and the end results were evaluated at 2 years postoperative. For this purpose the AOFAS score was used.8 This rating scale incorporates subjective and objective factors that describe pain, function and alignment. The total score range from 0 to 100 points. Weight bearing radiographs were obtained. Two observers who were not involved in the surgical procedures examined all patients. 3 patients had a 2-year clinical follow-up but their last X-rays were 9 months postoperative. Because no clinical significant worsening of the corrected hallux developed, these data were used for evaluation. Radiological data Radiological evaluation (figure 1 and 2) was performed according to standardized standing procedures. One examiner measured on the dorsoplantar x-rays the HVA and IMA: The HVA is measured as the angle between the line from the center of the metatarsal base to the center of the first metatarsal head 11 and the line connecting the midpoints of the proximal and distal articular surfaces of the proximal phalanx. The IMA is measured as the angle between the line of MT 1 and the line bisecting the diaphyseal portions of metatarsal 2.16 Surgical procedures All operations were performed with a tourniquet, and spinal anesthesia in day-care and according to protocol. The chevron osteotomy was performed by a medial incision centered over the MTP 1 joint. The dorso-medial cutaneus nerve was protected. The medial capsule was opened longitudinally and a strip of capsule was excised. The medial eminence of the first metatarsal head was removed. A trans-articular lateral capsular release was performed until the hallux was in line with the first metatarsal. A 60-degree V-osteotomy centered in the 28 RCT CHEVRON OSTEOTOMY VERSUS SCARF OSTETOMY first metatarsal head was performed; the capital fragment was displaced laterally. The osteotomy was secured with a K-wire. A medial capsulorraphy was performed. The scarf osteotomy was started with a medial incision over the MTP joint. The dorsomedial cutaneus nerve was protected. The medial emininence was removed and a transarticular lateral capsulotomy was performed. With the oscillating saw a long z-shaped osteotomy was made. The osteotomy was distally and proximally completed with a small osteotome. The distal fragment was lateralized. First the distal mini AO screw was placed, followed by the proximal one. A medial capsulorraphy was performed. Postoperative treatment After removal of the bandage a toe spacer and a night splint were used for three months. Patients were allowed to mobilize on the heel or flat foot during the first six weeks. Statistics Because the data were normally distributed we used the parametric T-test. Figure 1 a. Patient (female 51 years) with intermetatarsal angle of 17 degrees b. 2 year follow-up after chevron osteotomy 29 CHAPTER 3 Figure 2 a. Patient (female 52 years) with intermetatarsal angle of 16 degrees. b. 2 year follow-up after scarf osteotomy Results The chevron and the scarf group showed both a significant improvement in the AOFAS, HVA and IMA score. The assessments according to the AOFAS rating scale, HVA and IMA are in table 2. There were differences between both groups in AOFAS, HVA and IMA, these were not statistical significant. The differences and p-values are in table 3. There was a 5 minutes difference in operation time in favour of the chevron group, mean 24 (SD: 5.8) minutes versus 29 (SD: 6.7) minutes in the scarf group. 30 RCT CHEVRON OSTEOTOMY VERSUS SCARF OSTETOMY Table 2 Postoperative data AOFAS Total chevron scarf 89.0 ± 12.2 91.2 ± 12.1 Pain 37.0 ± 6.2 36.7 ± 7.7 Function 38.1 ± 5.1 39.1 ± 6.8 Alignment 13.3 ± 3.8 13.0 ± 4.1 HVA 17.2 ± 5.8 18.1 ± 5.7 IMA 10.3 ± 1.9 9.9 ± 2.0 The values are given as a mean with the standard deviation. Table 3 AOFAS Total Pain chevron improvement scarf improvement p-value difference 40.5 ± 15,4 43.8 ± 17,9 0.43 21.1 ± 10.3 22.8 ± 12.6 0.474 Function 6.7 ± 6.4 8.7 ± 6.6 0.136 Alignment 12.5 ± 4.2 12.1 ± 5.0 0.715 HVA 13.1 ± 7.0 10.9 ± 7.2 0.13 IMA 3.1 ± 2.7 3.1 ± 2.9 0.97 The values are given as a mean with the standard deviation. Complications In the chevron group two patients developed superficial pin-tract infections. Four patients of the scarf group developed a Complex Regional Pain Syndrome grade I (CRPS) which resolved after desensitization therapy. One patient developed a CRPS grade I after a chevron osteotomy. Three patients in the chevron group developed partial avascular head necrosis, with subchondral cysts but no collapse of the metatarsal head. One of these patients was asymptomatic. Discussion The goal of this randomised controlled trial was to compare the results of scarf and chevron osteotomy with regard to IMA, HVA and AOFAS. In both groups good to excellent results were found regarding to improvement of AOFAS scores, reduction of the HVA and IMA. We found differences between both groups, which were not statistically significant. The complication rates in the chevron and scarf group are equal, although the kind of complications differs. According to literature larger correction of the IMA would be possible using a scarf osteotomy.3,9 Therefore we did not expect to find a comparable IMA correction in both pa31 CHAPTER 3 tient groups. Lateral translation in both osteotomies is limited, because bony contact is essential for adequate fixation. On X-rays the shape of the first metatarsals after a chevron osteotomy differ from those after a scarf osteotomy, first mentioned show valgus in the shaft. Because in the scarf osteotomy correction occurs in the shaft, it results in a more aligned shaft. However, the biomechanical axis and therefore the IMA, are defined by the corrected metatarsal head and not by the shape of the shaft.11 Further we measured the true center of the metatarsal head regardless of the magnitude of the bunionectomy. This method of measurement is mentioned to be the most reliable.11,14 The finding that no difference is found between the amount of correction of the IMA after chevron and scarf osteotomy shows that the average translations of the metatarsal heads in both groups of osteotomies were equal and that there was no difference in correction between a scarf and a chevron osteotomy. In the chevron group the Kirschner wire caused 2 superficial wound infections. With the use of bioabsorbable fixation devices or double threaded hallux valgus screws,4 the inconvenience of pin-tract infections can be prevented. Avascular necrosis of the metatarsal head has developed in three patients (6%) after a chevron osteotomy, although we used a small exposure, without excessive periosteal stripping.6 However, we have mobilized the abductor hallucis and sometimes released the sesamoids on the plantar side to aid their reduction. Maybe this attributed to the frequency of necrosis. Avascular necrosis of the metatarsal head in chevron osteotomies occurs between 0 and 40 percent and can be attributed to a lateral release, periosteal stripping, and the osteotomy.10,13,6 The high frequency of CRPS grade I after a scarf osteotomy have not been reported before. Maybe this is the result of the more extensive approach in the scarf group. These patients needed 9 months for recovery, which was longer than the other patients. At 2 years follow-up there were no residual complaints of CRPS. Two cases in the scarf group developed subluxation of the first metatarsophalangeal joint after initial good correction, however these cases have a good AOFAS score. It may be explained by insufficient transarticular capsulotomy or by creating a rotational deformity during fixation of the osteotomy. Longer follow-up in these patients will show us whether subluxation progresses, and if revision surgery will be necessary. We have 52 cases after a 2-year follow-up with a HVA of more than 15 degrees. These patients had good AOFAS scores, and will probably not improve with further correction. Although sufficient reduction of the HVA was found the remaining valgus could be attributed to the following facts. No additional Akin osteotomy was performed. It is feasible that lateral capsulotomy was insufficient in individual cases. During the operation the surgeon had performed the capsulotomy till the proximal phalanx could be 32 RCT CHEVRON OSTEOTOMY VERSUS SCARF OSTETOMY addressed in line with the first metatarsal. These patients may have needed an open adductor release. In our study recurrences of hallux valgus were seen in patients with insufficient capsulotomy. These cases influenced more negatively the final results than the type of osteotomy performed. Careful surgery and performing all key steps in surgical correction of hallux valgus surgery seem more important than the type of osteotomy one performs. Summary and Conclusion Clinical and radiological results in both groups are good to excellent. Complication rate is comparable although types of complications differ. We favour the chevron osteotomy because the procedure is technically less demanding. We found that the scarf osteotomy is a more demanding technique, although, it did not lead to a higher complication rate. 33 CHAPTER 3 References 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 34 Barouk, L. S.: Scarf osteotomy for hallux valgus correction. Local anatomy, surgical technique, and combination with other forefoot procedures. Foot Ankle Clin, 5(3): 525-58, 2000. Coetzee, J. C.: Scarf osteotomy for hallux valgus repair: the dark side. Foot Ankle Int, 24(1): 29-33, 2003. Coughlin, M. J.: Hallux valgus. Instr Course Lect, 46: 357-91, 1997. Crosby, L. A., and Bozarth, G. R.: Fixation comparison for chevron osteotomies. Foot Ankle Int, 19(1): 41-3, 1998. Dereymaeker, G.: Scarf osteotomy for correction of hallux valgus. Surgical technique and results as compared to distal chevron osteotomy. Foot Ankle Clin, 5(3): 513-24, 2000. Edwards, W. H.: Avascular necrosis of the first metatarsal head. Foot Ankle Clin, 10(1): 117-27, 2005. Hattrup, S. J., and Johnson, K. A.: Subjective results of hallux rigidus following treatment with cheilectomy. Clin Orthop, (226): 182-91, 1988. Kitaoka, H. B.; Alexander, I. J.; Adelaar, R. S.; Nunley, J. A.; Myerson, M. S.; and Sanders, M.: Clinical rating systems for the ankle-hindfoot, midfoot, hallux, and lesser toes. Foot Ankle Int, 15(7): 349-53, 1994. Mann, R. A.: Decision-making in bunion surgery. Instr Course Lect, 39: 3-13, 1990. Meier, P. J., and Kenzora, J. E.: The risks and benefits of distal first metatarsal osteotomies. Foot Ankle, 6(1): 7-17, 1985. Miller, J. W.: Distal first metatarsal displacement osteotomy. Its place in the schema of bunion surgery. J Bone Joint Surg Am, 56(5): 923-31, 1974. Perugia, D.; Basile, A.; Gensini, A.; Stopponi, M.; and Simeonibus, A. U.: The scarf osteotomy for severe hallux valgus. Int Orthop, 27(2): 103-6, 2003. Resch, S.; Stenstrom, A.; and Gustafson, T.: Circulatory disturbance of the first metatarsal head after Chevron osteotomy as shown by bone scintigraphy. Foot Ankle, 13(3): 137-42, 1992. Schneider, W.; Csepan, R.; and Knahr, K.: Reproducibility of the radiographic metatarsophalangeal angle in hallux surgery. J Bone Joint Surg Am, 85-A(3): 494-9, 2003. Schoen, N. S.; Zygmunt, K.; and Gudas, C.: Z-bunionectomy: retrospective long-term study. J Foot Ankle Surg, 35(4): 312-7, 1996. Smith, R. W.; Reynolds, J. C.; and Stewart, M. J.: Hallux valgus assessment: report of research committee of American Orthopaedic Foot and Ankle Society. Foot Ankle, 5(2): 92-103, 1984. Trnka, H. J.; Zembsch, A.; Easley, M. E.; Salzer, M.; Ritschl, P.; and Myerson, M. S.: The chevron osteotomy for correction of hallux valgus. Comparison of findings after two and five years of follow-up. J Bone Joint Surg Am, 82-A(10): 1373-8, 2000. CHAPTER 4 Correction in scarf and chevron osteotomy is equal in moderate and severe hallux valgus: A randomized controlled trial in 136 patients. Axel Deenik, Henk van Mameren, Enrico de Visser, Maarten de Waal Malefijt, Frits Draijer, Rob de Bie. Foot Ankle Int. 2008 Dec;29(12):1209-15. 35 CHAPTER 4 Abstract Background Chevron osteotomy is a widely accepted osteotomy for correction of hallux valgus.19 Algorithms were developed to overcome the limitations of distal osteotomies. Scarf osteotomy became popular as a versatile procedure that should be able to correct most cases of acquired hallux valgus. The purpose of this study is to evaluate whether in patients with moderate or severe hallux valgus a scarf osteotomy results in a better correction of hallux valgus angle (HVA) and intermetatarsal angle (IMA) as compared to chevron osteotomy. Methods After informed consent, 136 feet in 115 patients were randomized, 66 scarf and 70 chevron osteotomies including bunionectomy, lateral transarticular release and medial capsulorraphy were performed. Deformities of patients were classified as mild, moderate and severe according to IMA flowcharts, and both groups were compared with independent t-tests. The results were measured using radiographic HVA, IMA and distal metatarsal articular angle (DMAA) measurements. Results There were no statistical differences in HVA, IMA and DMAA between scarf and chevron osteotomy in mild to moderate hallux valgus. In severe hallux valgus chevron osteotomy corrected HVA better than scarf osteotomy, although this group consisted of twelve patients. Five patients in the chevron group and seven in the scarf group developed subluxation of the metatarsophalangeal joint. Conclusion In patients with moderate and severe hallux valgus the results of scarf and chevron osteotomy do not differ. Subluxation of the first metatatarsophalangeal joint was the main cause for insufficient correction. We favour the chevron osteotomy because it is less invasive, without sacrificing correction of HVA and IMA. 36 RCT SUBGROUP ANALYSIS Introduction Chevron osteotomy is a widely accepted osteotomy for correction of hallux valgus.19 Operative procedures were developed to overcome the limitations of distal osteotomies. Proximal osteotomies allow correction of higher intermetatarsal angle (IMA), at the expense of decreased stability. Scarf osteotomy has become popular as a versatile procedure that should be able to correct higher IMA with the advantage of intrinsic stability. Radiological assessment is an acknowledged tool with variables like congruency, hallux valgus angle (HVA), intermetatarsal angle and distal metatarsal angle (DMAA). These radiological parameters are used with different cut-off points in algorithms to choose between distal, shaft and proximal osteotomy. These algorithms differ in detail; IMA cutoff points are used in the range between 11-20 degrees, for classification in mild, moderate and severe hallux valgus.10,14 However, no statistical difference was demonstrated in correction of IMA and HVA in randomized controlled trials comparing tarsometatarsal arthrodesis versus distal osteotomy8 and distal versus shaft osteotomy.6 These studies were performed in hallux valgus groups where mild deformities were included. There are no randomized controlled trials between distal and either shaft or proximal osteotomy in patients with moderate to severe hallux valgus. Therefore, it should be tested whether shaft osteotomy results in better correction than distal osteotomy in moderate and severe hallux valgus. Moreover, the validity of IMA in preoperative planning should be assessed. This study was conducted, because our previous report did not find differences. Because mild deformities might influence our results, we did need a bigger group in order to test differences between scarf and chevron osteotomy in subgroups. Algorithms for more aggressive surgery are justified in moderate and severe hallux valgus deformities to obtain better correction of HVA. However, it is recognized that clinical and radiological parameters are lacking in evaluating operative results.16,3 In spite of this, radiological parameters are used in daily practice to consider more aggressive surgery in order to obtain better correction. Therefore, radiological parameters are used in our study to evaluate whether in patients with moderate or severe hallux valgus scarf osteotomy results in a better correction of HVA and IMA, as compared to chevron osteotomy. The outcome will be compared according to preoperative IMA. Materials and Methods Between August 1999 and September 2004 141 feet in 120 consecutive patients, including bilateral cases, were included in this study. Randomization occurred upon inclusion by a randomization scheme. This was made at the start of the study after perfoming a power analysis. Three cases were excluded after a scarf osteotomy and one case after a chevron osteotomy because they were not operated according to the study protocol. One patient 37 CHAPTER 4 with scarf osteotomy refused to show up for follow-up because of psychologic problems and debilitating chronic regional pain syndrome. 70 chevron osteotomies and 66 scarf osteotomies were seen at follow-up after 2.6 years (range 23 to 39 months) after surgery. Preoperative IMA was used to define patient groups; mild hallux valgus was defined with IMA of 11 degrees or lower, moderate hallux valgus was defined with IMA from 11 to 16 degrees, and severe hallux valgus was defined with IMA from 17 degrees or more. Clinical assessment procedures, radiological data retrieval, American Orthopaedic Foot and Ankle Society scores, operative procedures and postoperative treatment are described in detail.6 The local medical ethics committee approved the study; all patients received oral and written information about the study and gave their written consent. Radiology Radiological evaluation was performed according to standardized procedures. The unbiased first author, who did not perform surgery, measured the HVA and IMA on the dorsoplantar X-rays:15 HVA was measured as the angle between the line connecting the centre of the base to the centre of the head of MT1 and the line connecting the midpoints of the proximal and distal articular surfaces of the proximal phalanx. The IMA is defined as the angle between the longitudinal axis of MT1 and the line bisecting the distal and proximal diaphyseal portions of MT2.15 The distal metatarsal articular angle (DMAA) was measured according to standard guidelines.5 Markers were placed at the most medial and most lateral extent of the metatarsal articular surface. A line was drawn connecting the two markers. Another line was drawn perpendicular to this line. The angle between the perpendicular line and the longitudinal axis of MT1 of the first metatarsal is the DMAA. Data consist of the mean of two independent measurements. We classified subluxation of the first MTP joint if the lateral articular border of the proximal phalanx passes the lateral articular border of the first metatarsal. Operative procedures All operations were performed with a tourniquet, and spinal anaesthesia in day-care and according to protocol. Pre-existent deformities did not change the operative procedure. The chevron osteotomy was performed through a medial incision centred over the first metatarsophalangeal joint. (MTPJ1) The dorso-medial cutaneus nerve was protected. The medial capsule was opened longitudinally and a strip of capsule was excised. The medial eminence of the first metatarsal head was removed. A trans-articular transverse lateral release was performed until the proximal phalanx was in line with MT1. A 60degree V-osteotomy centred in the first metatarsal head was performed; the capital 38 RCT SUBGROUP ANALYSIS fragment was displaced laterally. The osteotomy was secured with a percutaneous Kwire. A medial capsulorraphy was performed to secure soft-tissue realignment. The scarf osteotomy was started with a medial incision over the MTPJ1. The dorsomedial cutaneus nerve was protected. The medial eminence on MT1 was removed and a transarticular transverse lateral release was performed. With the oscillating saw a long zshaped osteotomy was made. The osteotomy was distally and proximally completed with a small osteotome. The distal fragment was lateralized. First the distal mini AO screw was placed, followed by the proximal one. A medial capsulorraphy was performed. Postoperative treatment After removal of the bandage a toe spacer and a night splint were used for three months. Patients were allowed to walk only on the heel or flat foot during the first six weeks. Statistics Normal data distribution was tested using Levene’s test. An independent t-test was used to compare scarf versus chevron in mild, moderate and severe hallux valgus (IMA cut-off points 11 and 17 degrees, table 1). Table 1. Overall group: Scarf versus chevron Variable Chevron (N=70) Scarf (N=66) p Hallux valgus angle Preoperative Postoperative 30.5 ± 6.7 17.2 ± 5.2 30.0 ± 6.9 19.0 ± 7.7 0.66 0.12 Intermetatarsal angle Preoperative Postoperative 13.4 ± 2.4 9.5 ± 2.0 13.1 ± 2.6 9.4 ± 2.2 0.49 0.65 Distal metatarsal articular angle Preoperative Postoperative 13.0 ± 6.9 12.4 ± 6.3 12.1 ± 6.8 12.1 ± 6.8 0.47 0.80 Subluxated joint Preoperative Postoperative 61 5 59 7 Kitaoka Preoperative Postoperative 46 86 47 88 Complications Avascular necrosis CRPS 3 1 0 7 0.61 0.38 39 CHAPTER 4 Results There was significant improvement in correction of the HVA and IMA in scarf and chevron osteotomies in patients with mild, moderate and severe hallux valgus. In mild and moderate hallux valgus, pre- and postoperative improvement of HVA and IMA between scarf and chevron osteotomy differences did not reach statistical significance. The severe hallux valgus group consisted of twelve patients; the statistically significant difference was reached in favour of the chevron osteotomy (Table 2) in postoperative HVA and correction of HVA. scarf osteotomy resulted in better correction of IMA; this finding was not statistically significant. Table 2. IMA severity: Chevron versus scarf Variable Chevron Scarf p value Mild (IMA < 11) N=9 N=12 Hallux valgus angle Preoperative Postoperative Correction 25.8 ± 6.5 14.0 ± 5.1 11.8 ± 2.4 25.3 ± 4.9 14.0 ± 5.8 11.3 ± 6.8 0.83 >0.99 0,83 Intermetatarsal angle Preoperative Postoperative Correction 9.7 ± 0.7 7.1 ± 1.5 2.6 ± 1.1 9.8 ± 0.6 7.5 ± 1.6 2.3 ± 1.6 0,60 0,58 0,72 Moderate (11<IMA < 17) N=55 N=48 Hallux valgus angle Preoperative Postoperative Correction 30.4 ± 6.1 17.6 ± 5.2 12.8 ± 6.2 30.3 ± 6.6 19.4 ± 7.6 10.9 ± 6.3 0.93 0.16 0.12 Intermetatarsal angle Preoperative Postoperative Correction 13.4 ± 1.4 9.6 ± 1.6 3.8 ± 1.7 13.2 ± 1.6 9.6 ± 2.1 3.6 ± 2.2 0.41 0.89 0.61 Severe (IMA>16) N=6 N=6 Hallux valgus angle Preoperative Postoperative Correction 39.3 ± 3.6 19.3 ± 4.3 20.0 ± 4.6 38.2 ± 4.4 26.3 ± 6.3 11.8 ± 5.0 0.63 0.047 0,01 Intermetatarsal angle Preoperative Postoperative Correction 18.2 ± 1.0 12.0 ± 2.2 6.2 ± 1.9 18.5 ± 2.0 11.2 ± 1.7 7.3 ± 1.8 0.72 0.48 0.30 40 RCT SUBGROUP ANALYSIS All 120 cases in moderate and severe group had non-congruent joints preoperative. The sixteen cases with preoperative congruent joints were not overcorrected. Of 136 cases, twelve cases developed recurrence of hallux valgus, with an average HVA of 31 degrees, because of subluxation of the MTPJ1 after initial adequate correction. Five of these patients were in the chevron group and all were preoperative classified as moderate hallux valgus. Seven of these patients were in the scarf group, two cases had preoperative severe and five moderate hallux valgus. The remaining 90 percent of the moderate and severe group had an average postoperative HVA of 17 degrees with congruent joints. The patients with recurrence were offered revision surgery, which they were not inclined to undergo because an acceptable reduction of pain after the first operative intervention was reached. Figure 1 and Table 2 show that patients with the higher IMA do have higher postoperative HVA. However, in all groups range of distribution is evident with positive and negative outliers. Figure 1. Intermetatarsal angle group plotted versus the outcome hallux valgus angle Clinical data are described in our previous report; in AOFAS score no differences between scarf and chevron osteotomy were found (table 1). However, important differences were found concerning complications: We changed our operative technique during the study taking more care of the plantar blood supply in chevron osteotomy and 41 CHAPTER 4 thereafter we saw no more cases with avascular necrosis. In comparison with our previous study the number of Complex Regional Pain Syndrome (CRPS) in patients with scarf osteotomy did increase from four to seven patients, six of these were mild (CRPS 1) and one was moderate. In the chevron group one patient with mild CRPS did remain equal in comparison with our previous report. Five bilateral cases randomized at one side chevron, while the other foot was randomized for scarf osteotomy. All these five patients found that recovery after surgery was more quickly in the foot corrected by chevron osteotomy, however, radiologically nor by AOFAS clinical differences could be found at the follow-up moments. Discussion The purpose of this study was to evaluate whether in patients with moderate or severe hallux valgus a scarf osteotomy results in a better correction of HVA and IMA as compared to chevron osteotomy. In patients with moderate and severe hallux valgus no differences were found between scarf and chevron osteotomy. The amount of CRPS in scarf osteotomy did raise concern. In our study we found no differences between scarf and chevron osteotomy in correction of HVA and IMA in patients with moderate and severe hallux valgus. Our findings are consistent with these of previous randomized controlled trials.8,6 However, this is the first randomized trial to compare distal versus shaft osteotomy in patients with mild, moderate and severe hallux valgus. Patients with severe hallux valgus obtained a better correction with chevron osteotomy than patients who received a scarf osteotomy, although a group of twelve patients is too small for definitive conclusions. However, scarf osteotomy was expected to correct moderate and severe hallux valgus better.14,9 Possible explanation is that Perugia combined scarf osteotomy with open lateral release and Akin osteotomy.11 These additional operative procedures might be a more important factor in obtaining results than the type of osteotomy. Our experience was that the advantage of more proximal correction was undone because the narrower metatarsal shaft allowed for less lateral translation of the distal fragment of MT1 than the wider subcapital fragment.6 In cases with a wide metatarsal shaft, more translation could be achieved with the scarf osteotomy; a wide subcapital fragment was seen more often, which allowed more translation in chevron osteotomy. In scarf osteotomy rotation of the distal fragment is possible; this allows more correction of the distal fragment with a small increase in distal metatarsal articular angle. This had been performed in part of the moderate and severe cases. We could not find an influence of refining of technique in these cases. 