American Journalof Orthopedics

Transcription

The
A Supplement to
American
Journal of
Orthopedics
®
Volume XXXVII
Number 8S•August 2008
www.amjorthopedics.com
A Peer-Reviewed Journal Referenced in Index Medicus/Medline
Innovations in the Treatment of Hand
and Elbow Arthritis
Value-Added Innovation Should
Be Responsible and Relevant
Matthew Tomaino, MD, MBA, Guest Editor
Total Joint Arthroplasty for
the Arthritic Thumb
Carpometacarpal Joint
Alejandro Badia, MD, FACS
Trapezium-Sparing Options
for Thumb Carpometacarpal
Joint Arthritis
Julie E. Adams, MD, Scott P. Steinmann, MD,
and Randall W. Culp, MD
Total Wrist Arthroplasty
Amit Gupta, MD
Indications for Ulnar Head
Replacement
Richard A. Berger, MD, PhD
Radial Head Fractures and the
Role of Radial Head Replacement
William Patrick Cooney, MD
The Emerging Role for
UNI-ElbowTM Arthroplasty
Matthew Tomaino, MD, MBA
Educational support provided by Small Bone Innovations.
The
A Supplement to
American
Journal of
Orthopedics
Volume XXXVII
No. 8S
August 2008
®
I nnovations
in the
T reatment
3
of
H and
and
E lbow A rthritis
Value-Added Innovation Should Be
Responsible and Relevant
4
Total Joint Arthroplasty for the Arthritic Thumb Carpometacarpal Joint
8
Trapezium-Sparing Options for Thumb Carpometacarpal Joint Arthritis
Julie E. Adams, MD, Scott P. Steinmann, MD,
and Randall W. Culp, MD
12
17
Indications for Ulnar Head Replacement
21
Radial Head Fractures and the Role of Radial
Head Replacement: Current Update
Amit Gupta, MD, FRCS
William P. Cooney, MD
26
The Emerging Role for Uni-ElbowTM Arthroplasty
Publisher: The American Journal of Orthopedics (P-ISSN 1078-4519; E-ISSN 1934-3418) (GST 128741063) (IPM # 0607878) is published monthly by Quadrant
HealthCom Inc., with business offices at 7 Century Drive, Suite 302, Parsippany, NJ 07054-4609, telephone (973) 206-3434; fax (973) 206-9378.
Copyright: Quadrant HealthCom Inc. 2008. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any
form or by any means, mechanical, computer, photocopying, electronic recording or otherwise, without the prior written permission of Quadrant HealthCom Inc.
The copyright law of the United States (Title 17, U.S.C., as amended) governs the making of photocopies or other reproductions of copyrighted material.
Opinions: Opinions expressed in articles are those of the authors and do not necessarily reflect those of Quadrant HealthCom Inc. or the Editorial Board. Quadrant HealthCom
Inc. assumes no liability for any material published herein.
2 A Supplement to The American Journal of Orthopedics®
Guest Editorial
Value-Added
Innovation Should
Be Responsible
and Relevant
Matthew M. Tomaino, MD, MBA
O
ur capacity to deal with novelty
is largely a function of the right
side of our brain. The right hemisphere is traditionally described
by some neuroscientists as the
“inferior” one in terms of cognitive functions,
because it is the left side that governs our abilities in language and basic or linear logic. It is
now clear, however, that the right hemisphere is
the “exploratory” part of the brain, dedicated to
discovery and learning.
It has been stated that people who remain
engaged in life often display an attitude of
openness to new and unexpected experiences.
And people who are receptive to novelty and
innovation also tend to be good in a crisis, because
they are open to seeing opportunity in the most
challenging of situations.
As physicians, we understandably take
comfort in relying on time-honored edicts and
“Too often...
we may rely
only on
information
that supports
our point
of view.”
Dr. Tomaino is Founder, Tomaino Orthopaedic Care for Shoulder, Hand, and Elbow,
LLC, Rochester, New York.