42 RCT SUBGROUP ANALYSIS Clinical improvement between patients who received scarf or chevron osteotomy did not change in comparison to our previous study. However, an important difference was the higher incidence of CRPS in the scarf osteotomy group. Most cases were mild and recovered between 6 months and 1 year. The difference in CRPS between scarf and chevron did surprise us, because the extra soft tissue damage in the scarf osteotomy seems small in comparison to the chevron procedure. We are surprised that we did not find other reports with similar findings. Five bilateral differently operated patients preferred chevron over scarf osteotomy, because recovery was quicker in chevron osteotomy. At follow-up no radiographic or clinical differences were found. Slow recovery can be a downside in more extensive surgery and should be taken into consideration in preoperative planning. In our previous study complications between both procedures were equal. Avascular necrosis occurred in the chevron group in the early phase of the study. By refining our technique this complication could be intercepted by taking care of plantar vasculair blood supply. The lower incidence of complications is now in favour of the chevron group. The IMA is acknowledged as an important factor in the prediction of the possible reduction of the hallux valgus deformity and is, therefore, used as a parameter for classification by algorithms. Table 2 and Figure 1 show that patients with moderate and severe hallux valgus are associated with higher pre- and postoperative HVA, which corresponds with the prediction by algorithms. In patients with moderate and severe hallux valgus 90 percent good correction was achieved with scarf and chevon osteotomy. In the remaining ten percent of patients with moderate and severe hallux valgus recurrences occurred in ten percent, which corresponds with literature.1 These twelve cases had preoperative IMA from 11 to 22 degrees and their preoperative HVA were in a range from 30 to 44 degrees. This range corresponds with the boundaries for moderate to severe HVA.14,2 The prevalence of secondary subluxation within this selected range was 19 percent. Although pain reduction for these 12 patients was acceptable, more aggressive surgery seems indicated. We should select patients prone for subluxation within this IMA range more accurate, within current cut-off points 80 percent is treated to aggressively. Subluxation of the sesamoid on the PA X-ray might be an option,4 although other studies found it less reliable on X-rays because of rotational deformity.18,20 A possible explanation for secondary subluxation could be that transarticular release was insufficient. Than it is likely that the lateral sesamoid and the adductor hallucis were not completely released.17 Patients with moderate to severe hallux valgus and subluxation are usually corrected with shaft or proximal osteotomy including a distal soft tissue procedure (DSTP).10 Resch concluded that DSTP, although radiologically significant, did not have an effect on clinical parameters,13 which corresponds with our findings. However, this concerns short-term follow-up, and patients with subluxated joints might predispose to artritis. It is clinically relevant to lower subluxation rate (19 percent in moderate to 43 CHAPTER 4 severe hallux valgus in our study), without exposing patients to excessive operative procedures (81 percent in the same group), because of possible complications like hallux varus and CRPS. An open DSTP might increase the indication for both types of osteotomies.12 In case of an open DSTP the literature remains controversial about which structures need to be released. The other possibility for secondary subluxation could be that the biomechanical axis was insufficiently restored, because translation of the distal fragment in distal and shaft osteotomy was limited. Alignment of the first ray was restored after surgery, cases of recurrence occurred after three months follow-up. We concluded that insufficient lateral release was a plausible cause in cases with secondary subluxation. Operative methods to improve correction the biomechanical axis are following; a proximal osteotomy does allow more translation and rotation of the distal fragment, although recurrences of hallux valgus from four percent and more are still described in these procedures.7 Another option would be to perform an Akin osteotomy to enhance alignment in the proximal phalanx. Knowledge and guidelines regarding hallux valgus correction surgery did improve quality of correction. In our study IMA was correlated with HVA outcome; however, cut-off points were less accurate to predict cases that develop recurrences. Radiological parameters used in algorithms provide insight of factors to consider in preoperative planning of hallux valgus surgery. However, there is still a lack of evidence which cut-off point and operative procedure to choose. Operative strategy should provide an optimal balance between adequate correction and prevention of recurrences. Possible complications of more aggressive surgery should be considered carefully with their possible benefit in achieving better correction. In young and high-demand patients with severe hallux valgus deformity and subluxated joints, we prefer open DSTP as primary procedure; release of the soft tissue contracture partially adresses the varus position of the first metatarsal bone. The remaining deformity does need correction by osteotomy. Ten percent of patients likely benefit from more aggressive surgery. A downside of more extensive foot procedures seems slow recovery because of increased swelling and pain. We now discuss this dilemma preoperatively with patients indicated for surgery. Further research is necessary to improve identification of patients that are predisposed to secondary subluxation. An optimal operative strategy should be evidence-based, provide information on which structures need to be released laterally, on the kind of osteotomy and on the necessity of an Akin osteotomy. 44 RCT SUBGROUP ANALYSIS Conclusion In patients with moderate and severe hallux valgus the results of scarf and chevron osteotomy do not differ. Subluxation of the MTPJ1 was the main cause for insufficient correction. We favour the chevron osteotomy because it is less invasive, without sacrificing correction of HVA and IMA. The rate of CRPS in the scarf osteotomy group did raise concern. The use of IMA to predict recurrences was limited. 45 CHAPTER 4 References 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 46 Austin, D. W., and Leventen, E. O.: A new osteotomy for hallux valgus: a horizontally directed “V” displacement osteotomy of the metatarsal head for hallux valgus and primus varus. Clin Orthop Relat Res, (157): 25-30, 1981. Bar-David, T., and Trepal, M. J.: A retrospective analysis of distal Chevron and Basilar osteotomies of the first metatarsal for correction of intermetatarsal angles in the range of 13 to 16 degrees. J Foot Surg, 30(5): 450-6, 1991. Button, G., and Pinney, S.: A meta-analysis of outcome rating scales in foot and ankle surgery: is there a valid, reliable, and responsive system? Foot Ankle Int, 25(8): 521-5, 2004. Coughlin, M. J.: Hallux valgus. J Bone Joint Surg Am, 78(6): 932-66, 1996. Coughlin, M. J., and Freund, E.: Roger A. Mann Award. The reliability of angular measurements in hallux valgus deformities. Foot Ankle Int, 22(5): 369-79, 2001. Deenik, A. R.; Pilot, P.; Brandt, S. E.; van Mameren, H.; Geesink, R. G. T.; and Draijer, W. F.: Scarf versus Chevron osteotomy in hallux valgus. A randomised controlled trial in 96 patients. Foot Ankle Int, 28(5): 537-541, 2007. Easley, M. E.; Kiebzak, G. M.; Davis, W. H.; and Anderson, R. B.: Prospective, randomized comparison of proximal crescentic and proximal chevron osteotomies for correction of hallux valgus deformity. Foot Ankle Int, 17(6): 307-16, 1996. Faber, F. W.; Mulder, P. G.; and Verhaar, J. A.: Role of first ray hypermobility in the outcome of the Hohmann and the Lapidus procedure. A prospective, randomized trial involving one hundred and one feet. J Bone Joint Surg Am, 86-A(3): 486-95, 2004. Kristen, K. H.; Berger, C.; Stelzig, S.; Thalhammer, E.; Posch, M.; and Engel, A.: The SCARF osteotomy for the correction of hallux valgus deformities. Foot Ankle Int, 23(3): 221-9, 2002. Mann, R. A.: Decision-making in bunion surgery. Instr Course Lect, 39: 3-13, 1990. Perugia, D.; Basile, A.; Gensini, A.; Stopponi, M.; and Simeonibus, A. U.: The scarf osteotomy for severe hallux valgus. Int Orthop, 27(2): 103-6, 2003. Petje, G.; Steinbock, G.; and Schiller, C.: Radiographic analysis of metatarsus primus varus. 45 feet followed 15 months after distal metatarsal osteotomy and lateral soft-tissue release. Acta Orthop Scand, 68(6): 567-70, 1997. Resch, S.; Stenstrom, A.; Reynisson, K.; and Jonsson, K.: Chevron osteotomy for hallux valgus not improved by additional adductor tenotomy. A prospective, randomized study of 84 patients. Acta Orthop Scand, 65(5): 541-4, 1994. Robinson, A. H., and Limbers, J. P.: Modern concepts in the treatment of hallux valgus. J Bone Joint Surg Br, 87(8): 1038-45, 2005. Smith, R. W.; Reynolds, J. C.; and Stewart, M. J.: Hallux valgus assessment: report of research committee of American Orthopaedic Foot and Ankle Society. Foot Ankle, 5(2): 92-103, 1984. SooHoo, N. F.; Shuler, M.; and Fleming, L. L.: Evaluation of the validity of the AOFAS Clinical Rating Systems by correlation to the SF-36. Foot Ankle Int, 24(1): 50-5, 2003. Stamatis, E. D.; Huber, M. H.; and Myerson, M. S.: Transarticular distal soft-tissue release with an arthroscopic blade for hallux valgus correction. Foot Ankle Int, 25(1): 13-8, 2004. Talbot, K. D., and Saltzman, C. L.: Assessing sesamoid subluxation: how good is the AP radiograph? Foot Ankle Int, 19(8): 547-54, 1998. Trnka, H. J.; Zembsch, A.; Easley, M. E.; Salzer, M.; Ritschl, P.; and Myerson, M. S.: The chevron osteotomy for correction of hallux valgus. Comparison of findings after two and five years of follow-up. J Bone Joint Surg Am, 82-A(10): 1373-8, 2000. Weijers, R. E.; Kessels, A. G.; Walenkamp, G. H.; van Mameren, H.; and Kemerink, G. J.: Effect of tube angulation on the measurement of intermetatarsal angles. J Am Podiatr Med Assoc, 95(4): 370-5, 2005. CHAPTER 5 Hallux valgus angle as main predictor for correction of hallux valgus Axel Deenik, Enrico de Visser, Jan-Willem Louwerens, Maarten de Waal Malefijt, Frits Draijer, Rob de Bie. BMC Musculoskelet Disord. 2008 May 15;9:70. 47 CHAPTER 5 Abstract Background It is recognized that different types of hallux valgus exist. Classification occurs with radiographic and clinical parameters. Severity of different parameters is used in algorithms to choose between different surgical procedures. Because there is no consensus about each parameter nor their cut-off point we conducted this study to analyze the influence of these variables on the postoperative hallux valgus angle. Methods After informed consent 115 patients (136 feet) were included. Bunionectomy, osteotomy, lateralization of the distal fragment, lateral release and medial capsulorraphy were performed in all patients. Data were collected on preoperative and postoperative HVA, IMA and DMAA measurements. Two-year follow-up data were evaluated with logistic regression and independent t-tests. Results Preoperative HVA was significant for prediction of postoperative HVA in logistic regression. IMA and DMAA were not significant for prediction of postoperative HVA in logistic regression, although they were significantly increased in larger deformities. In patients with preoperative HVA of 37 degrees or more, satisfactory correction could be obtained in 65 percent. The other nine of these 26 patients developed subluxation. Conclusion The preoperative HVA was the main predictor for correction of hallux valgus, correction rate declined from preoperative HVA of 37. IMA and DMAA did have a minor role in patients with preoperative HVA lower than 37 degrees, however, likely contributed to preoperative HVA of 37 degrees or more. 48 REGRESSION ANALYSIS OF PREOPERATIVE PARAMETERS Background About 120 different operation techniques are described for the treatment of symptomatic hallux valgus. However, these procedures result in a 10 percent recurrence rate.2 Radiographic and clinical parameters, like hallux valgus angle (HVA), intermetatarsal angle (IMA) and distal metatarsal articular angle (DMAA) and tarsometatarsal (TMT) hypermobility, have been developed to identify different types of hallux valgus. Severity of each parameter is based on cut-off points and used in algorithms to choose between different surgical procedures.13,9 Radiographic cut-off points lie between 20-40 degrees for HVA, 11-20 degrees for IMA and 10-15 degrees for DMAA. Evidence of algorithms are derived from few retrospective studies.10 Outcomes of other studies do not support the validity of individual features such as TMT hypermobility7, IMA7 and DMAA4. Randomized controlled trials show no difference in correction between Lapidus and distal osteotomy nor shaft and distal osteotomy.6,7 It is questionable if these radiological parameters need to be corrected, or if the cut-off points used for the HVA, IMA or DMAA are correct. Therefore, the influence of parameters on the hallux valgus angle should be evaluated and algorithms should be tested. In analyzing parameters it is necessary to choose an outcome parameter. AOFAS8 score is used in evaluating results, the validity is limited because of overemphasis on evaluating pain.16 Meta-analysis showed that rating scales lack in reporting the results of clinical studies.3 Because the hallux valgus angle is the main derivative of hallux valgus, the HVA is an objective parameter for evaluation of correction obtained through surgery. Algorithms are justified for more aggressive surgery in moderate and severe hallux valgus deformities to obtain better correction of HVA. However, it is recognized that clinical and radiological parameters are lacking in evaluating surgical results.16, 3 The purpose of this study is to evaluate the influence of parameters before surgery on the HVA after surgery. Materials and methods Between August 1999 and September 2004 141 feet in 120 consecutive patients, including bilateral cases were randomized. Inclusion criteria were patients with a painful bunion and hallux valgus between 18 and 65 years of age and an adequate range of movement. Exclusion criteria were patients with rheumatoid arthritis, failed previous hallux valgus surgery and symptomatic and/or radiological osteoarthritis of the MTP joint. Three cases were excluded after a scarf osteotomy and one case after a chevron osteot- 49 CHAPTER 5 omy because they were not operated according to study protocol. One case with scarf osteotomy refused to attend follow-up because of psychiatric problems and debilitating chronic regional pain syndrome (CRPS). 70 chevron osteotomies and 66 scarf osteotomies were seen at follow-up 2,4 years (range 23-39 months) after surgery. Osteotomy, lateralization of the distal fragment, bunionectomy, transarticular lateral release and medial capsulorraphy were performed according to protocol6 and not changed for additional radiographic deformities. Clinical assessment procedures, AOFAS scores, radiological data retrieval, surgical procedures and postoperative treatment are described in detail.6 The local medical ethics committee approved the study; all patients received oral and written study information and gave their written consent. Radiology Radiological evaluation was performed according to standardized procedures. One examiner measured the HVA and IMA on obtained dorsoplantar x-rays: The HVA was measured as the angle between the line from the center of the metatarsal base to the center of the first metatarsal head and the line connecting the midpoints of the proximal and distal articular surfaces of the proximal phalanx. The IMA was measured as the angle between the line of MT 1 and the line bisecting the diaphyseal portions of metatarsal two.15 The distal metatarsal articular angle was measured according standard guidelines.5 Points are placed at the most medial and most lateral extent of the metatarsal articular surface. A line is drawn connecting the two points. Another line is drawn perpendicular on this line. The angle between the perpendicular line and the longitudinal axis of the first metatarsal is the DMAA. The mean of two independent measurements by one reviewer was calculated. Subluxation of the first MTP joint was classified when the lateral articular border of the proximal phalanx passes the lateral articular border of the first metatarsal Statistics Data were tested for normality with Levene’s test for equality of variances. In case of normal data distribution an independent t-test was used to assess differences between HVA, IMA and DMAA in Chevron versus Scarf osteotomy. Operation results were analyzed by means of logistic regression correcting for age, gender, HVA, IMA and DMAA. Finally, pre-operative HVA, IMA and DMAA scores were plotted versus postoperative HVA to gain insight into the technical limitations of both osteotomies. 50 REGRESSION ANALYSIS OF PREOPERATIVE PARAMETERS Results Pre- and postoperative data were normally distributed between both groups before and after correction of hallux valgus (table 1). Regression analysis showed a significant influence of preoperative HVA, but no influence from IMA, DMAA, age, osteotomy and gender on hallux valgus angle after surgery. Figure 1 shows the relation between pre- and postoperative HVA. Correction decreased with an HVA of 37 degrees or more. Consequently, HVA of 37 degrees was used as the cut-off point, classifying these cases as severe hallux valgus. Patients (19 %) with a preoperative HVA of 37 degrees or more have a worse postoperative HVA than patients (81%) with an HVA of 36 degrees or less (table 2). Table 1. Scarf versus Chevron. Normal distribution of data Variable Chevron (N=70) Scarf (N=66) Male Female 9 61 9 57 Age 42.0 ± 12.1 45.4 ± 13.1 0.858 Hallux valgus angle Preoperative Postoperative 30.5 ± 6.7 17.2 ± 5.2 30.0 ± 6.9 19.0 ± 7.7 0.660 0.124 Intermetatarsal angle Preoperative Postoperative 13.4 ± 2.4 9.5 ± 2.0 13.1 ± 2.6 9.4 ± 2.2 0.490 0.648 Distal metatarsal articular angle Preoperative Postoperative 13.0 ± 6.9 12.4 ± 6.3 12.1 ± 6.8 12.1 ± 6.8 0.469 0.803 AOFAS Preoperative Postoperative 46 ± 13.6 86 ± 20.4 47 ± 13.4 88 ± 14.6 0.61 0.38 p Table 2. Overall group: HVA<=36 versus HVA>36 Variable HVA<37 (n=110) HVA=>37 (n=26) Hallux valgus angle Preoperative Postoperative Change 27.8 ± 4.6 16.5 ± 5.5 11.3 ± 5.7 40.9 ± 3.3 25.0 ± 6.8 16.0 ± 6.8 Intermetatarsal angle Preoperative 12.8 ± 2.2 14.8 ± 3.0 Distal metatarsal articular angle Preoperative 11.2 ± 6.0 18.3 ± 7.3 51 CHAPTER 5 Figure 1 boxplot: Preoperative hallux valgus angle versus postoperative hallux valgus angle Although IMA and DMAA are not significant in regression analysis, these parameters are significantly increased in patients with HVA of 37 degrees or more (table 2). Therefore IMA is plotted versus postoperative HVA in figure 2, and DMAA is plotted versus postoperative HVA in figure 3. Preoperative IMA suggest a cut-off point of 17 degrees, although there are positive and negative outliers in all groups. In the severe hallux valgus group 65 % had a congruent joint with a mean HVA of 20 degrees that increased 1 degree from 3 months postoperative till last follow-up. The remaining 35 % of patients had developed subluxation of the MTPJ with a mean HVA of 32 degrees. Mild and moderate cases tend to keep a constant HVA from 3 months till last follow-up. Severe cases tend to progress after 3 months. All severe recurrences occurred in cases that developed subluxation of the metatarsophalangeal joint (MTPJ) after initial good correction. These twelve cases were nine percent of the overall group, subdivided by three of 110 cases (3 %) with a HVA below 37 degrees, and nine (35 %) of 26 cases with a HVA of 37 degrees or more. 52 REGRESSION ANALYSIS OF PREOPERATIVE PARAMETERS Figure 2 boxplot: Preoperative intermetatarsal angle versus postoperative hallux valgus angle Figure 3 boxplot: Preoperative distal metatarsal articular angle versus postoperative hallux valgus angle 53 CHAPTER 5 Discussion We found the preoperative HVA as main predictor for correction of hallux valgus. IMA and DMAA did not predict outcome, although they were increased in severe hallux valgus. In one third of the patients with severe hallux valgus occured subluxation. Ninety-one percent of the patients were successfully corrected with an osteotomy and transarticular lateral release. The nine percent recurrence of hallux valgus in our study is comparable with reports in the literature.2 Mann was the first to publish limitations of McBride procedure in cases with high IMA,13 and therefore advised in these cases to combine DSTP with proximal osteotomy.13 Coughlin combined HVA with IMA in preoperative planning.9 Cut-off points differ,13,9 and the influence of different parameters in surgery is not published. To our knowledge this is the first study that performed regression analysis on different radiographic parameters. Preoperative HVA was found as main predictor for correction of hallux valgus. We found a cut-off point of preoperative HVA of 37 degrees. IMA and DMAA were mildly increased under 37 degrees, and three of 110 cases developed subluxation of the MTPJ. The indication for distal and shaft osteotomy and transarticular lateral release can be extended till HVA of 37 degrees. This finding is clinically relevant, because the main parameter for decision-making was tested for these osteotomies. Although distal osteotomy leads to a lower rate of CRPS,6 other studies warn for possible complications of proximal osteotomy.12 The best treatment for patients with HVA exceeding 37 degrees need to be tested. In patients with HVA of 37 degrees or more nine of 26 cases developed subluxation of the MTPJ. Likely an open release of the adductor and sesamoid suspensory ligament would have resulted in better correction.11 True proximal osteotomy or Lapidus procedure can further improve correction. Patients with subluxated MTPJ were offered revision surgery. However, all patients were not motivated for re-operation because they felt pain reduction was adequate and they were able to wear shoes. The IMA was not a significant predictor for the postoperative hallux valgus angle in logistic regression, but was significantly increased in patients with severe hallux valgus. In figure 2 there seems a cut-off point at IMA of 17 degrees, although outliers are found with lower IMA. Early reports mentioned that higher IMA could be secondary to metatarsal deviation in development of hallux valgus, instead of being a causative factor of hallux valgus.1 In HVA over 37 degrees, correction of IMA might play a role. The DMAA was not significant for prediction of the postoperative hallux valgus angle in logistic regression, but was significantly increased in patients with severe hallux valgus. 