Address correspondence to: [email protected]
Am J Orthop. 2008;37(8 suppl): 3. Copyright 2008, Quadrant HealthCom Inc.
existing data. Too often, however,
we may rely on information that
supports only our existing instinct
or point of view, and we may settle
for the best available “mediocre
choice.” Our desires for certainty
may rule out innovative approaches,
perpetuate the status quo, and
slow incremental improvement in
patient satisfaction and functional
outcomes. The challenge is
balancing the responsibility
of providing “evidence-based”
treatment with a desire to provide
a value-added, relevant, “cuttingedge” solution.
Having an open mind—what
Buddhist monks refer to as the “beginner’s mind”—reflects a willingness to
step back from prior knowledge and
existing conventions in order to start over
and cultivate new options. In Zen Mind,
Beginner’s Mind,1 Shunryu Suzuki
acknowledges that “In the beginner’s
mind there are many possibilities, but in
the expert’s there are few.”
In this supplement, I have asked
the authors—each of whom is
uniquely qualified as both expert and
innovator—to highlight responsible
and relevant innovative treatments
for thumb, wrist, and elbow arthritis. I encourage you to study each
article with an open mind, to follow
the evidence base as it develops,
and to conscientiously include novel,
value-added treatment alternatives in
your armamentarium.
References
1. Suzuki S. Zen Mind, Beginner’s Mind.
2006; Boston, Mass: Shambhala Publications,
Inc.
A NOTE FROM THE EDITOR-IN-CHIEF
I would like to thank Small Bone Innovations, Inc., for providing the educational support for this supplement, and the
authors for presenting these new options in the treatment of hand and elbow arthritis. I hope you find this work both
informative and helpful in improving the quality of care for your patients.
Peter D. McCann, MD
Editor-in-Chief
August 2008
3
A Review Paper
Total Joint Arthroplasty for the Arthritic
Thumb Carpometacarpal Joint
Abstract
Thumb basal joint arthritis remains one of the most
common and functionally limiting conditions that orthopedic and hand surgeons encounter in daily practice.
Nevertheless, surgical treatment options have largely
centered on ablative procedures in which the critical
trapezial carpal bone is excised completely. Newer
orthopedic techniques, such as arthroscopy and implant
arthroplasty, have not gained widespread acceptance for
this particular joint. Despite equivocal results for basal
joint implant arthroplasty in early studies, improved
implant design and refinement of surgical indications
support adding this option to the surgeon’s treatment
armamentarium.
F
or painful arthritis of the thumb, the main treatment
goals are to restore thumb function; provide a painfree, stable, and mobile joint; and preserve strength.
Various surgical methods have been proposed to
achieve these goals. Metacarpal osteotomy is best for earlier stages, when joint destruction is limited.1 Arthrodesis
is associated with loss of mobility and transfer of reaction
forces to the neighboring joints.2 Arthroscopy is excellent
for early stages but should be coupled with other procedures,
such as osteotomy, while advanced arthrosis requires some
type of interposition arthroplasty.3 This implies a period of
immobilization to allow spacer adherence, whether artelon
or tendon graft. Procedures like ligament reconstruction/
tendon interposition include trapezium excision, which is
associated with some loss of thumb length and therefore
pinch strength.4 Trapezium excision also requires a period
of immobilization and allows little salvage option if failure
should occur. Silicone implant arthroplasty was proposed
as an alternative but has been shown to be associated with
instability, silicone wear, synovitis, prosthesis fracture, and
prosthesis subluxation.5 Total joint arthroplasty was first
described by de la Caffiniere and Aucouturier.6 This procedure applies the concept of total hip arthroplasty to create a
permanent swivel, within the base of the thumb, that obviates
the need for ligament reconstruction, replaces the joint surface with a mechanical bearing surface for frictionless movement, and provides stability for strong pinch and grasp. The
Dr. Badia is Chief of Hand Surgery, Baptist Hospital of Miami,
Miami, Florida.
Am J Orthop. 2008;37(8 suppl):4-7. Copyright Quadrant
HealthCom Inc. 2008. All rights reserved.
main advantage is rapid functional recovery with trapezium
sparing (options are therefore maintained).
Various implant designs are available for total joint
arthroplasty of the thumb. Historically, the de la Caffiniere
implant was the most widely used and most extensively
studied implant, but it is no longer commercially available. De la Caffiniere reported his own experience with this
implant in 19796 and 1991.7 The GUEPAR implant has been
reported in the French literature.8 Even though surgeons in
different parts of the world continue to use other implants,
the indications and long-term outcomes of those implants
are not reported frequently and are therefore not adequately
established. The Braun prosthesis (Zimmer, Warsaw, IN)
is one such implant. Braun9 first reported its use in a 1982
study of his experience with 22 patients (29 thumbs); in
1985, he reported on his experience with 50 patients.10
There have been few reports on this prosthesis other than
“...it is important to offer this
implant only to older patients
(because of implant longevity)
and to ensure that they do not
have demanding activities...”
these 2 studies, and they were more about implant design
and surgical technique rather than about results and outcome. So, until a retrospective clinical series was reported
in 2006 (Badia & Sambandam11), there had been no clinical
series on this implant since 1985 (Braun10).
This paper reviews the indications, contraindications, and
surgical technique for the Braun-Cutter trapezio-metacarpal
joint prosthesis (SBI, Morrisville, PA) and the outcomes in
treatment of stage III and selected cases of stage IV osteoarthritis of the thumb carpometacarpal joint.
Indications
Optimal patient selection and sound technical execution
are the keys to success with total joint arthroplasty of the
thumb carpometacarpal joint. Typically, this alternative is
indicated for stages III and IV (Figure 1). It is imperative
that, given the stresses at this joint during pinch activity, only
low-demand patients be offered this prosthesis. Cooney12
reported that pinch forces at the pulp are magnified 10to 13-fold when measured at the carpometacarpal level.
A. Badia
Figure 1. Preoperative thumb
radiographs of a patient
with advanced trapeziometacarpal arthritis.
Therefore, it is important to offer this implant only to older
patients (because of implant longevity) and to ensure that
they do not have demanding work or hobby activities that
can increase the risk for loosening and subsequent failure. If
this basic tenet is followed, the procedure may be one of the
most rewarding for the most typical patients presenting with
this painful arthrosis.
The significant advantages of this procedure are rapid
functional recovery and minimal postoperative pain and
inconvenience. Patients seldom require more than several
weeks of hand rehabilitation, which can begin as early as
4 or 5 days after surgery. Early rehabilitation is of particular benefit to the infirm and to the elderly who live alone,
as rapid return to activities of daily living with minimal
outside help is highly valued by these patients, who are
often preoccupied with other, far more significant health
issues. Any surgery that requires a cast or prolonged
recovery will be a great hindrance.
Patients with advanced thumb deformity, including adduction contracture, are also ideal candidates for the procedure.
During excision of the metacarpal base, a complete adductor
release can be performed to restore functional and cosmetic
abduction of the thumb ray. Hyperextension of the metacarpophalangeal joint can be addressed with volar capsulodesis,
or even arthrodesis in severe cases, restoring the normal
kinematics and stable opposition post required of the thumb.
A z-plasty may be necessary for the first web space. That the
implant is constrained helps correct chronic deformities, as
the construct neutralizes joint-deforming forces.
Contraindications
No young or highly active patient should undergo basal joint
metal implant arthroplasty, as it will be doomed to failure. Not
only are joint reactive forces excessive, as previously stated, but
the size of the bones limits the osseous surrounding support on
which each component depends. The trapezial component has
only limited carpal bone encompassing the cement mantle that
maintains the cup in correct orientation. Dorsoradial migration, or even subsidence, can occur if the implant is subjected
to excessive and prolonged stresses. Decisions must be made
about each particular patient as to whether he or she is too
young or too active to undergo this surgery.