54 REGRESSION ANALYSIS OF PREOPERATIVE PARAMETERS Figure 3 showed that increasing DMAA correlated with increasing HVA, although outliers were found with lower DMAA. Congruency was used to describe subluxated joints after surgery, but because there is no scale for congruency it was not used in logistic regression. We found DMAA could be measured reliably when the metatarsal head has a flat shape. However, in a round metatarsal head it is difficult to assess the medial point of the articular surface. Another factor which influences the medial point of the articular surface is cartilage and joint degeneration after subluxation in the MTP joint.17 The postoperative DMAA could be confounded in cases with aggressive bunionectomy, which made determination of the medial articular surface more difficult. Preoperative HVA is the main predictor in correction of hallux valgus. More than 80 percent of the patients can be corrected with distal osteotomy and capsulotomy. In patients with an HVA under 37 degrees IMA and DMAA were mildly increased. The indication for distal osteotomy can be extended and algorithms can be simplified without sacrificing correction. Patients with an HVA of 37 degrees or more had a good correction in 65 percent, the remaining 35 percent developed recurrence of hallux valgus (7 percent of the overall group). Because inter- and intra-observer difference in measuring angles14 it might be better to use a cut-off range instead of cut-off point. Decisionmaking for extensive surgery can be preserved for young, high (cosmetic) demand patients. Future research needs to concentrate on patients with an HVA of 37 degrees and more, to clarify the optimal strategy to use open DSTP, correction of DMAA, Akin osteotomy, proximal osteotomy or a combination of these procedures. Conclusion The preoperative HVA is the main predictor for correction of hallux valgus. Correction rate declined in patients with HVA exceeding 37 degrees, caused by subluxation of the MTPJ. IMA and DMAA did not significantly predict possible correction rate, however, these parameters likely do contribute in preoperative HVA of 37 degrees or more. 55 CHAPTER 5 References 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 56 Antrobus, J. N.: The primary deformity in hallux valgus and metatarsus primus varus. Clin Orthop Relat Res, (184): 251-5, 1984. Austin, D. W., and Leventen, E. O.: A new osteotomy for hallux valgus: a horizontally directed “V” displacement osteotomy of the metatarsal head for hallux valgus and primus varus. Clin Orthop Relat Res, (157): 25-30, 1981. Button, G., and Pinney, S.: A meta-analysis of outcome rating scales in foot and ankle surgery: is there a valid, reliable, and responsive system? Foot Ankle Int, 25(8): 521-5, 2004. Chi, T. D.; Davitt, J.; Younger, A.; Holt, S.; and Sangeorzan, B. J.: Intra- and inter-observer reliability of the distal metatarsal articular angle in adult hallux valgus. Foot Ankle Int, 23(8): 722-6, 2002. Coughlin, M. J., and Freund, E.: Roger A. Mann Award. The reliability of angular measurements in hallux valgus deformities. Foot Ankle Int, 22(5): 369-79, 2001. Deenik, A. R.; Pilot, P.; Brandt, S. E.; van Mameren, H.; Geesink, R. G. T.; and Draijer, W. F.: Scarf versus Chevron osteotomy in hallux valgus. A randomised controlled trial in 96 patients. Foot Ankle Int, 28(5): 537-541, 2007. Faber, F. W.; Mulder, P. G.; and Verhaar, J. A.: Role of first ray hypermobility in the outcome of the Hohmann and the Lapidus procedure. A prospective, randomized trial involving one hundred and one feet. J Bone Joint Surg Am, 86-A(3): 486-95, 2004. Kitaoka, H. B.; Alexander, I. J.; Adelaar, R. S.; Nunley, J. A.; Myerson, M. S.; and Sanders, M.: Clinical rating systems for the ankle-hindfoot, midfoot, hallux, and lesser toes. Foot Ankle Int, 15(7): 349-53, 1994. Mann, R. A.: Decision-making in bunion surgery. Instr Course Lect, 39: 3-13, 1990. Mann, R. A., and Coughlin, M. J.: Hallux valgus--etiology, anatomy, treatment and surgical considerations. Clin Orthop Relat Res, (157): 31-41, 1981. Petje, G.; Steinbock, G.; and Schiller, C.: Radiographic analysis of metatarsus primus varus. 45 feet followed 15 months after distal metatarsal osteotomy and lateral soft-tissue release. Acta Orthop Scand, 68(6): 567-70, 1997. Resch, S.: Hallux valgus. Acta Orthop Scand, 67(1): 84-90, 1996. Robinson, A. H., and Limbers, J. P.: Modern concepts in the treatment of hallux valgus. J Bone Joint Surg Br, 87(8): 1038-45, 2005. Schneider, W.; Csepan, R.; Kasparek, M.; Pinggera, O.; and Knahr, K.: Intra- and interobserver repeatability of radiographic measurements in hallux surgery: improvement and validation of a method. Acta Orthop Scand, 73(6): 670-3, 2002. Schneider, W.; Csepan, R.; and Knahr, K.: Reproducibility of the radiographic metatarsophalangeal angle in hallux surgery. J Bone Joint Surg Am, 85-A(3): 494-9, 2003. SooHoo, N. F.; Shuler, M.; and Fleming, L. L.: Evaluation of the validity of the AOFAS Clinical Rating Systems by correlation to the SF-36. Foot Ankle Int, 24(1): 50-5, 2003. Stephens, M. M.: Pathogenesis of hallux valgus. Eur J Foot Ankle Surg, 1(1): 7-10, 1994. CHAPTER 6 Evidence of treatment algorithms for hallux valgus Axel Deenik, Aart Verburg, Jan-Willem Louwerens, Maarten de Waal Malefijt, Rob de Bie. Submitted 57 CHAPTER 6 Abstract Background: Algorithms have been developed to aid in the decision process in order to choose an optimal surgical procedure for different types of hallux valgus. These algorithms are evaluated in this study with current level 1 and 2 studies. Materials and Methods: Criteria for typing hallux valgus and surgical procedures in the treatment algorithms as proposed by Coughlin and Robinson were categorized. PubMed searches were performed to obtain data regarding preoperative parameters and outcome of surgical procedures. Gathered data were used to assess validity of algorithms as well as the validity of factors used in preoperative planning of hallux valgus surgery and proposed advantages of specific surgical techniques. Results: The PubMed search on preoperative criteria resulted in 97 references; four were classified as level 1 or 2 evidence. The PubMed search of surgical procedures resulted in 33 references of which seventeen were classified as level 1 or 2 evidence. Outcome was determined by severity of hallux valgus angle. The advantages of the certain procedures as advised in the algorithms to correct specific hallux valgus deformities have not been established in controlled clinical studies. Conclusion: Widely accepted flow-charts for the treatment of hallux valgus are not based on level 1 and 2 studies. Hallux valgus angle is found to be the single significant parameter for prediction of the surgical outcome. Correction declines with HVA exceeding 36 degrees, in these cases outcome of osteotomy becomes more uncertain. Keywords: review, hallux valgus, algorithm 58 SYSTEMATIC REVIEW Introduction Different types of hallux valgus have been described and categorized with associated flowcharts. These types are categorized as mild, moderate, and severe hallux valgus, first metatarsophalangeal (MTP) congruency, and tarsometatarsal (TMT) hypermobility. Correction is advised using specific matching procedures; however, flowcharts differ, they are derived from a historical experience based perspective and data are often based on level 3 evidence. In defining hallux valgus types opinions vary on whether the intermetatarsal angle (IMA), the hallux valgus angle (HVA), or both should be used as parameters for determining the severity of hallux valgus.17 Controversy exists whether TMT hypermobility requires treatment by TMT arthrodesis,31 whereas others have found that a first metatarsal osteotomy can suffice.13,14 Another topic of discussion is the optimal treatment strategy for severe hallux valgus.44 Some authors favour a proximal procedure,8 while others propagate a distal osteotomy.40,42,51 Algorithms should be supported by the findings from current level 1 and 2 studies. Purposes of this review are to assess the validity of factors presently used in preoperative planning of hallux valgus surgery and to examine whether proposed specific surgical procedures prove to do better in outcome. Materials and Methods Factors in preoperative planning The following factors used in preoperative planning were extracted from the reviews of Robinson and Coughlin to distinguish among different types of hallux valgus: severity of hallux valgus, first metatarsophalangeal (MTP) joint congruency, and TMT instability (Table 1).9,48 References for these parameters and matching procedures were included. A systematic literature search in PubMed was performed using the MeSH terms ‘hallux valgus surgery’ and ‘algorithm’ or ‘distal metatarsal articular angle’ (DMAA) or ‘hypermobility,’ covering the years 1966 through 2013. Trials using this search strategy were selected when two authors (AD and AV) agreed on the level of evidence.49 All level 1 and 2 studies in preoperative planning were selected. 59 CHAPTER 6 Table 1. Criteria for classification of hallux valgus types Coughlin Robinson Mild HVA<30; IMA<13 IMA<14 Moderate HVA<40; IMA>13 14>IMA>20 Severe HVA>40; IMA>20 IMA>20 TMT instability Yes Yes Congruent Yes Yes Surgical procedures The surgical procedures for corresponding deformities were extracted from the reviews of Robinson and Coughlin and are organized in Table 2.9,48 To verify parameters on this subject, a PubMed search was performed from 1966 till 2013 on the MeSH terms ‘hallux valgus osteotomy’ and ‘randomized controlled trial’. All randomized controlled trials were selected for this review when two authors (AD and AV) agreed on the level of evidence. Given that existing guidelines consistently lack support from level 1 and 2 studies, additional cohort studies were added by author AD and verified by author AV. Cohort studies were only included when radiographic outcome parameters HVA, recurrences and hallux varus were available. Table 2. Surgical procedures matched for correction of hallux valgus types Mild Coughlin Robinson chevron, Mitchell, or proximal osteotomy * chevron* Moderate Mitchell or proximal osteotomy* scarf* Severe proximal osteotomy, MTP fusion* scarf, proximal osteotomy, TMT fusion* TMT instability Lapidus (=TMT fusion) * Lapidus* Congruent biplane chevron scarf *Incongruent hallux valgus combined with a distal soft-tissue procedure Results Factors in preoperative planning With the PubMed search on ‘hallux valgus surgery’ and (‘algorithm’ or ‘DMAA’ or ‘first ray hypermobility’), 97 articles were found. Four articles relevant in preoperative planning provided level 1 or 2 evidence.17, 22, 28, 54 Additional evidence is categorized according to the mentioned classification criteria of hallux valgus. Hallux valgus severity: HVA and IMA are advised as markers of hallux valgus severity (level 3)15. Correlation between HVA and IMA was early recognized (level 3).25,24 Robin60 SYSTEMATIC REVIEW son states that “hallux valgus severity is commonly classified in a traditional way according to radiological criteria” (level 4).48 Metatarsus primus varus has a higher incidence in patients with hallux valgus compared to a normal control group (level 2).27 The IMA is commonly used to determine the desired amount of translation. Mann introduced IMA as a tool for hallux valgus severity (level 3)36 after observation of limitations in correction with the McBride procedure of hallux valgus with HVA exceeding 30 degrees.35, 22 In an analysis of preoperative factors (level 3),1 however, HVA was identified as the only significant factor in surgical correction. This conclusion is supported by a regression analysis of different preoperative factors, HVA was found to be the single significant parameter for prediction of surgical outcome. Outcome declined when the HVA exceeded 36 degrees (level 2).17 In using cut-off points, errors of measurement on radiographs of three degrees should be taken into account.54 Congruency: Piggott classified groups into ‘congruous’ and ‘subluxated.’ In a 6.5-year follow-up study, he concluded that congruent joints with hallux valgus did not progress significantly (level 4).43 DMAA was introduced as a radiological marker to decide which surgical correction is necessary.11 The clinical value of DMAA, however, in preoperative planning might be limited because of high interobserver differences.6,47 If on radiograph increased DMAA is suspected, obtaining an interoperative view of the MTP joint is commonly advised. First ray mobility: Lapidus introduced hypermobility of the first TMT joint as a causative factor in hallux valgus development (level 4).38,28 TMT hypermobility can be measured with the Klaue device (level 2),28 although this is clinically difficult to apply.21 Quantification of TMT hypermobility with manual examination is subjective and not reliable.38 A cadaver study showed that first ray mobility reduced after correction with proximal osteotomy combined with DSTP (level 3).14 Lesser MTP joint pathology, posterior tibial tendon dysfunction and medial arch degeneration are examples of a other factors that might influence surgical strategy in hallux valgus in order to restore anatomy, however, they are not used in algorithms. In an anatomic study the influence of the abductor hallucis on medial arch was established (level 3). General joint laxity is discussed as a factor that might influence surgical strategy in hallux valgus (level 3).5 There is evidence that patient expectations differ from those of orthopaedic surgeons (level 3).57 These patient expectations are not met in foot scores.56 61 CHAPTER 6 Surgical procedures The PubMed search on the MeSH terms ‘hallux valgus osteotomy’ and ‘randomized controlled trial’ resulted in 33 references, 16 were classified as level 1 and 2 evidence.4,16,18,19,20,21,23,26,29,30,4,32,40,41,52,59,60 Correction osteotomy is an effective treatment for painful hallux valgus compared to non operative treatment (level 1).18,59 A mathematical model showed that proximal procedures allow for more translation (level 1).30 These advantages have not been validated in randomized controlled trials (level 2).16,20 An earlier Cochrane review comparing surgical procedures for correction of hallux valgus failed to show superiority of any technique.22 Three randomized controlled trials did not show differences in correction (level 2).19,29,52 Additional evidence is categorized according to the mentioned classification criteria of hallux valgus (table 3). Different procedures achieve adequate correction; in 4 to 17% of cases, recurrence or hallux varus occurs. After use of the Lapidus procedure, hallux varus or recurrence was reported in 12% of cases.50,8 After MTP fusion, the average HVA was 20 degrees.12 The specific complication of non-union occurred in ten percent. The total of alignment complications, recurrences, hallux varus, and reoperations, was roughly between five and ten percent in all studies. Mild hallux valgus: Mann found good results with the McBride procedure, however, outcome declined in patients with HVA exceeding 30 degrees.22,35 Distal osteotomy is the most propagated alternative. Klossoc and Saro compared two distal procedures and found no clinical differences between both groups (level 1).29,52 Either osteotomy or a soft-tissue procedure can provide adequate correction for mild hallux valgus (level 3).2 Moderate hallux valgus: A more proximal procedure was advised in cases where HVA is 30 degrees or more (level 3).37 Other reports suggest that distal osteotomy can provide adequate correction with HVA under 36 degrees (level 2)17 or in patients with metatarsus primus varus (level 2)42 Forty percent of patients have a HVA within these 6 degrees of angular difference.17 Severe hallux valgus: A mathematical model showed that proximal procedures allow for more translation than distal procedures (level 1).30 However, in randomized controlled trials the correction of HVA or IMA on radiographs is equal between more proximal and distal procedures (level 2).16,20, The overall complication rate was comparable in these randomized controlled trials,16, 19, 20 however, specific complications did occur more frequently in proximal procedures. These complications concern plantair flexion in Lapidus procedure,20 rotational malunion and CRPS after the scarf osteotomy.7,16 62 SYSTEMATIC REVIEW Table 3: Outcome of surgical procedures for correction of hallux valgus Study Author 20 Faber Park Osteotomy 41 56 distal Schneider 63 Torkki shaft Kristen Trnka proximal Sammarco Easley Zettl lapidus (30 64 19 67 51 Distal soft tissue procedure Akin Recurrence hallux varus Hallux valgus angle Standard deviation Range Hohmann no no 4% 2% 9.9 8 NA Lapidus open no 2% 6% 13.3 10.4 NA distal chevron open 10.7 % none 2% 12.9 7.2 NA proximal chevron open 9.3 % 2% 4% 12.2 6.9 NA chevron open no 1% yes 13.5 NA -10 tot 40 chevron through joint no 7.5% no 17.9 NA 2 tot 42 scarf part* part 6% NA 13.4 NA 5 to 42 ludloff yes NA 4.5% 8 9 NA -14 to 32 chevron through joint no 4% 1% 17 NA -3 to 30 chevron open no 5% 12% 12.6 NA NA crescentic open no 5% 10% 10.1 NA NA crescentic open no 1%# 9% 14.6 14.6 -40 to 46 open no 8% 4% 11 NA -3 to 30 Lapidus open partial 5%# NA 16 3.1 NA MTP fusion no 20.4 NA 5-35 Sangeorzan Lapidus 52 Coetzee 8 MTP fusion Coughlin 12 no 14% nonunion 0 * only if 15 varus not able; # defined as revised cases; NA: Not Applicable Congruency: Osseous correction should be obtained extra-articular in case of a congruent hallux valgus,10 the scarf osteotomy is popularized because it is flexible in redressing DMAA. In case of a non-congruent hallux valgus a distal soft-tissue procedure is necessary to obtain a congruent joint. Bock observed more severe cartilage lesions during surgery with increasing hallux valgus severity.3 However, hallux valgus severity was not correlated with symptomatic osteoarthritis.55 First ray hypermobility: The Lapidus procedure was popularized as treatment for first ray hypermobility, being also one of the atavistic factors causing hallux valgus by Hansen (level 3).50 Coughlin found that first ray mobility reduced after performing proximal osteotomy combined with DSTP (level 2).13 Faber performed a randomized controlled trial comparing the results of the Lapidus procedure and a distal osteotomy (level 2).20 In a subgroup in which first ray hypermobility was identified, no differences were found in 63 CHAPTER 6 correction. The Lapidus procedure was reported to be appropriate in addressing remaining malalignment of the first metatarsal in hallux valgus.58 Distal soft-tissue procedure (DSTP) is advised to correct lateral contracture. A distal softtissue performed in addition to a chevron osteotomy did show a significant improvement in correction, however, no difference in patient’s satisfaction.46 The outcome of DSTP can be unpredictable, possibly because limited evidence is available concerning which structures need to be released (level 3).33,53 A randomized controlled trial between a first web-space versus transarticular approach for correction of moderate to severe hallux valgus did not show differences (level 2). New developments focus on improving early mobilization, which is supported by lowprofile plates or compression screw fixation. Calder showed that patients with screw fixation of a Mitchell osteotomy did recover earlier in comparison to those after suture fixation (level 2).4 Percutaneous procedures have been developed to minimize soft tissue trauma, and Magnan found lower complication rates and less surgery time using this type of corrective surgery (level 3).34 One RCT of 20 patients between percutaneous osteotomy and scarf osteotomy showed similar correction and outcome (level 3).23 Discussion Evidence for widely accepted flow-charts are not based on level 1 and 2 studies. The advantages of the different procedures to correct specific deformities have not been established in controlled clinical studies. It seems valid to distinguish different types of hallux valgus in preoperative planning. However, there is limited evidence of differences in outcome between the currently used subtypes. The HVA was found to be the single significant parameter for prediction of the surgical outcome, because the outcome declined when the HVA exceeded 36 degrees. It is accepted that successful correction of hallux valgus consists of balancing the soft tissues around the MTP joint and aligning the great toe and first metatarsal. Overall good outcome is achieved with distal, shaft or proximal metatarsal osteotomy, fusion of the MTP joint or TMT joint, all can address several types of hallux valgus. The theoretical advantage in correction of proximal procedures in comparison to distal ones has not been established in clinical studies.16,20,39,45,40 Differences in correction between a proximal and a distal osteotomy are possibly less than assumed. Patients might be treated with more extensive procedures than required.16 64 SYSTEMATIC REVIEW Controversy exists whether TMT instability should be judged as a cause or an effect of hallux valgus deformity. TMT fusion and DSTP is proposed as single procedure to treat TMT instability, although decrease of TMT instability and good outcome have been obtained in proximal osteotomy with DSTP.13 This finding suggests that extrinsic anatomical features play a role in first ray mobility. Instability might be addressed through reduction of the metatarsal head within the plantar plate and corresponding structures, which results in stability of the MTP and TMT joints. Different opinions exist in cases where correction might be difficult to maintain, like patients with severe hallux valgus or revision cases.44 One RCT showed similar results between distal and proximal osteotomy in severe hallux valgus.40 In some cases fusion of the MTP or TMT joint may be more effective. Outcome might be influenced by uncommon types of hallux valgus or related foot problems like lesser MTP joint pathology, posterior tibial tendon dysfunction and medial arch insufficiency, degenerative flatfoot, adductus forefoot, the patients age, neuromuscular disorders and arthritic diseases.61 These items might be recognized and a focus for a new algorithm, which would still be limited to an experienced based algorithm, because to base such an algorithm on EBM will be even more difficult to achieve. Selection bias was limited by agreement upon 2 authors (AD and AV) on presentation of all level 1 and 2 studies. Selection bias possibly did occur with including level 3 studies, however, level 3 studies will not influence the conclusion that limited evidence is available for current treatment algorithms. Conclusion The present used treatment algorithms for hallux valgus surgery are primarily based on expert opinion and are not supported by level 1 and 2 studies. Neither is the possible advantage of specific surgical procedures based on controlled clinical studies. Correction osteotomy is more effective than nonoperative treatment in patients with hallux valgus. Many operative techniques are adequate in achieving a good outcome. The HVA was found to be the single predictive parameter and correction declines with a HVA exceeding 36 degrees. 