Figure 2. Intraoperative view of metacarpal component and
trapezial cup cemented in place prior to reduction.
Other contraindications include bone stock that will not
support the components and a flattened trapezium, which is
best managed by complete resection. In other words, implant
acceptance requires ample trapezium. When there is any
doubt, the device should not be used, and the procedure can be
altered to trapezium resection and ligament reconstruction.
Presence of arthritis in the scaphotrapezial-trapezoidal
(STT) joint is a source of controversy. Advanced radiographic changes or symptomatic findings at this joint
preclude use of the implant, as pain may persist or even
become magnified at this level. However, presence of mild
STT joint degenerative changes on radiography does not
necessarily present a contraindication in our experience.
It is important to directly palpate this joint on the hand
dorsum to rule out painful STT arthritis if the radiograph
suggests any. Again, excisional arthroplasty would be more
appropriate with these findings.
Less common contraindications include prior infection at
this level and neurologic deformity, such as Charcot joint (eg,
syringomyelia) or paralytic contracture affecting the hand.
Surgical Technique
Surgical approach for thumb basal joint arthroplasty consists of a 3- to 4-cm longitudinal lazy S incision performed
over the dorsum at the base of the thumb. This curvilinear
incision is a smaller incision that permits better side-to-side
retraction. It is also less apparent than simple straight lines.
Branches of the superficial sensory radial nerve are identified and protected. Further dissection is carried between the
extensor pollicis longus and extensor pollicis brevis tendons
protecting the dorsal branch of the radial artery. The dorsal
capsule of the trapeziometacarpal joint is opened longitudinally. A transverse incision of about 1.5 cm is made in the
periosteum at the base of the metacarpal, also elevating the
insertion of the abductor pollicis brevis. The periosteum and
the dorsal capsule are reflected proximally as a single flap
so that it can be repaired later. A small sagittal saw is used
to remove the proximal 8- to 10-mm base of the metacarpal. This maneuver facilitates complete release of the joint
August 2008 5
Total Joint Arthroplasty for the Arthritic Thumb CMC Joint
Figure 3. Postoperative
thumb radiographs showing
Braun-Cutter thumb implant
(SBI, Morrisville, PA) in
place and clearly illustrating
cement mantle around components.
capsule and the adductor pollicis from the metacarpal shaft.
This step allows abduction of the thumb metacarpal away
from the palm to improve hand function. At this point, longitudinal traction and flexion are applied to better expose the
trapezial surface. A rongeur is used to remove the marginal
osteophytes. A high-speed burr or the rasp in the tray is used
to create a deep channel within the trapezium or can be used
where the polyethylene cup is to be cemented. For the thumb
metacarpal, 2 broaches of different sizes are available for
preparing the metacarpal canal and allowing the component
to have a generous cement mantle. Both sides of the joint
are prepared for implant placement by irrigating them with
antibiotic solution and drying the cancellous bony surfaces
with gauze. The cup is cemented in the trapezium. Once the
cup has been inserted and the cement cured, a second batch
“ In other words, implant
acceptance requires ample
trapezium.”
of cement is placed in the metacarpal, and the metacarpal
component is inserted. As this stem is collarless, adequate
neck length must be maintained after insertion so that dislocation does not occur. Dislocation can occur when the stem
neck impinges on the edge of the trapezium because of inadequate placement. After proper hardening of this component,
the stem is pressed into place in the cup, and stability and
circumferential motion are assessed with no impingement
on the implant. Any excess cement is excised. With experience, the surgeon can cement both sides of the joint in one
stage, considerably shortening operative time (Figure 2). The
periosteum–capsule flap is closed with absorbable suture,
and meticulous hemostasis is achieved. Intraoperative fluoroscopy is used to check proper alignment and placement
of the prosthesis (Figure 3). I typically close the skin with
4-0 Vicryl Rapide (Ethicon, Inc., Somerville, NJ) and apply
a well-padded short-arm thumb spica splint with the thumb
in opposition (worn for 2 weeks). At this time, rehabilitation is started, and an orthoplast thumb-based spica splint
Figure 4. Photograph taken at follow-up visit 3 weeks after surgery demonstrates functional thumb adduction to small finger
metacarpophalangeal volar crease.
is indicated for further protection during certain activities.