65 CHAPTER 6 References 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 66 Antrobus, J. N.: The primary deformity in hallux valgus and metatarsus primus varus. Clin Orthop Relat Res, (184): 251-5, 1984. Austin, D. W., and Leventen, E. O.: A new osteotomy for hallux valgus: a horizontally directed “V” displacement osteotomy of the metatarsal head for hallux valgus and primus varus. Clin Orthop Relat Res, (157): 25-30, 1981. Bock, P.; Kristen, K. H.; Kroner, A.; and Engel, A.: Hallux valgus and cartilage degeneration in the first metatarsophalangeal joint. J Bone Joint Surg Br, 86(5): 669-73, 2004. Calder, J. D.; Hollingdale, J. P.; and Pearse, M. F.: Screw versus suture fixation of Mitchell’s osteotomy. A prospective, randomised study. J Bone Joint Surg Br, 81(4): 621-4, 1999. Carl, A.; Ross, S.; Evanski, P.; and Waugh, T.: Hypermobility in hallux valgus. Foot Ankle, 8(5): 264-70, 1988. Chi, T. D.; Davitt, J.; Younger, A.; Holt, S.; and Sangeorzan, B. J.: Intra- and inter-observer reliability of the distal metatarsal articular angle in adult hallux valgus. Foot Ankle Int, 23(8): 722-6, 2002. Coetzee, J. C.: Scarf osteotomy for hallux valgus repair: the dark side. Foot Ankle Int, 24(1): 29-33, 2003. Coetzee, J. C., and Wickum, D.: The Lapidus procedure: a prospective cohort outcome study. Foot Ankle Int, 25(8): 526-31, 2004. Coughlin, M. J.: Hallux valgus. Instr Course Lect, 46: 357-91, 1997. Coughlin, M. J.: Hallux valgus in men: effect of the distal metatarsal articular angle on hallux valgus correction. Foot Ankle Int, 18(8): 463-70, 1997. Coughlin, M. J.: Roger A. Mann Award. Juvenile hallux valgus: etiology and treatment. Foot Ankle Int, 16(11): 682-97, 1995. Coughlin, M. J.; Grebing, B. R.; and Jones, C. P.: Arthrodesis of the first metatarsophalangeal joint for idiopathic hallux valgus: intermediate results. Foot Ankle Int, 26(10): 783-92, 2005. Coughlin, M. J., and Jones, C. P.: Hallux valgus and first ray mobility. A prospective study. J Bone Joint Surg Am, 89(9): 1887-98, 2007. Coughlin, M. J.; Jones, C. P.; Viladot, R.; Glano, P.; Grebing, B. R.; Kennedy, M. J.; Shurnas, P. S.; and Alvarez, F.: Hallux valgus and first ray mobility: a cadaveric study. Foot Ankle Int, 25(8): 537-44, 2004. Coughlin, M. J.; Mann, R. A.; and Saltzman, C. L.: Surgery of the foot and ankle. Edited, 184-362, Mosby Inc., 2007. Deenik, A.; van Mameren, H.; de Visser, E.; de Waal Malefijt, M.; Draijer, F.; and de Bie, R.: Equivalent correction in scarf and chevron osteotomy in moderate and severe hallux valgus: a randomized controlled trial. Foot Ankle Int, 29(12): 1209-15, 2008. Deenik, A. R.; de Visser, E.; Louwerens, J. W.; de Waal Malefijt, M.; Draijer, F. F.; and de Bie, R. A.: Hallux valgus angle as main predictor for correction of hallux valgus. BMC Musculoskelet Disord, 9: 70, 2008. Deenik, A. R.; Pilot, P.; Brandt, S. E.; van Mameren, H.; Geesink, R. G.; and Draijer, W. F.: Scarf versus chevron osteotomy in hallux valgus: a randomized controlled trial in 96 patients. Foot Ankle Int, 28(5): 537-41, 2007. Easley, M. E.; Kiebzak, G. M.; Davis, W. H.; and Anderson, R. B.: Prospective, randomized comparison of proximal crescentic and proximal chevron osteotomies for correction of hallux valgus deformity. Foot Ankle Int, 17(6): 307-16, 1996. Faber, F. W.; Mulder, P. G.; and Verhaar, J. A.: Role of first ray hypermobility in the outcome of the Hohmann and the Lapidus procedure. A prospective, randomized trial involving one hundred and one feet. J Bone Joint Surg Am, 86-A(3): 486-95, 2004. Faber, F. W.; van Kampen, P. M.; and Bloembergen, M. W.: Long-term results of the Hohmann and Lapidus procedure for the correction of hallux valgus: a prospective, randomised trial with eight- to 11-year followup involving 101 feet. Bone Joint J, 95-B(9): 1222-6, 2013. Ferrari, J.; Higgins, J. P.; and Prior, T. D.: Interventions for treating hallux valgus (abductovalgus) and bunions. Cochrane Database Syst Rev, (1): CD000964, 2004. Giannini, S.; Cavallo, M.; Faldini, C.; Luciani, D.; and Vannini, F.: The SERI distal metatarsal osteotomy and Scarf osteotomy provide similar correction of hallux valgus. Clin Orthop Relat Res, 471(7): 2305-11. SYSTEMATIC REVIEW 24. Hardy, R. H., and Clapham, J. C.: Hallux valgus; predisposing anatomical causes. Lancet, 1(24): 1180-3, 1952. 25. Hardy, R. H., and Clapham, J. C.: Observations on hallux valgus; based on a controlled series. J Bone Joint Surg Br, 33-B(3): 376-91, 1951. 26. Jones, K. J.; Feiwell, L. A.; Freedman, E. L.; and Cracchiolo, A., 3rd: The effect of chevron osteotomy with lateral capsular release on the blood supply to the first metatarsal head. J Bone Joint Surg Am, 77(2): 197204, 1995. 27. Kilmartin, T. E.; Barrington, R. L.; and Wallace, W. A.: Metatarsus primus varus. A statistical study. J Bone Joint Surg Br, 73(6): 937-40, 1991. 28. Klaue, K.; Hansen, S. T.; and Masquelet, A. C.: Clinical, quantitative assessment of first tarsometatarsal mobility in the sagittal plane and its relation to hallux valgus deformity. Foot Ankle Int, 15(1): 9-13, 1994. 29. Klosok, J. K.; Pring, D. J.; Jessop, J. H.; and Maffulli, N.: Chevron or Wilson metatarsal osteotomy for hallux valgus. A prospective randomised trial. J Bone Joint Surg Br, 75(5): 825-9, 1993. 30. Kummer, F. J.: Mathematical analysis of first metatarsal osteotomies. Foot Ankle, 9(6): 281-9, 1989. 31. Lapidus, P. W.: A quarter of a century of experience with the operative correction of the metatarsus varus primus in hallux valgus. Bull Hosp Joint Dis, 17(2): 404-21, 1956. 32. Lechler, P.; Feldmann, C.; Kock, F. X.; Schaumburger, J.; Grifka, J.; and Handel, M.: Clinical outcome after Chevron-Akin double osteotomy versus isolated Chevron procedure: a prospective matched group analysis. Arch Orthop Trauma Surg, 132(1): 9-13, 2012. 33. Lin, I.; Bonar, S. K.; Anderson, R. B.; and Davis, W. H.: Distal soft tissue release using direct and indirect approaches: an anatomic study. Foot Ankle Int, 17(8): 458-63, 1996. 34. Magnan, B.; Bortolazzi, R.; Samaila, E.; Pezze, L.; Rossi, N.; and Bartolozzi, P.: Percutaneous distal metatarsal osteotomy for correction of hallux valgus. Surgical technique. J Bone Joint Surg Am, 88 Suppl 1 Pt 1: 135-48, 2006. 35. Mann, R. A.: Decision-making in bunion surgery. Instr Course Lect, 39: 3-13, 1990. 36. Mann, R. A.: Distal soft tissue procedure and proximal metatarsal osteotomy for correction of hallux valgus deformity. Orthopedics, 13(9): 1013-8, 1990. 37. Mann, R. A., and Pfeffinger, L.: Hallux valgus repair. DuVries modified McBride procedure. Clin Orthop Relat Res, (272): 213-8, 1991. 38. Myerson, M. S., and Badekas, A.: Hypermobility of the first ray. Foot Ankle Clin, 5(3): 469-84, 2000. 39. Park, H. W.; Lee, K. B.; Chung, J. Y.; and Kim, M. S.: Comparison of outcomes between proximal and distal chevron osteotomy, both with supplementary lateral soft-tissue release, for severe hallux valgus deformity: A prospective randomised controlled trial. Bone Joint J, 95(4): 510-6, 2013. 40. Park, Y. B.; Lee, K. B.; Kim, S. K.; Seon, J. K.; and Lee, Y.K.: Comparison of distal soft-tissue procedures combined with a distal chevron osteotomy for moderate to severe hallux valgus: first web-space versus transarticular approach. Bone Joint J, 95-B(5): 649-56, 2013. 41. Park, Y. B.; Lee, K. B.; Kim, S. K.; Seon, J. K.; and Lee, J. Y.: Comparison of distal soft-tissue procedures combined with a distal chevron osteotomy for moderate to severe hallux valgus: first web-space versus transarticular approach. J Bone Joint Surg Am, 95(21): e158, 2013. 42. Petje, G.; Steinbock, G.; and Schiller, C.: Radiographic analysis of metatarsus primus varus. 45 feet followed 15 months after distal metatarsal osteotomy and lateral soft-tissue release. Acta Orthop Scand, 68(6): 567-70, 1997. 43. Piggot, H.: The Natural history of hallux valgus in adolescence and early adult life. J Bone Joint Surg Br, 42B(4): 749-760, 1960. 44. Pinney, S. J.; Song, K. R.; and Chou, L. B.: Surgical treatment of severe hallux valgus: the state of practice among academic foot and ankle surgeons. Foot Ankle Int, 27(12): 1024-9, 2006. 45. Resch, S.; Stenstrom, A.; Jonsson, K.; and Reynisson, K.: Results after chevron osteotomy and proximal osteotomy for hallux valgus: a prospective, randomized study. the Foot, 3: 99-104, 1993. 46. Resch, S.; Stenstrom, A.; Reynisson, K.; and Jonsson, K.: Chevron osteotomy for hallux valgus not improved by additional adductor tenotomy. A prospective, randomized study of 84 patients. Acta Orthop Scand, 65(5): 541-4, 1994. 67 CHAPTER 6 47. Robinson, A. H.; Cullen, N. P.; Chhaya, N. C.; Sri-Ram, K.; and Lynch, A.: Variation of the distal metatarsal articular angle with axial rotation and inclination of the first metatarsal. Foot Ankle Int, 27(12): 1036-40, 2006. 48. Robinson, A. H., and Limbers, J. P.: Modern concepts in the treatment of hallux valgus. J Bone Joint Surg Br, 87(8): 1038-45, 2005. 49. Sackett, D.: Evidence-based medicine. Lancet, 346(8983): 1171, 1995. 50. Sangeorzan, B. J., and Hansen, S. T., Jr.: Modified Lapidus procedure for hallux valgus. Foot Ankle, 9(6): 262-6, 1989. 51. Sanhudo, J. A.: Correction of moderate to severe hallux valgus deformity by a modified chevron shaft osteotomy. Foot Ankle Int, 27(8): 581-5, 2006. 52. Saro, C.; Andren, B.; Wildemyr, Z.; and Fellander-Tsai, L.: Outcome after distal metatarsal osteotomy for hallux valgus: a prospective randomized controlled trial of two methods. Foot Ankle Int, 28(7): 778-87, 2007. 53. Schneider, W.: Influence of different anatomical structures on distal soft tissue procedure in hallux valgus surgery. Foot Ankle Int, 33(11): 991-6, 2012. 54. Schneider, W.; Csepan, R.; Kasparek, M.; Pinggera, O.; and Knahr, K.: Intra- and interobserver repeatability of radiographic measurements in hallux surgery: improvement and validation of a method. Acta Orthop Scand, 73(6): 670-3, 2002. 55. Schneider, W.; Csepan, R.; and Knahr, K.: Reproducibility of the radiographic metatarsophalangeal angle in hallux surgery. J Bone Joint Surg Am, 85-A(3): 494-9, 2003. 56. Schneider, W., and Knahr, K.: Surgery for hallux valgus. The expectations of patients and surgeons. Int Orthop, 25(6): 382-5, 2001. 57. Tai, C. C.; Ridgeway, S.; Ramachandran, M.; Ng, V. A.; Devic, N.; and Singh, D.: Patient expectations for hallux valgus surgery. J Orthop Surg (Hong Kong), 16(1): 91-5, 2008. 58. Taylor, N. G., and Metcalfe, S. A.: A review of surgical outcomes of the Lapidus procedure for treatment of hallux abductovalgus and degenerative joint disease of the first MCJ. Foot (Edinb), 18(4): 206-10, 2008. 59. Torkki, M.; Malmivaara, A.; Seitsalo, S.; Hoikka, V.; Laippala, P.; and Paavolainen, P.: Hallux valgus: immediate operation versus 1 year of waiting with or without orthoses: a randomized controlled trial of 209 patients. Acta Orthop Scand, 74(2): 209-15, 2003. 60. Windhagen, H.; Radtke, K.; Weizbauer, A.; Diekmann, J.; Noll, Y.; Kreimeyer, U.; Schavan, R.; StukenborgColsman, C.; and Waizy, H.: Biodegradable magnesium-based screw clinically equivalent to titanium screw in hallux valgus surgery: short term results of the first prospective, randomized, controlled clinical pilot study. Biomed Eng Online, 12: 62, 2013. 61. Wülker, N., and Mittag, F.: The treatment of hallux valgus. Dtsch Arztebl Int, 109(49): 857-67, 2012. 68 CHAPTER 7 Validity of hallux valgus angle measurement using plantar pressure measurement: A pilot study Axel Deenik, Nick Guldemond, Peter Pilot, Geert Walenkamp, Aart Verburg, Rob de Bie. Submitted 69 CHAPTER 7 Abstract Background: Hallux valgus is a common foot problem in women. Outcome of surgical correction is described with the aid of clinical improvement rates, radiographic measurements and electronic pressure sensitive platforms. This study was conducted to compare the hallux valgus angle (HVA) between radiographic and electronic measurements. Materials and Methods: After informed consent twenty patients were included. Bunionectomy, osteotomy and capsulorraphy were performed in all patients. Data were collected with AOFAS questionnaires, preoperative and postoperative radiographs and electronic pressure sensitive (EMED) platforms in all patients. Measurements on radiographs and EMED data were compared. Results: EMED HVA data were consistently lower than X-ray HVA data in the same patient and consistently showed lower standard deviations. In 75 percent of the cases a positive correlation was found, but also a systematic difference occurred between X-ray and EMED HVA data. Conclusion: EMED hallux valgus angle assessments can be useful to monitor changes in the individual patient. It might not be an alternative to radiographic hallux valgus measurements since systematic differences in HVAs occur. 70 ANGLE MEASUREMENT WITH EMED Introduction Hallux valgus occurs with progressive lateral deviation of the hallux and medial deviation of the first metatarsal bone.3 When adjustment of footwear fails to decrease pain from a bunion, surgical correction is possibly indicated. Decisions for surgical planning are made on clinical judgments and grading severity from static radiographs.4 In preoperative planning the main parameter is the hallux valgus angle (HVA) as assessed on radiographs.6 Hallux valgus angle can also be measured by electronic pressure sensitive platforms. Electronic pressure sensitive platforms (EPSP) are used to quantify static and dynamic foot function both in research and in clinical settings.11 Plantar pressure data provide information on the magnitude and location of pressures exerted on the sole of the foot. In research settings Novel software (Novel, Munich) is commonly used for foot pressure measurements. One of the embedded software options is hallux angle measurement. The angle is calculated from the pressure profile of the foot. For the plantar pressure measurements biomechanical data, without X-ray irradiation is used. EPSP measurements are studied in hallux valgus surgery to be able to correlate pressure findings with clinical improvement.1 However, the concurrent validity with standard HVA measurements from radiographs has not yet been determined. The objective of this study is to determine the validity of EPSP and correlate EPSP values with the hallux valgus angle obtained from standing posterior-anterior (PA) radiographs. Patients and Methods Twenty consecutive patients were included in a prospective study. All patients were seen preoperatively, three months postoperatively and finally when a normal walking pattern was established. Clinical data were collected consisting AOFAS scores,9 EMED data and X-rays. Patients were included when they presented with a painful bunion and hallux valgus, were between 18 and 65 years of age and had an adequate range of movement. Patients were excluded if they presented with rheumatoid arthritis, had undergone a previous hallux valgus surgery and showed symptomatic and/or radiological osteoarthritis of the metatarsophalangeal joint (MTPJ).8 All patients suited for inclusion were asked to participate in the study all patients received oral and written study information and provided informed consent preceding the surgical procedure. Pre- and postoperative data were collected in all cases. The study was approved by the medical ethics committee of the Maaslandziekenhuis, Sittard, the Netherlands. 71 CHAPTER 7 Radiological data Radiological evaluation was performed according to standardized procedures. Standing X-rays were made pre- and postoperative. One examiner (ARD) evaluated the weight bearing PA X-rays. On the X-rays the hallux valgus angle (HVA) was measured in which the HVA was defined as the angle between the line from the center of the metatarsal base to the center of the first metatarsal head and the line connecting the midpoints of the proximal and distal articular surfaces of the proximal phalanx.10 Plantar pressure data Plantar pressure measurements were recorded using the EMED SF-4 Pedography Analyzer, Novel gmbh, Munich (Germany). A capacitive pressure platform is centred flush within a horizontal walkway. Ten measurements were taken with the participant walking barefoot using the two-step method.2 Data were collected preoperatively and folluw-up measurement took place when the participant was able to attain a normal walking pattern after operation in the University Hospital Maastricht, the Netherlands: The pre- and postoperative data were averaged in a ‘clinical report’, after which the average hallux angle and the SDs were analyzed. Analysis This study was designed to assess feasibility of pressure measurements in clinical practice. Hallux valgus angles obtained from X-rays and pressure measurements were recorded. Differences were calculated. Data of individual patients were plotted in a diagram. AOFAS score was only recorded to verify for possible clinical confounders. Results The participants consisted of 6 men and 14 women with a mean age of 48 years (range 21-65). Mean follow-up period was 9 months (range 7-13 months). All patients were surgically corrected because of symptoms related to their hallux valgus deformity. Twelve patients received a Chevron osteotomy, seven patients a Scarf osteotomy and one patient underwent a modified McBride procedure. Radiological and EPSP acquired angles and clinical outcome are shown in table 1. Together with clinical improvement the AOFAS score increased from 44 to 88 points. Surgical procedures showed comparable results despite different procedures. One complication was found in the patient that received a McBride procedure because of recurrence of the hallux valgus deformity. However, pain importantly decreased because of removal of the bunion. 72 ANGLE MEASUREMENT WITH EMED Table 1 Hallux valgus angle measured on EMED foot pressure and X-rays Preoperative mean Preoperative SD Postoperative mean Postoperative SD D Mean HVA x-ray 31.8 7.8 18.5 8.2 13.3 HVA EMED 18.3 5.4 11.6 6.4 Δ Mean 13.5 6.9 6.7 6.4 AOFAS Score 48 13.8 88 12.1 Pain 15 10.2 36 6.6 Function 31 6.9 39 5.1 Alignment 1 2.6 13 4.1 EMED HVA data are consistently lower than X-ray HVA data in the same patient (table 1). EMED data consistently show a lower standard deviation. The difference in HVA obtained by EMED was plotted against difference in HVA obtained by X-ray (figure 1). The diagram showed that there is no systematic trend in the differences between both methods of measurements. However, in 75% of the measured angles between pressure measurement and radiographic measurement a positive correlation was found. In 19 cases a reduction of the HVA was measured after surgery in the radiological and the EMED group. In 1 case the same HVA was measured after surgery both with X-ray and EMED.12 Figure 1 Pre- and Post-operative measures 73 CHAPTER 7 Discussion The objective of this pilot study was to determine the validity of the EMED hallux valgus angle measurement in comparison to standard PA radiographs. Achieved correction differed between both methods, however, a positive correlation was found in 75 % of the cases between both measurements. The direction of change in hallux valgus angle after surgery was equal with both methods, however EMED HVA showed consistently lower values. Radiological measurement of hallux valgus is the gold standard. The intraobserver measurement accuracy of this method is 2.1 degrees 12 In all but one cases reduction of the HVA was established after surgery In one case the same HVA was measured before and after surgery with X-ray and EMED measurements. The EMED hallux valgus angle can be useful in research settings for study of progression of hallux valgus in an individual patient. In preoperative planning the hallux valgus angle remains the main parameter.6 Besides, pedographic analysis might in a clinical setting be too time consuming for clinical practice. Data were collected by the two-step method, which is a reliable method of obtaining data.9 The data acquired by EPSP are dynamic in nature while radiological measurements are static. This difference in measurement technique and data acquisition might also account for the observed differences between X-ray and EMED assessments. Yet, in research settings it is interesting to know of hallux valgus condition is primarily symptomatic in a dynamic biomechanical situation, and mimics walking behavior and ADL function, while X-ray assessments remain static and thus have no bearing on ADL. Clinical improvement according to AOFAS scores of performed procedures was according to the literature. 7,5 Therefore, we assume that the surgical procedures cannot be seen as a confounder in this study. Recent studies in larger cohorts support earlier findings in lateralization of pressure in the foot after surgery.13,15 However, hallux valgus angle in pressure measurements in those studies are not reported. Data were collected to monitor clinical recovery in comparison to pedographic and radiographic correction. Pedographic analysis is used in assessing metatarsalgia.14 In our study group no cases had clinical metatarsalgia. The differences in pressure and radiographic patterns are variable.1 Our group of twenty patients is too small for comparison of pressure patterns. The EMED hallux measurements show lower standard deviations, which differ from the standard deviations in radiographic measurements. Because angular changes in the 74 ANGLE MEASUREMENT WITH EMED individual patient were measured accurately after surgical correction, a possible application of EMED can be to monitor angle differences in individual patient. Conclusion EMED hallux valgus angle can be useful to monitor changes in the individual patient. In preoperative planning use of the EMED angle the confidence level seems limited in comparison to radiographic hallux valgus angle measurements. 75 CHAPTER 7 References 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 76 Brodsky, J. W.; Beischer, A. D.; Robinson, A. H.; Westra, S.; Negrine, J. P.; and Shabat, S.: Surgery for hallux valgus with proximal crescentic osteotomy causes variable postoperative pressure patterns. Clin Orthop Relat Res, 443: 280-6, 2006. Bryant, A.; Singer, K.; and Tinley, P.: Comparison of the reliability of plantar pressure measurements using the two-step and midgait methods of data collection. Foot Ankle Int, 20(10): 646-50, 1999. Coughlin, M. J.; Mann, R. A.; and Saltzman, C. L.: Surgery of the foot and ankle. Edited, 184-362, Mosby Inc., 2007. Coughlin, M. J.; Saltzman, C. L.; and Nunley, J. A., 2nd: Angular measurements in the evaluation of hallux valgus deformities: a report of the ad hoc committee of the American Orthopaedic Foot & Ankle Society on angular measurements. Foot Ankle Int, 23(1): 68-74, 2002. Deenik, A.; van Mameren, H.; de Visser, E.; de Waal Malefijt, M.; Draijer, F.; and de Bie, R.: Equivalent correction in scarf and chevron osteotomy in moderate and severe hallux valgus: a randomized controlled trial. Foot Ankle Int, 29(12): 1209-15, 2008. Deenik, A. R.; de Visser, E.; Louwerens, J. W.; de Waal Malefijt, M.; Draijer, F. F.; and de Bie, R. A.: Hallux valgus angle as main predictor for correction of hallux valgus. BMC Musculoskelet Disord, 9: 70, 2008. Deenik, A. R.; Pilot, P.; Brandt, S. E.; van Mameren, H.; Geesink, R. G.; and Draijer, W. F.: Scarf versus chevron osteotomy in hallux valgus: a randomized controlled trial in 96 patients. Foot Ankle Int, 28(5): 537-41, 2007. Hattrup, S. J., and Johnson, K. A.: Subjective results of hallux rigidus following treatment with cheilectomy. Clin Orthop Relat Res, (226): 182-91, 1988. Kitaoka, H. B.; Alexander, I. J.; Adelaar, R. S.; Nunley, J. A.; Myerson, M. S.; and Sanders, M.: Clinical rating systems for the ankle-hindfoot, midfoot, hallux, and lesser toes. Foot Ankle Int, 15(7): 349-53, 1994. Miller, J. W.: Distal first metatarsal displacement osteotomy. Its place in the schema of bunion surgery. J Bone Joint Surg Am, 56(5): 923-31, 1974. Orlin, M. N., and McPoil, T. G.: Plantar pressure assessment. Phys Ther, 80(4): 399-409, 2000. Schneider, W.; Csepan, R.; and Knahr, K.: Reproducibility of the radiographic metatarsophalangeal angle in hallux surgery. J Bone Joint Surg Am, 85-A(3): 494-9, 2003. Schuh, R.; Adams, S.; Hofstaetter, S. G.; Krismer, M.; and Trnka, H. J.: Plantar loading after chevron osteotomy combined with postoperative physical therapy. Foot Ankle Int, 31(11): 980-6, 2010. Waldecker, U.: Metatarsalgia in hallux valgus deformity: a pedographic analysis. J Foot Ankle Surg, 41(5): 300-8, 2002. Wen, J.; Ding, Q.; Yu, Z.; Sun, W.; Wang, Q.; and Wei, K.: Adaptive changes of foot pressure in hallux valgus patients. Gait Posture, 108(1) 1447-56, 2012. CHAPTER 8 General discussion 77 GENERAL DISCUSSION This chapter summarizes the findings of this thesis. First, the outcome of different studies is presented according to preoperative planning and surgical procedures. Second, our findings are discussed along with possible shortcomings of our study. Third, new findings from our research are categorized in recommendations for clinical practice. Fourth, the patient perspective is added. The discussion ends with possible future directions for practice and research. Findings from this thesis For preoperative planning purposes this thesis showed in chapter 4 that favourable outcome decreases with increasing IMA. In chapter 6, we showed that the HVA is the significant predictor for correction of hallux valgus. Severe HV can be defined by HVA larger than 37 degrees, outcome of surgery declined with a recurrence rate of 35 percent in this group. IMA and DMAA did not significantly predict possible correction rate. In chapter 6, we confirmed that different types of hallux valgus exist. Importance of TMT hypermobility in preoperative planning is controversial. In chapter 7, we showed that pressure measurements are not a reliable alternative to measuring HVA in preoperative planning. Concerning differences in surgical procedures this thesis showed in chapter 3, no differences in correction between chevron (a stable, versatile distal procedure) and scarf (a stable versatile shaft procedure). Chapter 5 showed no advantages in correction in moderate and severe hallux valgus with use of a shaft osteotomy. Chapter 6, we showed that not one technique is superior over the other for correction of hallux valgus. Validity of our findings Preoperative planning The use of HVA in preoperative planning takes place according to established guidelines.4 Our study confirmed that HVA is the significant parameter to predict outcome of hallux valgus surgery. A cut-off point of 37 degrees is in agreement with existing guidelines,4 and it its cut-off has been validated based on data from a large cohort study.6 In our data IMA is not significant in predicting radiologic outcome.6 However, influence of IMA can be explained because HVA and IMA are correlated.21 IMA can help to visualize the widening of the first metatarsal and might clinically be considered in an IMA over 17 degrees.21 Inter-observer differences in IMA measurements have more impact in classification of types of hallux valgus. DMAA was not significant in preoperative planning in our calculations. This is expected because earlier reports showed measurement of the 79 CHAPTER 8 DMAA is inaccurate,20,3 although this does not exclude the importance of the direction of the articular surface in correction procedures. Surgical procedures Shaft (more proximal) procedures did not result in a better radiographic or clinical outcome than distal corrections in hallux valgus procedures. Our findings are consistent with other randomized controlled trials.9,8 However, based on a mathematical model, proximal procedures theoretically allow for more translation (level 1 evidence) of the distal fragment.13 Proximal procedures do offer a higher amount of possible correction. Our surgical protocol may have been insufficient to detect possible relevant differences. One RCT showed similar results between distal and proximal osteotomy in severe hallux valgus.17 Our literature search showed that recurrences occur in all correction procedures. However, recurrence rates are difficult to compare, since no uniform definition of recurrence is available. A precise definition of recurrence as an endpoint would make comparison of surgical procedures more reliable. Recommendations for clinical practice Mann and Coughlin introduced grading of different hallux valgus types to operate these types with corresponding procedures.23 Improvements in surgical techniques have been introduced to achieve better correction and increase stability of osteotomies. However, recurrence of deformities occurs in general in 10 percent of the patients treated for hallux valgus. Factors like osteoarthritis, tight achilles tendon, posterior tibial tendon rupture that might influence outcome and therefore change a treatment plan should be recognised. Consequences of hallux valgus surgery, potential improvements and possible disadvantages should be discussed and used to adjust patient expectations. Preoperative planning The HVA measured on AP radiographs should be used in preoperative planning. An HVA under 37 degrees can be used to classify mild cases. In acquired hallux valgus without other foot pathology, it is likely that the geometry of other joints than the metatarsophalangeal remained unchanged, although this should be verified on clinical examination. These patients comprise 75 percent of the overall group of hallux valgus cases. In patients with an HVA of around 35 degrees, there might be uncertainty whether the deformity should be classified as mild or severe. Inter- and intra-observer variability of at 80 GENERAL DISCUSSION least 3 degrees should be taken into account when using a cut-off point.23 Especially in mild deformities one should be aware of symptomatic instead of cosmetic motives, because possible complications like pain or stiffness might be less accepted. Severe hallux valgus can be classified as cases with HVA over 37 degrees. Metatarsophalangeal (sub)luxation does progress as a consequence of an increasing hallux valgus deformity and might lead to articular degeneration and soft-tissue contracture in time. Increase of a hallux valgus deformity is an unfavourable prognostic factor for surgical outcome. When hallux valgus deformity exceeds a certain point, around 37 degrees, it promotes biomechanical changes outside the metatarsaphalangeal and tarsometatarsal joints. It is difficult to quantify changes exceeding the first ray, because each foot consists of 28 bones and 33 joints, a complex interplay occurs in which osseous anatomy is disturbed together with balance of intrinsic and extrinsic foot musculature. Contracture of soft-tissues might influence surgical strategies as well. The extent to which a hallux valgus deformity can be reduced might help to obtain an impression about the tightness of the adductor hallucis and lateral capsule. Pronation of the hallux is correlated to shortening of the adductor hallucis. Increase of pressure on the lesser metatarsals and lesser (II-IV) metatarsophalangeal joint instability adds to the severity of forefoot pathology. Besides biomechanical changes, the absence of osteoarthritis of MTPJ should be verified with clinical and radiographic examination in planning correction osteotomy. In patients with hallux valgus with radiologically normal MTPJ, the grade of cartilage lesions was correlated with hallux valgus angle.1 Other factors are not directly correlated to hallux severity, however, might need attention in a preoperative treatment plan, like a predisposing tight Achilles tendon, pes planus with or without hyperlaxity, and neuromuscular disorders. Especially patients with prior osteotomy, shortening of the first ray should be assessed. Surgical treatment In mild cases, biomechanical changes probably are limited to the first metatarsal joint and hallux. With correction of the first ray one can achieve anatomical reconstruction. A standard procedure is preferable with a limited number of steps and a limited soft-tissue dissection, in order to decrease swelling and reduce possible chance of complications. Distal osteotomies require a less extensive exposure and shorter operation time, which results in shorter recovery time.7 In mild cases a good outcome is more easily obtained; however, an undercorrection might be less accepted. Recent reports of percu81 CHAPTER 8 taneous procedures are encouraging. Possible advantages are lower complication rates and less operative time. The possible disadvantage is lack of osseous compression. 11,15,2 One RCT of 20 patients between percutaneous osteotomy and scarf osteotomy showed similar correction and outcome (level 3).10 A recent systematic review showed that the data are insufficient to promote systematic use of less invasive procedures.14 In moderate hallux valgus the deformity can be amplified by soft-tissue imbalance. In order to achieve a durable correction an open adductor release seems indicated. With distal osteotomy generally good correction can be achieved.19 Because there are limitations to the amount of translation that can be achieved, a proximal osteotomy seems a viable alternative. A proximal procedure offers the opportunity of a larger translation of the distal fragment, with the disadvantage of increased swelling and more complications.7,5 This is a consequence of a wider wound exposure with more surgical steps. In severe hallux valgus the controversy of treatment is underlined in a hypothetical case where different distal and proximal osteotomy, MTP fusion and lapidus procedures were proposed by different surgeons.18 Preoperative planning in this patient group might be more experience-based than evidence-based. One third of the patients will develop a recurrence after distal osteotomy. Again, a proximal osteotomy seems favourable in osseous correction, although recurrence and hallux varus do occur in all types of osteotomy. Extensive release of soft-tissues should result in sustainable ligament balance. Fusion is a good alternative procedure, if ligamentous balance might be too difficult to achieve. MTP fusion will solve the soft-tissue contracture in the MTP joint with the downside that these patients lose motion in the MTP joint. TMT fusion will keep the first metatarsal in the corrected position, with the disadvantage of first ray shortening. Recurrence, hallux varus or osteoarthritis still can occur in the MTP joint. In preoperative planning, increase of corrective options by extensive procedures should be weighed against possible complications in the individual patient. Except for specific procedure-related complications, recurrence can be considered as the primary unsatisfactory outcome parameter, symptomatic osteoarthritis as a secondary one. A ten-year follow-up after Chevron osteotomy showed progression of osteoarthritis of the first MTPJ, although these patients did not suffer clinical consequences.22 Timing In mild hallux valgus surgical correction can be obtained with many procedures. However, patients with good outcome might be inclined to wear high-heeled shoes after surgery and compromise longterm outcome. Future shoe-wear should be discussed with the patient before operation. 82 GENERAL DISCUSSION As hallux valgus progresses over time, the biomechanic function of the foot deteriorates. Older people with disabling foot pain have a higher risk of a decrease in mobility or even falling.16 More extensive procedures are preferred to correct the biomechanical deformation, although longer recovery times and unfavourable outcome do occur more frequently. Timing of surgery is an important factor in the individual patient. However, we have no data if or when progression occurs. Therefore, the individual patient might be monitored as long as the deformity remains stable and symptoms can be reduced with shoewear. Surgery should be considered when progression occurs, preferably before a severely deformed foot develops. Personal preference Prevention of hallux valgus will be effective if the use of high-heeled shoes with a narrow toe-box is minimized. However, it is unlikely that general education programs about adequate shoes will have priority and the fashion industry will not have their priority on wear-ability, comfort or sensibility. Therefore, the orthopaedic surgeon has a task to educate the patient before discussing the option of corrective surgery. In younger patients I favour procedures that restore anatomy. Mild deformity is best corrected with a stable procedure with minimal soft tissue trauma. Compression screws and postoperative shoes both facilitate early mobilisation.12 Possible superiority of percutaneous procedures are not substantiated by current data.14 In severe hallux valgus a proximal crescentic osteotomy with temporary fixation of the TMT joint in younger patients theoretically enable larger correction, although distal procedures are still a viable alternative.17 In revision surgery or in cases with severely deformed feet MTP fusion is a predictable procedure with good outcome. In choosing timing and an optimal procedure, an inventory should be made of the patient’s expectations, activity and age of the patient, pain with and without shoes, forefoot insufficiency, importance of cosmetic appearance and desire to wear high-heeled shoes. In cases of alternative treatment options, specific advantages and disadvantages of indicated procedures should be discussed with the patient, in order to advise a solution tailored to individual needs. Because of lack of evidence, patients need to be informed, instead of leaving the decision to an algorithm. Generally, we can anticipate that surgical correction of the bunion generally results in distribution of pressure from the bunion to the medial side of the foot. Although cosmetic and biomechanical correction can be insufficient in individual cases, hallux valgus surgery is often successful in reduction of pain. 83 CHAPTER 8 References 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 84 Bock, P.; Kristen, K. H.; Kroner, A.; and Engel, A.: Hallux valgus and cartilage degeneration in the first metatarsophalangeal joint. J Bone Joint Surg Br, 86(5): 669-73, 2004. Calder, J. D.; Hollingdale, J. P.; and Pearse, M. F.: Screw versus suture fixation of Mitchell’s osteotomy. A prospective, randomised study. J Bone Joint Surg Br, 81(4): 621-4, 1999. Chi, T. D.; Davitt, J.; Younger, A.; Holt, S.; and Sangeorzan, B. J.: Intra- and inter-observer reliability of the distal metatarsal articular angle in adult hallux valgus. Foot Ankle Int, 23(8): 722-6, 2002. Coughlin, M. J.: Hallux valgus. J Bone Joint Surg Am, 78(6): 932-66, 1996. Deenik, A.; van Mameren, H.; de Visser, E.; de Waal Malefijt, M.; Draijer, F.; and de Bie, R.: Equivalent correction in scarf and chevron osteotomy in moderate and severe hallux valgus: a randomized controlled trial. Foot Ankle Int, 29(12): 1209-15, 2008. Deenik, A. R.; de Visser, E.; Louwerens, J. W.; de Waal Malefijt, M.; Draijer, F. F.; and de Bie, R. A.: Hallux valgus angle as main predictor for correction of hallux valgus. BMC Musculoskelet Disord, 9: 70, 2008. Deenik, A. R.; Pilot, P.; Brandt, S. E.; van Mameren, H.; Geesink, R. G.; and Draijer, W. F.: Scarf versus chevron osteotomy in hallux valgus: a randomized controlled trial in 96 patients. Foot Ankle Int, 28(5): 537-41, 2007. Deenik, A. R.; Pilot, P.; Brandt, S. E.; van Mameren, H.; Geesink, R. G. T.; and Draijer, W. F.: Scarf versus Chevron osteotomy in hallux valgus. A randomised controlled trial in 96 patients. Foot Ankle Int, 28(5): 537-541, 2007. Faber, F. W.; Mulder, P. G.; and Verhaar, J. A.: Role of first ray hypermobility in the outcome of the Hohmann and the Lapidus procedure. A prospective, randomized trial involving one hundred and one feet. J Bone Joint Surg Am, 86-A(3): 486-95, 2004. Giannini, S.; Cavallo, M.; Faldini, C.; Luciani, D.; and Vannini, F.: The SERI distal metatarsal osteotomy and Scarf osteotomy provide similar correction of hallux valgus. Clin Orthop Relat Res, 471(7): 2305-11. Holmes, G. B., Jr., and Hsu, A. R.: Correction of intermetatarsal angle in hallux valgus using small suture button device. Foot Ankle Int, 34(4): 543-9, 2013. Huang, S. H.; Cheng, Y. M.; Chen, C. H.; and Huang, P. J.: Modified Mitchell osteotomy with screw fixation for correction of hallux valgus. Foot Ankle Int, 33(12): 1098-102, 2012. Kummer, F. J.: Mathematical analysis of first metatarsal osteotomies. Foot Ankle, 9(6): 281-9, 1989. Maffulli, N.; Longo, U. G.; Marinozzi, A.; and Denaro, V.: Hallux valgus: effectiveness and safety of minimally invasive surgery. A systematic review. Br Med Bull, 97: 149-67, 2011. Magnan, B.; Bortolazzi, R.; Samaila, E.; Pezze, L.; Rossi, N.; and Bartolozzi, P.: Percutaneous distal metatarsal osteotomy for correction of hallux valgus. Surgical technique. J Bone Joint Surg Am, 88 Suppl 1 Pt 1: 135-48, 2006. Menz, H. B.; Morris, M. E.; and Lord, S. R.: Foot and ankle risk factors for falls in older people: a prospective study. J Gerontol A Biol Sci Med Sci, 61(8): 866-70, 2006. Park, H. W.; Lee, K. B.; Chung, J. Y.; and Kim, M. S.: Comparison of outcomes between proximal and distal chevron osteotomy, both with supplementary lateral soft-tissue release, for severe hallux valgus deformity: A prospective randomised controlled trial. Bone Joint J, 95-B(4): 510-6, 2013. Pinney, S. J.; Song, K. R.; and Chou, L. B.: Surgical treatment of severe hallux valgus: the state of practice among academic foot and ankle surgeons. Foot Ankle Int, 27(12): 1024-9, 2006. Potenza, V.; Caterini, R.; Farsetti, P.; Forconi, F.; Savarese, E.; Nicoletti, S.; and Ippolito, E.: Chevron osteotomy with lateral release and adductor tenotomy for hallux valgus. Foot Ankle Int, 30(6): 512-6, 2009. Robinson, A. H.; Cullen, N. P.; Chhaya, N. C.; Sri-Ram, K.; and Lynch, A.: Variation of the distal metatarsal articular angle with axial rotation and inclination of the first metatarsal. Foot Ankle Int, 27(12): 1036-40, 2006. Robinson, A. H., and Limbers, J. P.: Modern concepts in the treatment of hallux valgus. J Bone Joint Surg Br, 87(8): 1038-45, 2005. Schneider, W.; Aigner, N.; Pinggera, O.; and Knahr, K.: Chevron osteotomy in hallux valgus. Ten-year results of 112 cases. J Bone Joint Surg Br, 86(7): 1016-20, 2004. Schneider, W.; Csepan, R.; and Knahr, K.: Reproducibility of the radiographic metatarsophalangeal angle in hallux surgery. J Bone Joint Surg Am, 85-A(3): 494-9, 2003. CHAPTER 9 Summary Samenvatting (Summary in Dutch) 85 Summary Chapter 1 provides an introduction to this thesis which explaines that hallux valgus starts with cosmetic changes and might lead to a foot deformation. The characteristics of hallux valgus are described. Different surgical targets to correct different types of hallux valgus are discussed together with surgical benefits and limitations. This leads to our research aims concerning classification and surgical correction of hallux valgus. Chapter 2 reports on a retrospective review in which the influence of the intermetatarsal angle on outcome of surgery is studied. 21 patients (24 feet) with hallux valgus after performing a Hohmann osteotomy and compared the long-term results of feet with metatarsus primus varus (MPV) with those with normal intermetatarsal (IMT) angles. Three-quarter of the patients had good or excellent outcome. The clinical and radiological results of patients with MPV were worse than in the group with normal IMT angles. Hohmann osteotomy was a reliable procedure for patients with a normal IMT angle in MPV outcome declined. Chapter 3 reports on the results of a prospective randomized controlled trial between two surgical procedures to correct hallux valgus deformity (scarf versus chrevron osteotomies). The purpose of this study is to evaluate if one of the techniques results in a better correction of the IMA and HVA. 96 cases in 83 consecutive patients were treated and follow-up was 2 years. After 2 years follow-up no differences of statistical significance could be measured between both groups with respect to the AOFAS score, HVA and IMA. Both groups showed good to excellent results, however, the chevron osteotomy is technically less demanding. Chapter 4 reports on the results of a prospective randomized controlled trial between scarf and chevron osteotomy in moderate and severe hallux valgus.136 feet in 115 consecutive patients were treated and follow-up was 2 years. Deformities of patients were classified as mild, moderate and severe according to IMA flowcharts. The results were compared in the different subgroupes using radiographic HVA, IMA and distal metatarsal articular angle (DMAA) measurements. In patients with moderate and severe hallux valgus the outcome of scarf and chevron osteotomy do not differ. Chapter 5 reports on the influence of radiographic parameters on the postoperative hallux valgus angle. 