Patients rapidly regain thumb-to-base-of-small-finger opposition with a gentle, active-assisted range-of-motion protocol
(Figure 4).
In the event that a volar capsulodesis is needed, a
Bruner-type incision is made over the palmar aspect of
the metacarpophalangeal joint. The flexor pollicis longus tendon is identified and reflected and the A1 pulley
released. Then a U-shaped incision is made on the volar
plate to create a distally based flap. The metacarpophalangeal joint is then held in 10° of flexion, and the proximal
end of the volar plate is reattached more proximally to the
metacarpal neck with a suture anchor with enough tension
to maintain the desired degree of flexion. In these cases, a
short-arm thumb spica cast up to the interphalangeal joint
is used for 1 month.
Outcomes
Badia and Sambandam11 recently published results from a
retrospective analysis of 25 assessed patients (26 thumbs)
who underwent the procedure between 1998 and 2003.
Complete pain relief was achieved in 24 patients (96%).
Mild pain was present in 1 patient after traumatic injury to
the hand. Revision of her prosthesis was required for secondary loosening, believed to be caused by the injury.
In that study, preoperative pinch strength was 6 kg in the
noninvolved side and 3.5 kg in the affected thumb (61% from
contralateral side), and postoperative pinch strength was 6.5
kg in the noninvolved side and 5.5 kg in the affected thumb
(85% from contralateral side). Final range of thumb radial
abduction was 60° (range, 50°-65°). Thumb opposition
reached the base of the small finger in all cases.
In addition, radiographs at final follow-up showed no
evidence of implant loosening, cup migration, stem subsidence, or subluxation in both anteroposterior and lateral views
of the thumb. This was also the case for the 1 patient who
underwent joint revision. There were 24 excellent results and
1 good result. The result after the revision was also good.
A. Badia
Conclusions
Careful patient selection, sound implant design, and strict
adherence to surgical technique have been key factors in
successful clinical outcomes of the rarely used procedure
of prosthetic carpometacarpal joint reconstruction of the
thumb. My clinical experience with this procedure has
shown that it is an excellent treatment option for elderly,
low-demand patients who would most benefit from the
advantages described in this article.
Author’s Disclosure Statement
The author wishes to note that he is on the Surgeon
Advisory Board of Small Bone Innovations.
References
1. Tomaino MM. Treatment of Eaton stage I trapeziometacarpal disease with
thumb metacarpal extension osteotomy. J Hand Surg Am. 2000;25(6):11001106.
2. Hartigan BJ, Stern PJ, Kiefhaber TR. Thumb carpometacarpal osteoarthritis: arthrodesis compared with ligament reconstruction and tendon
interposition. J Bone Joint Surg Am. 2001;83(10):1470-1478.
3. Badia A. Trapeziometacarpal arthroscopy: a classification and treatment
algorithm. Hand Clin. 2006;22(2):153-163.
4. Burton RI , Pellegrini VD Jr. Surgical management of basal joint arthritis of
the thumb. Part II. Ligament reconstruction with tendon interposition arthroplasty. J Hand Surg Am. 1986;11(3):324-332.
5. Amadio PC, Millender LH, Smith RJ. Silicone spacer or tendon spacer for
trapezium resection arthroplasty—comparison of results. J Hand Surg Am.
1982;7(3):237-244.
6. de la Caffiniere JY, Aucouturier P. Trapezio-metacarpal arthroplasty by total
prosthesis. Hand. 1979;11(1):41-46.