136 feet in 115 patients were included. Bunionectomy, osteotomy, lateralization of the distal fragment, lateral release and medial capsulorraphy were performed in all patients. Data were collected on preoperative and postoperative HVA, IMA 87 CHAPTER 9 and DMAA measurements. Logistic regression was performed on data. Preoperative HVA was the single significant parameter for prediction of postoperative HVA in logistic regression. Correction rate declined from preoperative HVA of 37. Chapter 6 reports on the validity of factors used in preoperative planning of hallux valgus and surgical procedures proposed in algorithms. Preoperative factors and matching procedures were extracted from articles of Robinson and Coughlin. A systematic search was performed in order to evaluate different factors and surgical procedures. Selected articles were classified according to level of evidence. The search on preoperative criteria resulted in 100 references; four were classified as level 2 evidence. The search on surgical procedures resulted in 52 references of which ten were classified as level 1 or 2 evidence. Widely accepted flow-charts for the treatment of hallux valgus are not based on level 1 and 2 studies. Hallux valgus angle is found to be the single significant parameter for prediction of the surgical outcome. Possible superiority of a technique was not substantiated by data. Chapter 7 reports on the validity of the hallux valgus angle calculated from electronically measured foot pressures in comparison to radiographic measurements. Twenty cases in twenty patients were included. Bunionectomy, osteotomy and capsulorraphy were performed in all patients. Data were collected with AOFAS questionnaires, preoperative and postoperative radiographs and electronic pressure sensitive platforms (EMED) all patients. Measurements on radiographs and EMED data were compared. EMED data are consistently lower than X-ray data in the same patient. EMED data consistently show a lower range of distribution. EMED hallux valgus angle was reliable to monitor changes in the individual patient. As alternative to radiographic hallux valgus measurements the confidence level seems limited. Chapter 8 presents the overall findings of this thesis. The clinical outcome is presented and the validity of our findings is discussed. Recommendations for clinical practice are summarized. In lack of evidence, this thesis is concluded with a personal view. In lack of evidence based algorithms the alternative to inform patients about timing and type of surgery is posed. Samenvatting 88 Samenvatting In hoofdstuk 1 wordt een inleiding gegeven over de ontwikkeling van scheefstand van de grote teen, hallux valgus, en het belang van de aandoening. De scheefstand van de grote teen bestrijkt een breed klinisch spectrum startend met een milde scheefstand zonder symptomen en mogelijk eindigend met een ernstige voetmisvorming. De kenmerken die, zoals beschreven in de wetenschappelijke literatuur, gebruikt worden om verschillende typen hallux valgus te onderscheiden worden beschreven. De verschillende chirurgische behandelingsopties die op basis van deze kenmerken worden geadviseerd worden vervolgens besproken. Ten slotte worden in dit hoofdstuk de onderzoeksvragen geformuleerd die hebben geleid tot de in dit proefschrift beschreven studies. Deze zijn gericht op het toetsen van de wetenschappelijk onderbouwing op basis waarvan de verschillende typen van hallux valgus zijn opgesteld en op de onderbouwing van de aangegeven voordelen van chirurgische behandelingsstrategieën. In hoofdstuk 2 hebben we retrospectief de invloed van de intermetatarsale hoek op de uitkomst van de Hohmann correctie osteotomie bij patiënten met hallux valgus onderzocht. Bij 21 patiënten (24 voeten) met hallux valgus werden de lange termijn resultaten van een Hohmann correctie osteotomie vergeleken van patiënten met metarsus primus varus (MPV) en patiënten met normale intermetatarsale (IMT) hoeken. Vijfenzeventig procent van de patiënten had een goed tot uitstekend resultaat. De klinische en radiologische resultaten van patiënten met normale IMT waren beter dan patiënten met MPV. Hohmann osteotomie bleek een betrouwbare procedure voor correctie van patiënten met hallux valgus met een normale IMT, bij MPV werd de uitkomst minder. In hoofdstuk 3 hebben we een prospectief gerandomiseerde studie beschreven tussen 2 chirurgische technieken, scarf versus chevron osteotomie, om hallux valgus te corrigeren. Het doel van de studie is te beoordelen of één van de technieken leidt tot een betere correctie van de hallux valgus hoek (HVA) en intermetatarsale hoek (IMA). 96 voeten bij 83 achtereenvolgende patiënten werden gegeïncludeerd, en de follow-up bedroep 2 jaar. Na 2 jaar follow-up konden geen statische significante verschillen tussen beide groepen gevonden worden met betrekking tot AOFAS score, HVA en IMA. Beide groepen toonden goed tot uitstekende resultaten. De chevron osteotomie werd technisch eenvoudiger gevonden. In hoofdstuk 4 beschrijven we de resultaten van een prospectief gerandomiseerde studie tussen scarf en chevron osteotomie in matige en forse hallux valgus. 135 voeten bij 115 achtereenvolgende patiënten werden behandeld, de follow-up bedroeg 2 jaar. Volgens 89 CHAPTER 9 classificatiecriteria van Coughlin, werden patiënten geclassificeerd als mild, matig of ernstige hallux valgus. De resultaten werden vergeleken in de subgroepen volgens radiologische criteria. In patiënten met matig of ernstige hallux valgus waren de resultaten tussen scarf en chevron osteotomie gelijk. In hoofdstuk 5 hebben we de invloed onderzocht van radiologische parameters op de postoperatieve hallux valgus hoek (HVA). 136 voeten in 115 patiënten werden geïncludeerd. Bunionectomie, osteotomie, laterale verschuiving van het distale fragment, laterale release werd verricht in alle patiënten. HVA, IMA and DMAA werden pre- en postoperatief gemeten volgens gestandaardiseerde meetmethoden. In een regressieanalyse bleek de preoperatieve HVA de enige significante parameter voor de postoperatieve HVA. Radiologische resultaten werden minder bij een HVA van 37 of meer. In hoofdstuk 6 hebben we gezocht naar de wetenschappelijke onderbouwing voor factoren die in preoperatieve planning van hallux valgus gebruikt worden, en de chirurgische methoden die volgens algoritmen voorgesteld worden. Preoperatieve criteria en chirurgische procedures passende bij specifieke hallux valgus typen werden uit artikelen van Coughlin en Robinson geëxtraheerd. Een systematische zoekmethode werden deze criteria en operatie methoden geëvalueerd. Artikelen werden geselecteerd en onderverdeeld naar bewijskracht. De zoekmethode naar preoperatieve criteria gaf 100 referenties, waarvan 4 werden geclassificeerd als ‘level 1 en 2 evidence’. De zoekmethode naar chirurgische procedures leidde tot 52 resultaten, waarvan 10 werden geclassificeerd als level I/II. Hallux valgus hoek bleek de enige significante parameter met een voorspellende waarde t.a.v. chirurgisch resultaat. Geen van de chirurgische technieken bleek tot significant betere uitkomsten te leiden. In hoofdstuk 7 wordt de betrouwbaarheid van de hallux valgus hoek, berekent uit data van voetdrukmetingen, vergeleken met radiologische metingen. Twintig patiënten zijn geincludeerd. Bunionectomie osteotomie en weke delen release werd verricht in alle patiënten. AOFAS score, pre- en postoperatief röntgenfoto’s en voetdrukdata via (EMED) werd verkregen in alle patiënten. Radiologische en EMED data werden vergeleken. EMED berekende HVA zijn lager dan radiologisch verkregen HVA. EMED HVA bleek betrouwbaar in het meten van veranderingen in de individuele patiënt. In vergelijking tot radiologisch berekende HVA is de betrouwbaarheid te beperkt. In hoofdstuk 8 worden de belangrijkste bevindingen van het proefschrift beschreven. De hallux valgus hoek is de enige voorspellende parameter voor het resultaat van een operatie. Er kon geen verschil aangetoond worden tussen scarf en chevron osteotomie. Onderbouwing voor verdere aanscherping ontbreekt in de literatuur. 90 Valorisation of hallux valgus preoperative criteria and outcome 91 VALORISATION OF HALLUX VALGUS In addition to the scientific value of this thesis, described in chapters 2 – 7, the research results also have societal and economic consequences. This dissertation generated new knowledge in the field of preoperative criteria for hallux valgus surgery and outcome of recommended surgical procedures. In this part of my thesis I would like to explain the innovative aspect of the research and consequences for medical practice, discuss the findings in a social and economic context, discuss the population it concerns and propose approaches for further improvement into preoperative planning and surgery. Innovation Correction osteotomy is an effective treatment for painful hallux valgus compared to non operative treatment.1 Although good results are found in many studies, in some reports patient dissatisfaction remains high.2 A Cochrane review concluded that quality of studies was poor.3 In this thesis we were able to identify one important prognostic factor regarding surgical outcome. Correction results declined with a hallux valgus angle exceeding 37 degrees. The innovation is that the hallux valgus angle is a practical and easily assessed feature, which helps to improve prediction of positive surgical outcome. From the distinction of a mild/moderate or severe type of hallux valgus, in clinical practice one can choose whether a different of treatment should be considered. Innovation in surgical treatment of hallux valgus did not lie in the presentation of new techniques, but to test supposed advantages of shaft versus distal correction osteotomy. We could not find differences between both procedures, however, a higher percentage of chronic regional pain syndrome in the shaft osteotomy, possibly because it is a more extensive procedure. This finding might be discussed in ‘shared decision making’ between surgeons and patients, before deciding to perform a more extensive surgical procedure. Although our research concerns a large cohort of patients, we only studied two procedures out of 140 available surgical procedures. Therefore an additional literature search was performed, to check for other feasible treatment modalities. This study did not only concentrate on our surgical procedures, but also on other specific treatment modalities. These surgical procedures are used as a solution for a certain type of hallux valgus, however, these claims were opposed by other authors. In the end, no evidence about superiority of other relevant techniques was found. For direct patient care it therefore seems wise to be careful when correcting patients with HVA exceeding 37 degrees or more, to give sufficient information about differences of alternate treatment procedures to the patient, success rates to be expected, and to take other relevant factors such as rehabilitation, importance of mobility of the MTP 93 VALORISATION joint into account to provide the patient with the best possible information and expectancies regarding the outcome of the treatment procedure. Social and economic relevance The social and economic relevance of hallux valgus is difficult to calculate, given that it can be a progressive condition. In mild cases hallux valgus can be asymptomatic, but it might gradually lead to a painful biomechanically compromised foot. Progression of deformity and symptoms can aggravate in a relative short period of time in some patients, in other patients the disorder can be asymptomatic without progression. Change of confection shoe-wear in wider, flat shoes can be effective to ameliorate symptoms and is cost-effective in mild deformities, although shoe-wear nor orthotics do not cure mild or moderate hallux valgus.4 With increasing hallux valgus severity, conservative treatment is more likely to fail. However, surgical correction is a superior treatment modality for hallux valgus in comparison to orthoses.5 Severe hallux valgus with forefoot insufficiency can have a serious impact on quality of life.6 People with disabling foot pain risk a decrease in mobility and have an increased risk of falling. A meta-analysis has estimated the percentage of hallux valgus in adults to lie around 23% (and 36% in elderly people aged over 65 years).7 Therefore, it is important for elderly to have biomechanically a proper function of their feet. Primarily, this starts with prevention of hallux valgus. Younger females should be educated at the negative effect that high-heeled narrow shoes might have on feet. Secondary, regular follow-up of patients of hallux valgus can be important, specifically if progression occurs and these patients are not indicated for surgery yet. Thirdly, footscreening in the elderly might be considered. Correction surgery should be considered in case progression cannot be stopped. For the best possible outcome it seems favorable to perform surgery before severe hallux valgus can develop. Although surgical outcome generally is good, dissatisfaction in some reports remains high. Our study identified the hallux valgus angle as preoperative parameter to select patients with severe hallux valgus. It showed these patients still had favorable outcome, however, outcome declined in comparison to patients with mild and moderate hallux valgus. Our study showed that a distal osteotomy obtained similar results as shaft osteotomy. We do prefer a distal procedure, because the technique is more straightforward and less demanding. Extended procedures theoretically have better potential for correction of severe deformities, however, this has not been verified in clinical studies. 94 VALORISATION OF HALLUX VALGUS Increased awareness of these issues among clinicians might help to ensure that the burden of HVA remains within parameters of normal foot functionality prevents further deterioration and therewith can ensure a reasonable quality of life in current and new patients. Population it concerns The target group concerns patients with hallux valgus indicated for surgery. The estimated prevalence of hallux valgus is 23 percent in the general population. One out of a thousand patients consults the general practitioner annually with a painful hallux valgus. 90 percent of these patients concern women, mainly because of the influence of highheels on this multifactorial condition. In 80 percent pain is the most important complaint, in which it limits normal walking function and hampers the use of normal footwear. In 2012, according to ‘Opendisdata’ 4548 patients were operated for hallux valgus. Opendisdata is an open access website, which contains data of diagnoses registered by physicians in Dutch hospitals, 85 % was completed in 2012. In this dissertation it is described that patients with a hallux valgus angle exceeding 36 degrees have an increased chance of unsuccessful outcome. This subgroup concerns about 10 percent of the patients indicated for surgery. These patients can expect from correction surgery a reduction of pain and a better ability to wear shoes. In part of the patients the deformity is not completely corrected, therefore, biomechanical long-term consequences are not known. If anatomical alignment cannot be achieved, a recurrence is likely to be expected over time, with possible consequences on biomechanical function. Articles are written about forefoot insufficiency and increased risk of falling.7 No data are available whether hallux valgus surgery prevents forefoot insufficiency. No data are available which percentage of conservative or surgical treated patients are hampered by long-term forefoot insufficiency, nor a possible preventive effect from surgical procedures. Future research Future research can be divided in preoperative criteria and surgical procedures. The HVA is significant parameter in preoperative planning regarding surgical outcome, however, the underlying biomechanical and anatomical mechanisms are poorly translated in preoperative surgical schemes. Adequate realignment is a requirement; however, it is no guarantee for long-term correction. In mild to moderate hallux valgus the deformity is 95 VALORISATION likely limited to the MTP joint and after adequate correction ligament balance likely is restored. In severe hallux valgus, the deformity likely extends to nearby lying structures and it is uncertain whether a surgical procedure with a good realignment results in longterm correction. Research regarding surgical outcome should be divided between mild to moderate and severe cases of hallux valgus. In 90 percent of the patients, the cases with mild to moderate hallux valgus, good results can be obtained. Because surgical outcome is quite good, it is difficult to gain enough power to measure a positive effect of the technique used. Future improvement can be gained primarily from prevention of surgical flaws or methods. Further improvement is to be expected from fine-tuning surgical procedures that minimize soft-tissue trauma and increase stability and postoperative rehabilitation. In patients with severe hallux valgus the investigated surgical procedures showed in part of the cases insufficient correction. Although technically there is more improvement to gain, it is questionable whether these patients would benefit from a surgical protocol. Because only 10 percent of the patients with hallux valgus can be classified as severe, it seems not feasible in future studies to gain enough power for this specific research group to reach statistical significance. Moreover, with progression of hallux valgus the group becomes more heterogeneous, because the deformity can extend to the forefoot, TMT joint, the cartilage of the MTP joint and further. In these cases the approach might be experience based, underlying biomechanical and anatomical mechanisms should be understood and addressed in order to improve outcome. To measure outcome, it might be preferred to have a national registry for patients with severe hallux valgus. According to ‘opendis’ data (measured in 2012) 10.301 cases with hallux valgus were registered as hallux valgus. If we assume that 10 % can be classified as severe, 1000 consultations might be classified as severe. 4548 cases were operated for hallux valgus, the estimated subgroup with severe hallux valgus should therefore lie around 450 patients. Additional criteria to grade hallux valgus severity should include forefoot insufficiency, MTP subluxation or dislocation, cartilage defects in the MTP joint. When the hallux valgus angle exceeds 37 degrees conservative and surgical treated patients should be included, preferably linked with Patient Related Outcome Scores. This database could provide information about possible future surgical events in the conservative and surgical treated patient group. Real improvement can be achieved when a model is available to classify feet as biomechanically compromised Of longitudinal follow-up it would be interesting to try to quantify the influence of shoe-wear on possible progression. 96 VALORISATION OF HALLUX VALGUS Conclusion The HVA was found to be the single predictive parameter and correction declines with a HVA exceeding 36 degrees. The present used treatment algorithms for hallux valgus surgery are primarily based on expert opinion and are not supported by level 1 and 2 studies. Correction osteotomy is more effective than non-operative treatment in patients with hallux valgus. Possible advantages of specific surgical procedures have not been established in controlled clinical studies. Many operative techniques are adequate to achieve good outcome. Because severe hallux valgus with forefoot insufficiency can have a serious impact on quality of life and falling it is an important subject for further research. 97 VALORISATION References 1. Torkki M, Malmivaara A, Seitsalo S, Hoikka V, Laippala P, Paavolainen P. Hallux valgus: immediate operation versus 1 year of waiting with or without orthoses: a randomized controlled trial of 209 patients. Acta Orthop Scand 2003;74-2:209-15. 2. Ferrari J. Bunions. Clin Evid (Online) 2009. 3. Ferrari J, Higgins JP, Prior TD. Interventions for treating hallux valgus (abductovalgus) and bunions. Cochrane Database Syst Rev 2004-1:CD000964. 4. Reina M, Lafuente G, Munuera PV. Effect of custom-made foot orthoses in female hallux valgus after oneyear follow up. Prosthet Orthot Int. 5. Torkki M, Malmivaara A, Seitsalo S, Hoikka V, Laippala P, Paavolainen P. Surgery vs orthosis vs watchful waiting for hallux valgus: a randomized controlled trial. Jama 2001;285-19:2474-80. 6. Menz, H. B.; Morris, M. E.; and Lord, S. R.: Foot and ankle risk factors for falls in older people: a pro-spective study. J Gerontol A Biol Sci Med Sci, 61(8): 866-70, 2006. 7. Nix SE, Vicenzino BT, Collins NJ, Smith MD. Characteristics of foot structure and footwear associated with hallux valgus: a systematic review. Osteoarthritis Cartilage;20-10:1059-74. 8. Mickle KJ, Munro BJ, Lord SR, Menz HB, Steele JR. ISB Clinical Biomechanics Award 2009: toe weakness and deformity increase the risk of falls in older people. Clin Biomech (Bristol, Avon) 2009;24-10:787-91. 98 Dankwoord 99 DANKWOORD Een proefschrift kan alleen tot stand komen met de hulp van anderen. Veel collega's, ondersteunend personeel en vrienden ben ik dank verschuldigd voor hun directe of indirecte bijdrage of luisterend oor. Ik heb me moeten beperken en wil hier beginnen mijn dank te betuigen aan de secretaresses in het Bronovo en andere ziekenhuizen voor de logistieke ondersteuning en aan ieder die hier niet genoemd wordt. Ten aanzien van klinieken gaat mijn bijzondere dank uit naar de Maatschap Orthopedie Sittard en de vakgroep orthopedie van het Radboudumc voor de stimulerende omgeving van werken en wetenschap in een warme sfeer met ook ruimte voor humor. Maar zeker ook naar de ruimte en steun binnen opleidingcluster Zuid én de assistentengroep om de follow-up van het grote cohort te continueren. De volgende personen wil ik in het bijzonder bedanken: Prof. R.A. de Bie. Beste Rob, je gaf voldoende ruimte om data uit te werken, met een kader waar binnen dat plaats diende te vinden en feedback om de boodschap te verwoorden. Je praktische invulling, humor en steun in de rug waar nodig hebben mij een fijn gevoel over het traject gegeven. Je coachende rol is voor mij een voorbeeld. Drs. F. Draijer. Beste Frits. Een man een man, een woord een woord. Dank voor je trouwe en nauwkeurige manier van werken en ondersteuning in het onderzoek. Je nieuwsgierigheid en je dilemma hoe uitkomsten geïntegreerd moeten worden met je persoonlijke ervaring voor optimale patiëntenzorg heb ik gewaardeerd. Dr. A.D. Verburg. Beste Aart, dank je voor je snelle correctie van teksten. Je hebt de bijzondere gave om, bijvoorbeeld bij revisie chirurgie, moeilijke zaken eenvoudig te maken (op andere vakken soms ook omgekeerd). Je opgeruimde houding, inzet en kennis overdracht zonder persoonlijk gewin maken je tot een bijzondere opleider. Dr. J.W. Louwerens. Beste Jan-Willem, dank je dat je ondanks je drukke klinische en bestuurlijke werkzaamheden tijd kon vinden voor feedback. Je advies heeft me goed geholpen om stellingen ten aanzien van onder andere beslisbomen en evidence neutraler te verwoorden. Dr. M. De Waal Malefijt. Beste Maarten, dank voor je fijne feedback gericht op het verwoorden van de boodschap en het oordeel van een potentiële reviewer in plaats van tekstueel na te kijken bij nog rammelende opzet. Drs. H. van Os. Beste Hans, mijn dank dat je met Frits en Aart mij de ondersteuning gegeven hebt dit onderzoek in Sittard te ontwikkelen samen met de start om mij tot orthopedisch chirurg te ontwikkelen. De open communicatie waarbij ieder betrokken wordt in het proces van patiëntenzorg heb ik gewaardeerd. Dr. P. Pilot. Beste Peter, dank je voor je drijvende kracht voor conscentiëuze inclusie en controle op het naleven van het protocol van de studie. Je inzet binnen je functie is een belangrijke factor voor de continuïteit van deze en vele andere studies in Sittard geweest. 101 DANKWOORD Drs. E. Brandt. Beste Erwin, dank voor je voortgang samen met Peter in de prille (en kwetsbare) fase van het onderzoek en je precieze behandeling van patiënten. Prof. H. van Mameren. Beste Henk, dank voor onze anatomie sessies die een andere toegang en blik op hallux valgus gegeven hebben gelardeerd met humor en relativerende opmerkingen over operaties. Tevens dank dat je me in contact gebracht hebt met Rob de Bie. Dr. E. de Visser. Beste Rico, dank voor je snelle redigeerwerk, humor en gave om lastige zaken luchtig te maken. Prof. G.H. Walenkamp. Beste Geert, dank voor het exploreren van mogelijkheden om de RCT uit te breiden, en je hulp en kennis bij voetdrukmetingen en je opmerkingen op me scherp op de inhoud te houden. Prof. N. Guldemond. Beste Nick, dank voor je hulp op meerdere vakken bij het lastige hoofdstuk voetdrukmeting. Dr. G.H.R. Albers. Beste Rob, dank je voor de introductie in het vak en de eerste wetenschappelijke stappen op dit onderwerp en praktische feedback. Prof. dr. R. Geesink. Beste Ruud, dank voor de ruimte mij te ontwikkelen tot orthopedisch chirurg en de ruimte tot onderzoek in het Academisch Ziekenhuis Maastricht. Je ontspannen houding en tolerantie vind ik bijzonder. Ewoud Witkamp en Vincent Steenmeijer. Beste maten, wetenschap heeft in het algemeen niet de grootste prioriteit in een perifeer ziekenhuis. Dank voor jullie begrip om dit boekje af te ronden. Ik waardeer en ben er trots op dat in onze vakgroep de nadruk op kwaliteit en patiëntenzorg ligt. Naast dank voor de directe hulp bij het tot standkomen van het boekje, ben ik minstens zo dankbaar voor de onvoorwaardelijke steun van familie en vrienden. Paranymfen Elvira en Marc, ik verheug me met jullie aanwezigheid en steun de openbare verdediging te doen en er een mooie dag van de maken. Elvira Tijdens-Creusen. Beste Elvira, dank je wel voor je vriendschap, je collegialiteit met humor en charme. Daarbij waardeer ik de spiegel die je op verzoek voorhoudt met de benodigde nuance. Ik ben blij met je feedback om me voor de laatste loodjes op scherp te zetten. Marc Eecen. Beste Marc, dank voor je vriendschap. Ik waardeer je vermogen verschillende onderwerpen tot de juiste proportie terug te brengen of in juiste context te plaatsen, vaak met een relativerend grap. Het lijkt me geweldig om met je de Sahara in een jeep te doorkruisen. Jan Duijff. Beste Jan, dank je voor de vele fietskilometers, zeker in het buitenland. De verhouding in gesprekken tussen ons vak, de natuur, wetenschap en het leven gedurende onze fietstochten zal mogelijk iets anders komen te liggen. Ik hoop van harte dat we nog een Trans Alp samen gaan mountainbiken. 102 DANKWOORD Lieve pap en mam, dank voor het gevoel altijd voor me klaar te staan. Voltooiing van het boekje is de bevestiging van de les die jullie me meegegeven hebben, dat je met doorzettingsvermogen alles kan bereiken. Lieve Ilse, achter elke sterke man, staat een sterke(re) vrouw. Dank voor je warmte, liefde en humor. Ik waardeer je steun en ruimte die je me geeft in de spagaat die ik voel tussen gezin, werk, wetenschap, vrienden en fietsen. Lieve Sybe, wat een fijne vent ben je! Lief, grappig en nieuwsgierig laat je papa en mama dagelijks zien wat werkelijk belangrijk is in het leven! 103 Curriculum vitae 105 CURRICULUM VITAE Axel Robin Deenik was born on May 3th 1969 in Beverwijk, the Netherlands. He grew up at Fort Portal, Uganda, Vleuten and Heelsum, the Netherlands. He graduated from the Wagenings Lyceum and he continued his medical education at the University of Amsterdam. Due to his early interest in orthopedic surgery and sports injuries he attained an internship at the Robert Jones and Agnes Hunt Orthopaedic Hospital in Oswestry. He combined his study with race rowing at the A.S.R. Nereus, which resulted in a national chamionship in the coxed four. Further he participated in the study guidance committee. In 1996 he obtained his medical qualification. In orthopaedic residencies in Sittard and Maastricht he started the randomized controlled trial with the subject hallux valgus. In 2000 he started his orthopaedic training with a surgical residency at the Diaconessenhuis Eindhoven (Dr. W.J. Prakke), orthopaedic residencies at Maaslandziekenhuis in Sittard (Dr. A.D. Verburg), Academisch Ziekenhuis Maastricht (Prof. dr. R.D. Geesink) and Heerlen (Prof. dr. I.C. Heyligers). The advancement of the randomized controlled trial was presented by the author at the congress of the international federation of foot & ankle societies in Naples and did result in the VOCA award. In 2006 he attained a fellowship traumatology at the Radboudumc (Prof. dr. A. van Kampen). Since 2007 he works as a consultant in Ziekenhuis Bronovo, The Hague, with areas of interest the knee, sports injuries, the forefoot and traumatology. He participated as a tutor in orthopaedic education of two nurse practitioners. Further he is secretary for the Geneeskundig Gezelschap ‘s Gravenhage. His main hobby is mountainbiking and cycling. The author is married with Ilse, they have a wonderful son Sybe and live happilly together in the Hague. 107 MEDICINE CONTINUING MEDICAL EDUCATION The Treatment of Hallux Valgus Nikolaus Wülker, Falk Mittag SUMMARY Background: Hallux valgus is the commonest forefoot deformity, with an estimated prevalence of 23% to 35%. It causes symptoms on the medial edge of the foot, the sole, and the small toes. Non-operative treatment may alleviate symptoms but does not correct the deformity of the big toe. Surgery is indicated if the pain persists. The correct operation must be selected from a wide variety of available techniques. Methods: In this article, we selectively review the pertinent literature, including the recommendations of medical societies in Germany and abroad, in the light of our own clinical experience. Results: There have been many clinical trials of various treatments for hallux valgus, but very few of these were randomized, and the case numbers were generally small. Mild deformities are best treated by distal first metatarsal osteotomies, e.g. the Chevron osteotomy. Severe deformities require a soft-tissue procedure at the first metatarsophalangeal joint and a proximal first metatarsal osteotomy. In case of osteoarthritis, and in elderly patients, a resection arthroplasty is preferred; arthrodesis is performed in physically active patients. After correction of hallux valgus, patients can usually bear their full weight on the treated foot while wearing a flat surgical shoe. Proper surgical treatment results in a good or very good outcome in 85% of patients and a satisfactory result in a further 10%. Conclusion: The clinical outcome of present treatments seems to be good in most cases, but large-scale randomized trials are still needed to verify the efficacy of the wide variety of operations and fixation techniques that are currently being offered. ►Cite this as: Wülker N, Mittag F: The treatment of hallux valgus. Dtsch Arztebl Int 2012; 109(49): 857−68. DOI: 10.3238/arztebl.2012.0857 o deformity of the forefoot occurs more frequently than hallux valgus. A recent review estimates the global prevalence of hallux valgus at up to 23% in 18- to 65-year-olds and 35% in those over 65, although of course it is difficult to draw a line between normal and pathological positioning of the great toe (1). The reasons for hallux valgus in an individual case are hard to define: The deformity can often be attributed to ill-fitting shoes, and sometimes there is a familial disposition. Women are much more commonly affected than men, because they frequently wear narrow, high-heeled shoes and often have more flexible soft tissues (2). Although hallux valgus is particularly frequent from the middle years of life upwards, many patients of both sexes are affected at a young age, usually in one foot but sometimes in both (1–3, e1–e3). The pathogenesis of hallux valgus is complex. It is generally accepted that an imbalance of the extrinsic and intrinsic foot muscles and the ligamentous structures is involved. Even in the normal foot, the extensor and flexor tendons are slightly off-center to lateral. This is compensated by other foot muscles and ligaments, however, so that overall the forces are balanced. This equilibrium is sensitive to internal and external influences (e.g., the wearing of narrow, high-heeled, and pointed shoes). The energy required to maintain the developing deformity becomes ever smaller. The eventual result is valgus deformity of the great toe with spreading of the forefoot (3–6, e3). Hallux valgus causes symptoms in three particular ways. First and foremost is pain in the bunion, the pressure-sensitive prominence on the medial side of the head of the first metatarsal. It hurts to wear a shoe. Furthermore, the valgus deviation of the great toe often results in a lack of space for the other toes. They become displaced, usually upwards, leading to pressure against the shoe. This is termed hammer toe or claw toe. Finally, normal function of the forefoot relies heavily on the great toe pressing down on the ground N Symptoms Hallux valgus causes pain particularly in the bunion on the inner side of the foot, on loading under the foot and in the smaller toes Department of Orthopaedic Surgery, Tübingen University Hospital: Prof. Dr. med. Wülker, Dr. med. Mittag Deutsches Ärzteblatt International | Dtsch Arztebl Int 2012; 109(49): 857–68 857 MEDICINE Figure 1: Hallux valgus with a hallux valgus angle of 20° and pain from pressure on the bunion medially during gait. Since the valgus deformity stops this happening to a sufficient degree, metatarsal heads II–V are overloaded. The resulting pain is referred to as transfer metatarsalgia. position of the great toe is not the only deformity. In the majority of cases the metatarsus is splayed, increasing the prominence of the metatarsophalangeal joint. Moreover, the great toe is often somewhat pronated, so that the nail faces medially. The examiner should also establish whether the deformity is flexible, i.e., whether it can be corrected by manipulation, and whether motion of the metatarsophalangeal joint is limited by pain, which would point to osteoarthritis. Furthermore, the stability of the first tarsometatarsal joint should be determined. The tarsus and hindfoot must also be investigated to exclude accompanying deformities. Investigation of peripheral vascular perfusion and motor and sensory functions is obligatory. A dorsoplantar radiograph with the foot under load is required. An additional lateral or oblique view in this position contributes little extra information because the bones are superimposed, but may help to depict deformities of the smaller toes and instability of neighboring joints. Only under conditions of loading can the angle between the first and second metatarsals (intermetatarsal angle) be determined accurately. The radiograph will show the congruence of the metatarsophalangeal joint, i.e., whether a subluxation exists, and should also be inspected for any signs of osteoarthritis (joint space narrowing, subchondral sclerosis). Conservative treatment Learning goals The learning goals for readers of this article are: ● The ability to distinguish accurately between the different variants of hallux valgus deformity ● Attainment of familiarity with the possibilities and limitations of conservative, symptomatic treatment of hallux valgus ● The ability to decide when surgery is indicated ● Acquaintance with the various surgical procedures and the indications for each particular method. Diagnosis The lateral deviation of the great toe is obvious when the patient stands barefoot (Figure 1). In addition, one can measure the angle between the longitudinal axes of the first metatarsal and the proximal phalanx of the great toe, with the vertex at the head of the first metatarsal (hallux valgus angle). An angle greater than 15° no longer corresponds to the norm, although there is considerable interindividual variation (3). The valgus Radiograph A radiograph with the patient in standing position shows the angle between metatarsal I and metatarsal II, as well as the congruence of the first metatarsophalangeal joint and any signs of osteoarthritis. 858 Only while the skeleton is still growing can the position of the great toe be improved with lasting effect. A night splint can be prescribed to move the great toe to medial. After the end of growth, adequate correction is no longer possible and conservative treatment is restricted to alleviation of symptoms. By the time patients consult a physician, most of them have already resorted to softer and wider shoes to alleviate pain from pressure on their bunion. Ring pads and other dressings tend to increase the prominence of the bunion and are usually unsuccessful. Antiphlogistic salves can be administered locally, nonsteroidal antiinflammatory drugs systemically. Pain in the smaller toes can be alleviated with pads and toe straighteners. Wide, soft shoes are helpful if they give the toes enough space. Once hammer toes or claw toes have developed, however, surgery is necessary. In our experience, insoles are effective for alleviation of metatarsalgia (7). They must feature a pad that pushes the metatarsals upward proximal to the Conservative treatment Pain on standing and walking can be alleviated by inlays under the forefoot. Permanent improvement of the position of the great toe is not possible. Deutsches Ärzteblatt International | Dtsch Arztebl Int 2012; 109(49): 857–68 MEDICINE TABLE 1 A selection of well-known surgical procedures for treatment of hallux valgus No. Name Principle Site References Advantages/disadvantages Comments 1 Akin Corrective osteotomy Proximal phalanx Akin (1925) (8), Arnold (2008) (e4), Chacon et al. (2012) (9) In combination with other techniques, stability technically difficult Used in hallux valgus interphalangeus 2 Metatarsophalangeal joint arthrodesis Fusion Metatarsophalangeal joint Kumar et al. (2010) (10) Permanent correction, loss of mobility, subsequent osteoarthritis Used in severe deformities and/or hallux rigidus 3 Basal osteotomy Corrective osteotomy Metatarsal I, proximal Mann (1992) (11), Wülker (2005) (12) In combination with soft tissue intervention, stability technically difficult, implant necessary, not possible if tarsometatarsal joint is unstable Suitable for correction of severe deformities 4 Chevron Corrective osteotomy Metatarsal I, distal Austin (1981) (13), Wülker (2005) (12) Reliable technique, little soft tissue trauma, implant necessary, not possible with severe deformity, reduced perfusion of head of metatarsal I Used in mild deformities 5 Hohmann Corrective osteotomy Metatarsal I, distal Hohmann (1923) (14) Little stability with wires or sutures, reduced perfusion of head of metatarsal I Now hardly ever used 6 Hueter Resection arthroplasty Metatarsal I, head Hueter (1871) (15), Mayo (1908) (e6) Simple technique, lack of support for head of metatarsal I, transfer metatarsalgia frequent No longer used 7 Keller-Brandes Resection arthroplasty Proximal phalanx, proximally Keller (1904) (16), Brandes (1929) (17) Simple technique, loss of hallux function, transfer metatarsalgia frequent Used in elderly and inactive patients 8 Kramer Corrective osteotomy Metatarsal I, distal Kramer (1990) (18) Little stability with wires, reduced perfusion of head of metatarsal I Now hardly ever used 9 Lapidus Fusion Tarsometatarsal joint Lapidus (1934) (19), Taylor et al. (2008) (20), Hyer et al. (2011) (e7) In combination with soft tissue intervention, implant necessary, loss of mobility, technically difficult, danger of pseudarthroses Used in cases of TMT-I joint instability or osteoarthritis 10 McBride Soft tissue balanc- Metatarsophaing with reposition- langeal joint ing of the adductor tendon McBride (1928) (21) Frequent recurrence owing to inadequate correction of metatarsal I Now hardly ever used, replaced by soft tissue procedure 11 Scarf Corrective osteotomy Metatarsal I, diaphyseal Patton et al. (1994) (e8), Weil (2000) (22), Adam et al. (2011) (e9) Accurate correction angle, implant necessary, extensive soft tissue dissection Suitable for correction of mild to moderate deformities 12 Soft tissue procedure Soft tissue balancing Metatarsophalangeal joint Mann (1992) (4) Complete soft tissue correction, two skin incisions necessary Usually in combination with proximal osteotomy Surgical procedures The different surgical procedures are based on various underlying principles, e.g., correction osteotomy, resection arthroplasty, or arthrodesis. Deutsches Ärzteblatt International | Dtsch Arztebl Int 2012; 109(49): 857–68 Disadvantage of some operative techniques A disadvantage of some operative techniques is reduced perfusion of the head of metatarsal I. 859 MEDICINE Figure 2: Sites of surgical procedures for treatment of hallux valgus. The numbers correspond to those in Table 1 (first column) . Over 150 different operations have been described for the treatment of hallux valgus. A selection of betterknown procedures is presented in Table 1 and Figure 2. There are only a small number of prospective randomized trials comparing different surgical procedures or investigating conservative treatment (Table 2). The whole published literature contains only four publications (23, 29–31) in which operative techniques were compared, none of which reached any clear conclusions. This shows the limits of current scientific knowledge, particularly when it comes to detailed questions of surgery. Whether, for example, the adductor tendon must be divided or the intermetatarsal angle corrected has to be decided according to the patient’s specific deformity. These techniques can hardly be randomized without taking account of the exact deformity. The wide variety of deformities would necessitate very large numbers of cases, involving the cooperation of many different centers. For this reason, prospective randomized trials concern themselves with details of surgical technique or compare very similar operations. The actual choice of procedure over the whole spectrum of hallux valgus deformities thus depends essentially on the surgeon's expertise and experience. A Cochrane review by a group of podiatrists in London, originally published in 2004 and updated in 2009, analyzed a total of 21 randomized or “quasirandomized” clinical trials that were essentially equivalent to the studies listed in Table 2 with regard to operative technique. The conclusion: “The methodological quality of the […] trials was generally poor and trial sizes were small.” No difference was found between conservative treatment and no treatment. No recommendations were given with regard to operative techniques. Trials of operative techniques have yielded Metatarsalgia In our experience, metatarsalgia can be effectively alleviated with insoles. These must have a pad that exerts upward pressure on the metatarsals proximal to the pressure-sensitive metatarsal heads. Study findings The literature contains only few prospective randomized trials comparing different surgical procedures or investigating conservative treatment. Four studies that did compare procedures all came to no clear conclusion. pressure-sensitive heads. It often suffices to advise the patient to wear shoes with soft soles and without excessively high heels (no more than 4 cm). The malposition of the great toe, of course, cannot be corrected with insoles alone. Study findings 860 Deutsches Ärzteblatt International | Dtsch Arztebl Int 2012; 109(49): 857–68 MEDICINE TABLE 2 Randomized clinical trials of hallux valgus surgery Study [reference] Comparison Klosok et al. (1993) [23] Chevron osteotomy versus Wilson osteotomy Resch et al. (1994) [24] Number of patients Results Comments 87 Quicker return to work with Chevron osteotomy, better functional outcome with Wilson osteotomy Three years' follow-up, Wilson osteotomy now hardly ever used Chevron osteotomy with versus without adductor tenotomy 84 Hallux correction 9.8°/7.5° with/without tenotomy, no other differences Limited relevance, because capsule not divided Connor et al. (1995) [25] Rehabilitation with versus without continuous motion after Chevron osteotomy 39 Mobility better with continuous motion Only 90 days' follow-up, limited relevance for treatment Easley et al. (1996) [26] Curved versus proximal Chevron osteotomy 97 No significant differences regarding correction, but swifter and more reliable healing with proximal Chevron osteotomy Only 2 years' follow-up, various fixation techniques, limited relevance for treatment Calder et al. (1999) [27] Suture versus screw fixation in Mitchell osteotomy 30 Better results with screws Superior stability with screws was to be expected, Mitchell osteotomy now seldom used Torkki et al. (2003) [28] Surgery versus 1-year conservative treatment with or without orthesis 209 Surgery superior to conservative treatment after 1 year, no difference after 2 years Unclear interpretation of data Faber et al. (2004) [29] Hohmann osteotomy versus Lapidus operation 101 No significant difference, also not with regard to hypermobility of first tarsometatarsal joint No severe deformities included, only 2 years' follow-up Saro et al. (2007) [30] Lindgren versus Chevron osteotomy 100 No significant differences, both procedures suitable only for mild deformities Long follow-up (6 years); comparison of two very similar techniques; Lindgren techniques now seldom used Deenik et al. (2008) [31] Scarf osteotomy versus Chevron osteotomy 136 No significant differences, good results in both groups Comparison of two very similar techniques; the authors recommend Chevron osteotomy because it is technically simpler Tonbul et al. (2009) [32] Screw versus K-wires for stabilization; curved, distal metatarsal osteotomy 16 No significant differences, good results in both groups Groups too small, limited relevance for treatment du Plessis et al. (2011) [33] Exercises versus night splint in conservative hallux valgus treatment 30 No difference between the groups Groups too small Pentikäinen et al. (2012) [34] Chevron osteotomy with fixation (resorbable peg) versus no fixation, with plaster versus elastic bandage postoperatively 100 Osteotomy displacement 3.9 mm with fixation versus 3.1 mm without fixation (statistically significant), no difference for postoperative treatment Accuracy of measurement technique not described, difference clinically irrelevant Operative techniques Whether, for example, the adductor tendon should be divided or the intermetatarsal angle corrected has to be decided according to the individual deformity. Deutsches Ärzteblatt International | Dtsch Arztebl Int 2012; 109(49): 857–68 Trials All randomized controlled trials had case numbers that were too small and follow-up periods that were too short. 861 MEDICINE FIGURE 3 Hallux valgus Osteoarthritis of the metatarsophalangeal joint No osteoarthritis of the metatarsophalangeal joint Inactive patient Physically active patient Resection arthroplasty Arthrodesis Hallux valgus interphalangeus Incongruent metatarsophalangeal joint Congruent metatarsophalangeal joint Osteotomy of proximal phalanx Distal soft tissue intervention Chevron osteotomy Intermetatarsal angle < 10º < 10º 10º –15º >15º Distal articular angle <10º >10º without possibly with basal osteotomy MT-I without with medial wedge excision The algorithm used at our institution to classify hallux valgus and select the most appropriate surgical procedure. This algorithm broadly corresponds to other published recommendations (36). Distal and proximal repositioning of metatarsal I and arthrodesis can be accomplished by means of various osteotomies and fixation techniques. MT-I, metatarsal I inconsistent results; no one technique was superior to all others. Notably, in some studies 25% to 33% of patients were unsatisfied with the outcome of the operation although the relevant angles were improved. The authors of the Cochrane review criticized the maximal 3 years’ postoperative follow-up, writing that 20 to 30 years would be desirable (35). The German Orthopaedic Foot and Ankle Society (DAF), a section of the German Society for Orthopaedics and Orthopaedic Surgery (DGOOC), has issued an S1 guideline on hallux valgus (36). On the basis of studies yielding evidence of levels III and IV, an algorithm was set up that distinguishes between Algorithm Metatarsophalangeal joint with or without osteoarthritis, congruent or incongruent metatarsophalangeal joint, patient with high or low degree of physical activity. 