7. Søndergaard L, Konradsen L, Rechnagel K. Long-term follow-up of
the cemented Caffinière prosthesis for trapezio-metacarpal arthroplasty.
J Hand Surg Br. 1991;16(4):428-430.
8. Alnot JY, Beal D, Oberlin C, Salon A, Guepar. GUEPAR total trapeziometacarpal prosthesis in the treatment of arthritis of the thumb. 36 case reports
[in French]. Ann Chir Main Memb Super. 1993;12(2):93-104.
9. Braun RM. Total joint replacement at the base of the thumb—preliminary
report. J Hand Surg Am. 1982;7(3):245-251.
10. Braun RM. Total joint arthroplasty at the carpometacarpal joint of the
thumb. Clin Orthop. 1985;(195):161-167.
11. Badia A, Sambandam SN. Total joint arthroplasty in the treatment of
advanced stages of thumb carpometacarpal joint osteoarthritis. J Hand
Surg Am. 2006;31(10):1605-1613.
12 Cooney WP III, Chao EY. Biomechanical analysis of static forces in the
thumb during hand function. J Bone Joint Surg Am. 1977;59(1):2736.
August
August 2008
2008 57
A Review Paper
Trapezium-Sparing Options for Thumb
Carpometacarpal Joint Arthritis
Julie E. Adams, MD, Scott P. Steinmann, MD, and Randall W. Culp, MD
Abstract
Thumb carpometacarpal joint arthritis is a common
condition, particularly in middle-aged women. There are
many treatment options, ranging from joint arthroplasty
to arthrodesis to arthroscopic débridement. Trapezium
preservation has been increasingly recognized as desirable for maintaining length of the digit and strength in
pinch and grasp. In this article, we review trapeziumsparing options for treatment of thumb carpometacarpal joint arthritis. These techniques allow surgeons to
recontour or resurface the arthritic joint. Joint stability is
critical to long-term success.
T
humb carpometacarpal (CMC) joint arthritis
is a common complaint, particularly among
women. Initial treatment can involve nonoperative measures, such as activity modification, corticosteroid injections, and splinting.
Operative management may be offered when pain or
functional deficits persist and are recalcitrant to nonoperative means. 1-8
Success rates have been high when partial or complete
trapeziectomy has been used to treat first CMC joint
arthritis.1,2,6,9-11 In the absence of a trapezium, however,
migration of the thumb metacarpal and impingement on
the scaphoid or trapezoid may be a source of pain. In
addition, prolonged recovery is sometimes a problem
with this procedure.9,12 Therefore, it may be desirable,
particularly in the early stages of CMC joint arthritis,
to preserve all or part of the trapezium. Options for the
hypermobile joint (stage 1 disease) include ligament
reconstruction and metacarpal extension osteotomy,
which are not discussed in this article.
Dr. Adams is Hand Surgery Fellow, Philadelphia Hand Center
and Thomas Jefferson University, Philadelphia, Pennsylvania.
Dr. Steinmann is Professor of Orthopedic Surgery, Surgery of the
Hand, Shoulder, and Elbow, Mayo Clinic, Rochester, Minnesota.
Dr. Culp is Hand Surgeon, Philadelphia Hand Center, and
Professor of Orthopedic and Hand Surgery, Thomas Jefferson
University, Philadelphia, Pennsylvania.
Arthroscopic Options
Arthroscopy is a minimally invasive technique that can be
used to diagnose and treat pathology of the thumb CMC
joint.13-16 Arthroscopy has also been used as a diagnostic
staging tool before treatment selection.13,14,17 Patients with
Eaton stage I, II, or III CMC arthritis may be candidates
for arthroscopy to determine the true extent of joint changes. In early stages in which the articular cartilage is intact
but synovitic changes or ligamentous laxity is present,
pathology can be addressed by simple débridement and
capsular shrinkage of the ligaments. Patients with frank
changes, such as attenuation of the anterior oblique liga-
“Because trapezium preservation may be a valid goal for
middle-aged patients with
CMC disease, it is important to
know about these options.”