862 mild, moderate, and severe deformities and lists distal, diaphyseal, and proximal osteotomies and arthrodesis of the first tarsometatarsal joint as surgical options. Each procedure can be used for all deformities, with two exceptions: proximal osteotomy and arthrodesis should not be employed for mild deformities, and distal osteotomy is not appropriate for severe hallux valgus. The guideline includes the following recommendations without giving any references: division of the soft tissues lateral to the metatarsophalangeal joint in severe deformities; corrective retrocapital osteotomy in the presence of a tilted joint surface; resection arthroplasty in the case of poor mobility; shortening of metatarsal I in osteoarthritis of the metatarsophalangeal joint. Therefore, although the guideline is formulated in quite general terms, its recommendations essentially correspond to those given here. An example of the other reviews on the treatment of hallux valgus is that published by Wanivenhaus et al. (37). In the face of the high number of different operations described and the mostly low level of evidence of the investigations published, it is extremely difficult to give treatment recommendations based on high-level evidence. The surgical procedures described in this review reflect the practice in our own institution. Other procedures that are not discussed here may be equally suitable, but any surgery must be specifically designed to eliminate the deformity concerned. Indications for surgery Cosmetic surgery is out of place in hallux valgus. The danger is far too great that a previously symptom-free patient will suffer pain for weeks or even months after the intervention. For surgical treatment to be indicated, the patient must have pain that is not alleviated by a simple change of shoes or by other, conservative treatments. Moreover, the pain must be regular in occurrence and must noticeably impair the function of the affected foot. The pain does not necessarily have to involve the great toe itself. Patients often initially complain of pain arising from the other digits, which may already have been forced upwards as hammer or claw toes. In such a case it is not enough to correct the deformity of the smaller toes; the hallux valgus must be rectified. The principal contraindication to surgery is arterial occlusive disease (e10). Because it is the part of the body most distant from the heart, the foot is the first place where decreased perfusion will make itself Level of evidence In the face of the high number of different operations described and the mostly low level of evidence of the investigations published, it is impossible to give treatment recommendations based on high-level evidence. Deutsches Ärzteblatt International | Dtsch Arztebl Int 2012; 109(49): 857–68 MEDICINE noticed. If the pedal pulse is not distinct, the vascular status must be determined. Only if sufficient perfusion is assured can surgery take place. Diabetes, even with early polyneuropathy, does not represent a contraindication. Hallux valgus can also be treated surgically in the presence of chronic polyarthritis or other rheumatic diseases, although care must be taken to select an appropriate procedure. Operative technique The soft tissue covering of the foot is extremely thin, and this hampers wound healing. Furthermore, perfusion is poorest in the foot because of its distance from the heart. Finally, of all parts of the body the foot is subjected to the greatest mechanical stresses. For these reasons wound healing problems, depending on the extent of the operation and the patient’s medical history, occur more frequently in the foot than in most other regions. The aim is uncomplicated wound healing in at least 99% of patients, in our experience an attainable goal. Particular care must therefore be taken when operating on the great toe. The duration of ischemia must be as short as possible. This is best achieved by wrapping a tourniquet around the foot after sterile draping. The incision should grant direct access to the operation site without undue dissection of soft tissues. There should be no hemostasis by means of electrocautery. Excessive retraction should be avoided. Care must be taken to ensure proper compression by the bandage applied postoperatively. Only dry bandages may be used in order to avoid maceration of the wound margins. The suture for wound closure should be left in place until 14 days after surgery. Although functional rehabilitation under full loading is generally possible, the foot must be elevated to avoid excessive swelling. Surgical procedures To be able to cope with all variants of hallux valgus, the surgeon needs a command of around four procedures. The basic distinction is between operations that restore the normal anatomy of the forefoot, and thus come into question particularly in younger patients, and interventions where the joint is sacrificed (resected or fused), which are considered especially in older patients and in the case of osteoarthritis of the metatarsophalangeal joint (12, 38, 39). Figure 3 provides an overview of the classification of hallux valgus and the commonest surgical procedures. These will be described in detail in the following. Surgical procedure according to deformity The success of an operation depends crucially on the selection of the best procedure for the individual deformity. Deutsches Ärzteblatt International | Dtsch Arztebl Int 2012; 109(49): 857–68 a b Figure 4: Radiographs of a foot with mild hallux valgus a) Mild malposition with an intermetatarsal angle of 13°, a congruent metatarsophalangeal joint, and a flexible deformity b) After correction by Chevron osteotomy: the head of metatarsal I was shifted 5 mm to lateral and the capsule on the medial side of the first metatarsophalangeal joint was tightened Mild deformities Mild deformities are found predominantly in young women (Figure 4a). The patients complain principally of pressure pain in the bunion, which is moderately prominent. The deformity is flexible, i.e., the hallux can be restored to the normal position manually, without any significant resistance. Moreover, the metatarsus is only slightly splayed, so that the intermetatarsal angle is less than 15° on a weight bearing radiograph. The mobility of the first metatarsophalangeal joint is not restricted, and no osteoarthritis is seen on the radiograph. Mild deformities can be effectively treated by distal metatarsal I osteotomies, e.g., chevron osteotomy (Figure 4b). This intervention, initially known as Austin osteotomy, was first described in 1962 (13). A V-shaped cut is made in the head of metatarsal I and the bone is displaced laterally by one third to a half of its width, thus correcting the intermetatarsal angle. In addition, the exostosis on the medial aspect of the head of metatarsal I is shaved off and the capsule tightened so that by the end of the operation the great toe is in the proper position. Fixation with a small implant is Contraindication The principal contraindication to surgery is arterial occlusive disease. 863 MEDICINE a b Figure 5: Radiographs of a foot with severe hallux valgus a) Severe deformity with an intermetatarsal angle of 19°, an incongruent metatarsophalangeal joint, and a rigid deformity b) After correction by a distal soft tissue intervention with release of the soft tissues on the lateral side and tightening of the soft tissues on the medial side of the metatarsophalangeal joint, with additional correction of the position of metatarsal I by an osteotomy at its base necessary to prevent reposition loss, but an inexpensive small-fragment screw or a wire will suffice. There is no consensus on the advisability of carrying out additional lateral release in the case of an incongruent metatarsophalangeal joint. We do not do so in the context of chevron osteotomy, for two reasons: (1) lateral release is unnecessary in mild deformities, and other procedures are available for more severe cases of hallux valgus; (2) lateral release increases the risk of poor perfusion of the head of metatarsal I with consequent necrosis. Postoperatively the toe must be held straight for 6 weeks with a corrective bandage. During this time the patient has to wear a flat-soled healing shoe that allows full weight bearing. Severe deformities Severe deformities mostly affect the middle-aged and elderly, predominantly women (Figure 5a) (1). The great toe can no longer be fully repositioned manually, and on radiographs the joint is seen to be incongruent, i.e. the proximal phalanx is subluxated laterally on the head of metatarsal I. The metatarsus is distinctly Mild deformities Best suited for mild deformities are distal osteotomies of metatarsal I, particularly chevron osteotomy. 864 splayed, further increasing the prominence of the bunion on the medial aspect of the head of metatarsal I. The intermetatarsal angle is 15° or more on weight bearing radiographs (3). In this case the soft tissues lateral to the first metatarsophalangeal joint must be divided—this is termed lateral release. Various versions of this soft tissue intervention have been known for many years and were particularly recommended by McBride (21). The technique most widely used today was first described by Mann (11). An intermetatarsal angle of 15° or more necessitates an additional corrective osteotomy at the base of metatarsal I, where the potential for correction is greater (Figure 5b). Many different osteotomy techniques have been described. The simplest are opening osteotomies that are then filled medially with bone, for example from the resected exostosis. At the same time, osteotomies in two planes provide greater stability, because the bony contact surface is increased and the danger of dislocation reduced. After correction the osteotomy has to be stabilized with an implant. Here too, an inexpensive cancellous screw suffices. We take the view that complicated, costly implants such as fixed angle plates are unnecessary. When closing the capsule on the medial side of the metatarsophalangeal joint, the surgeon must take great care to ensure that the capsule is sufficiently tightened after resection of the bony pseudoexostosis. Hallux valgus et rigidus Osteoarthritis of the metatarsophalangeal joint is usually found in older patients. On closer inspection, most patients aged 65 years or more with hallux valgus show articular degeneration (Figure 6a). There is no longer any point in carrying out reconstructive procedures, because joint mobility is usually not adequately restored and long-term pain often results. The preferred procedure in physically inactive patients is therefore a very old intervention, namely resection arthroplasty with removal of the base of the proximal phalanx of the great toe (16, 17). The procedure is simple and the rehabilitation time short. In our experience the patients are moving around normally without special shoes within 4–6 weeks. One disadvantage is almost total loss of function of the great toe, which no longer has sufficient contact with the ground during the heel rise phase of gait. This frequently results in pain under the heads of the middle metatarsals, referred to as transfer metatarsalgia. Even pronounced deformities can be corrected, but generally Severe deformities Severe deformities necessitate soft tissue intervention around the first metatarsophalangeal joint, as a rule accompanied by an osteotomy at the base of metatarsal I. Deutsches Ärzteblatt International | Dtsch Arztebl Int 2012; 109(49): 857–68 MEDICINE an accompanying osteotomy at the base of metatarsal I is required (Figure 7). An alternative in patients with hallux valgus et rigidus who still have a high level of physical activity is arthrodesis of the joint. Contrary to the common expectation, arthrodesis is an operation that preserves function, because the great toe comes into firm contact with the ground during heel rise, relieving the metatarsal heads of the other rays. This means that a certain level of sporting activity is possible. A further advantage is the definitive positioning of the great toe. Thus arthrodesis can be considered especially for very pronounced deformities. In the presence of a greatly increased intermetatarsal angle, care must be taken to compress the metatarsus to enable proper adjustment of the angle between the proximal phalanx and metatarsal I. Fixation is achieved preferably with a dorsal plate (Figure 6b). This departs from strict biomechanical principles, but is practicable and successful. A tension screw may be added. Special cases Occasionally there are special indications. If the distal phalanx of the great toe is angled to lateral (hallux valgus interphalangeus), osteotomy of the proximal phalanx with removal of a medial-based wedge is required (generally in addition to one of the procedures described above) (8). Absolutely accurate restoration of the angle is not possible, but if the wedge has a base of 1 to 3 mm the correction is usually adequate. Complicated and costly implants (staples, screws) are available, but adequate fixation can be achieved with a simple, inexpensive suture threaded through drill holes. Occasionally the joint surface at the head of metatarsal I is tilted to lateral, particularly in cases where the hallux valgus arose before the patient reached adulthood. The orientation of the joint surface must then be corrected by osteotomy involving removal of a medialbased wedge from the distal portion of metatarsal I. Rehabilitation In our institution all operations on the forefoot are followed by full weight bearing in a postoperative shoe with a flat, stiff sole that is worn for 6 weeks. Because of the frequent tendency towards swelling, patients are advised to keep the affected foot raised for much of the time during the first 2 weeks. After reconstructive interventions a corrective dressing must be worn for up to 6 weeks. The patient changes the dressing each day. Osteoarthritis In the presence of osteoarthritis of the first metatarsophalangeal joint and in very elderly patients, resection arthroplasty or arthrodesis of the first metatarsophalangeal joint produce the best results. Deutsches Ärzteblatt International | Dtsch Arztebl Int 2012; 109(49): 857–68 a b Figure 6: Radiographs of a foot with hallux valgus in a 68-year-old man a) Osteoarthritis of the first metatarsophalangeal joint with narrowing of the joint space b) After arthrodesis. The patient wears a postoperative shoe with a stiff sole for 6 weeks and unlimited weight bearing is allowed immediately after surgery Patients can usually walk normally after 8 to 12 weeks. Implants can be removed from 6 to 9 months after surgery, but can be left in situ in elderly patients if they are causing no symptoms. Conclusion The literature contains practically no well-controlled prospective trials; in particular, no comparison of different treatment procedures. Analysis of the large number of retrospective studies with follow-up for up to 5 years shows that overall, 85% of patients are satisfied and have a good clinical result. Ten percent are less satisfied and show a less beneficial outcome, and in 5% the results of surgery are poor. This corresponds with our own experience. Foremost among the complications of reconstructive procedures are recurrences, sometimes as a result of inadequate surgical correction, sometimes because of poor wound healing (40). The quality of wound healing cannot be precisely predicted, and the rate of wound healing problems is generally stated as 2% to 4%; our experience, however, indicates that this figure should be lower. Pseudarthrosis and necrosis of the head of metatarsal I are rare (e11, e12). Hallux valgus et rigidus There is no longer any point in carrying out reconstructive procedures, because joint mobility is usually not adequately restored and long-term pain often results. 865 MEDICINE 8. Akin OF: The treatment of hallux valgus: a new operative procedure and its results. Med Sentinel 1925; 33: 678–9. 9. Chacon Y, Fallat LM, Dau N, Bir C: Biomechanical Comparison of Internal Fixation Techniques for the Akin Osteotomy of the Proximal Phalanx. J Foot Ankle Surg 2012; 51: 561–5. 10. Kumar S, Pradhan R, Rosenfeld PF: First metatarsophalangeal arthrodesis using a dorsal plate and a compression screw. Foot Ankle Int 2010; 31: 797–801. 11. Mann RA, Rudicel S, Graves SC: Repair of hallux valgus with a distal soft-tissue procedure and proximal metatarsal osteotomy. A longterm follow-up. J Bone Joint Surg Am 1992; 74: 124–9. 12. Wülker N, Suckel A: Osteotomien des Mittelfußes beim Hallux valgus. Orthopäde 2005; 34: 726–34. 13. Austin DW, Leventeen EO: A new osteotomy for hallux valgus. Clin Orthop 1981; 157: 25–30. 14. Hohmann G: Über Hallux valgus und Spreizfuß, ihre Entstehung und physiologische Behandlung. Arch Orthop Unfall Chir 1923; 21: 525–50. 15. Hueter K: Klinik der Gelenkkrankheiten. Leipzig 1871. a b Figure 7: Radiographs of the right foot of a 75-year-old woman a) Hallux valgus with slight narrowing of the joint space. The intermetatarsal angle is 17° b) Because joint surface degeneration is regularly found at operation in patients of this age, the deformity was corrected by resection arthroplasty with a proximal osteotomy to correct the intermetatarsal angle 16. Keller WL: The surgical treatment of bunions and hallux valgus. NY Med J 1904; 80: 741–2. 17. Brandes M: Zur operativen Therapie des Hallux valgus. Zbl Chir 1929; 56: 2434–40. 18. Kramer J: Die Kramer-Osteotomie zur Behandlung des Hallux valgus und des Digitus quintus varus. Operat Orthop Traumatol 1990; 2: 14–38. 19. Lapidus PW: Operative correction of metatarsus varus primus in hallux valgus. Surg Gynecol Obstet 1934; 58: 183–91. Conflict of interest statement The authors declare that no conflict of interest exists. Manuscript received on 30 March 2012, revised version accepted on 9 October 2012. Translated from the original German by David Roseveare. REFERENCES 1. Nix S, Smith M, Vicenzino B: Prevalence of hallux valgus in the general population: a systematic review and metaanalysis. J Foot Ankle Res 2010; 3: 21. 2. Nguyen US, Hillstrom HJ, Li W, et al.: Factors associated with hallux valgus in a population-based study of older women and men: the MOBILIZE Boston Study. Osteoarthritis Cartilage 2010; 18: 41–6. 3. Wülker N: Hallux valgus – Hallux rigidus. Stuttgart: Enke 1997; 3–32. 4. Mann RA, Coughlin MJ: Hallux valgus: etiology, anatomy, treatment and surgical considerations. Clin Orthop 1981; 157: 31–41. 5. Perera AM, Mason L, Stephens MM: The pathogenesis of hallux valgus. J Bone Joint Surg Am 2011; 93: 1650–61. 6. Wülker N: Hallux valgus. Orthopäde 1997; 26: 654–64. 7. Stinus H, Weber F: Einlagen bei Vorfußdeformitäten. Orthopäde 2005; 34: 776–81. 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Wülker N, Stephens MM, Cracchiolo A III: Operationsatlas Fuß und Sprunggelenk. Stuttgart: Thieme 2007; 3–64. 40. Wülker N: Fehlschläge in der Hallux-valgus-Chirurgie. Orthopäde 2011; 40: 384–91. Corresponding author Prof. Dr. med. Nikolaus Wülker Orthopädische Universitätsklinik Hoppe-Seyler-Str. 3 72076 Tübingen, Germany [email protected] @ For eReferences please refer to: www.aerzteblatt-international.de/ref4912 Further Information on CME This article has been certified by the North Rhine Academy for Postgraduate and Continuing Medical Education. Deutsches Ärzteblatt provides certified continuing medical education (CME) in accordance with the requirements of the Medical Associations of the German federal states (Länder). CME points of the Medical Associations can be acquired only through the Internet, not by mail or fax, by the use of the German version of the CME questionnaire within 6 weeks of publication of the article. 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Solutions: 1e, 2c, 3c, 4d, 5e, 6a, 7c, 8c, 9e, 10d Deutsches Ärzteblatt International | Dtsch Arztebl Int 2012; 109(49): 857–68 867 MEDICINE Please answer the following questions to participate in our certified Continuing Medical Education program. Only one answer is possible per question. Please select the answer that is most appropriate. Question 1 Question 6 The hallux valgus deformity consists principally of lateral deviation of the great toe. However, there are further deviations from normal forefoot anatomy. Which of the following is one of these? a) A prominence on the medial aspect of the head of metatarsal V b) Shortening of the Achilles tendon c) Pronation of the whole foot d) Widening of the metatarsus (splay foot) e) Excessive shortness of metatarsal IV What is one of the characteristics of mild hallux valgus deformity? a) Limited mobility of the first metatarsophalangeal joint b) Simultaneous claw toe c) A flexible deformity d) An intermetatarsal angle of more than 15° e) Osteoarthritis of the first metatarsophalangeal joint on radiography Question 2 Question 7 When surgical correction of hallux valgus is indicated, a further diagnostic examination is required. What is it? a) Weight bearing radiograph in dorsoplantar projection b) Magnetic resonance imaging of the forefoot c) Bone scintigraphy d) Lateral radiography of the forefoot without load e) Sonography of the metatarsophalangeal joint What is one of the findings in severe hallux valgus deformity? a) An incongruence (subluxation) of the first metatarsophalangeal joint on radiography b) An intermetatarsal angle of less than 10° c) Osteoporosis d) Absent pedal pulse e) Simultaneous flat foot Question 3 How can lasting correction of hallux valgus deformity in an adult be achieved by conservative means? a) Insoles with a pad b) Soft shoes c) Night splints d) Cannot be achieved e) Splay foot bandage Question 8 Which operation for hallux valgus is particularly suitable for older, inactive patients who also have painful osteoarthritis of the first metatarsophalangeal joint? a) Chevron osteotomy b) Distal soft tissue intervention with basal osteotomy c) Distal osteotomy of metatarsal I d) Corrective osteotomy of the proximal phalanx e) Resection arthroplasty Question 4 When is surgical correction of hallux valgus indicated? a) When high-heeled shoes can no longer be worn b) When the symptoms regularly cause noticeable limitation of daily activities c) When the radiograph shows a hallux valgus angle of more than 20° d) When night splints do not improve the position of the great toe e) When degenerative changes in the first metatarsophalangeal joint can be seen on magnetic resonance imaging Question 9 What should always be observed in operations for hallux valgus? a) Extensive hemostasis by means of electrocautery b) Loose wound bandage without compression c) As little dissection of soft tissues as possible d) Ischemia for as long as possible e) Suture removal after about a week Question 5 Which of the following is most likely to contraindicate surgical correction of hallux valgus? a) A peripheral perfusion disorder b) Chronic polyarthritis c) Diabetes mellitus d) Bilateral hallux valgus e) Osteoarthritis of the first metatarsophalangeal joint Question 10 868 Deutsches Ärzteblatt International | Dtsch Arztebl Int 2012; 109(49): 857–68 What is an advantage of Chevron osteotomy? a) Complete soft tissue correction b) Can be used in severe deformities c) No implant necessary d) Little soft tissue trauma e) Good perfusion of the head of metatarsal I MEDICINE CONTINUING MEDICAL EDUCATION The Treatment of Hallux Valgus Nikolaus Wülker, Falk Mittag eReferences e1. 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Adam SP, Choung SC, Gu Y, O’Malley MJ: Outcomes after scarf osteotomy for treatment of adult hallux valgus deformity. Clin Orthop Relat Res 2011; 469: 854–9. e10. Williams DT, Price P, Harding KG: The influence of diabetes and lower limb arterial disease on cutaneous footperfusion. J Vasc Surg 2006; 44: 770–5. e11. Lehman DE: Salvage of complications of hallux valgus surgery. Foot Ankle Clin 2003; 8: 15–35. e12. Sammarco GJ, Idusuyi OB: Complications after surgery of the hallux. Clin Orthop Relat Res 2001; 391: 59–71. Deutsches Ärzteblatt International | Dtsch Arztebl Int 2012; 109(49) | Wülker, Mittag: eReferences I