ment and partial volar cartilage loss, may be candidates
for extension osteotomy or arthroscopic débridement and
interposition arthroplasty, while those with widespread
cartilage loss may do best with arthroscopic débridement
and interposition arthroplasty.14,17
Other authors have described the technique for arthroscopy of the CMC joint.16,18 The thumb is suspended in
traction, and surface landmarks are marked. The joint is
penetrated with a needle; fluoroscopy is helpful to confirm
correct entry to the trapeziometacarpal joint rather than the
scaphotrapezial-trapezoidal joint.
The 2 general portals used are the 1-R (radial) and the
1-U (ulnar) portals (Figure 1). The 1-R portal is made
between the abductor pollicis longus (APL) and flexor
carpi radialis (FCR) tendons at the CMC joint level. It is
best to make this portal closest to the FCR to allow for
ideal triangulation and viewing. The 1-R portal is useful
in examining the dorsal radial ligament, palmar oblique
ligament, and ulnar collateral ligament and provides a
view of the radial aspect of the joint. It also allows for
visualization of the intermetacarpal ligament and the
distal insertions of the anterior oblique ligament into the
first metacarpal.
The 1-U portal is placed just ulnar to the extensor pollicis brevis tendon. Compared with the 1-R portal area, the
1-U portal area can have a higher incidence of superficial
J. E. Adams et al
Figure 1. Drawing of 1-R (radial) and 1-U (ulnar) portals.
Abbreviations: Tm, trapezium; r.a.,
radial artery; EPL, extensor pollicis longus; EPB, extensor pollicis
brevis; APL, abductor pollicis longus; s.r.n., superficial radial nerve;
MI, first metacarpal; MII, second
metacarpal; MIII, third metacarpal. Reproduced from Berger
RA. A technique for arthroscopic
evaluation of the first carpometacarpal joint. J Hand Surg
Am. 1997;22(6):1077-1080, by
permission of Mayo Foundation
for Medical Education and
Research. All rights reserved.
A
A
B
Figure 3. Preoperative (A) and postoperative (B) images after
arthroscopic débridement and interposition arthroplasty demonstrate maintenance of space between the remaining trapezium
and the first metacarpal (B) after resection of the arthritic distal
trapezium (A). Reproduced with permission from Adams JE,
Merten SM, Steinmann SP. Arthroscopic interposition arthroplasty of the first carpometacarpal joint. J Hand Surg Br.
2007;32(3):268-274.
B
Figure 2. A small joint burr is useful in removing the arthritic
distal trapezium (A), which may be done under fluoroscopic
visualization (B).
radial nerve branches crossing the portal site. In addition,
the radial artery is only a few millimeters from the ulnar
side of the portal. Similar to the procedure used for establishing the 1-R portal, the skin is carefully incised, and a
small hemostat is used to gently dissect and spread down
to the capsular tissue, which helps avoid causing traumatic
injury to either branches of the superficial radial nerve or
the radial artery. The 1-U portal tends to enter the joint
either through the dorsal radial ligament or between the
dorsal radial ligament and the palmar oblique ligament.
This portal allows for visualization of the anterior oblique
ligament and the ulnar collateral ligament. It may also be
used as the main working portal for interventions after
diagnostic arthroscopy.18
A standard 1.9-mm arthroscope is used to visualize the
CMC joint. The camera and working portal can be switched
back and forth between the 1-R and the 1-U portals as the
arthroscopy progresses. After diagnostic arthroscopy, the
cautery or radiofrequency ablation probe can be helpful
in débriding the joint of soft tissue. The radiofrequency
ablation probe is useful also for capsular shrinkage when
laxity is present. A small joint shaver (3.5 mm) can be used
August 2008 9
Trapezium-Sparing Options for Thumb Carpometacarpal Joint Arthritis
A
C
Figure 4. The Artelon®
implant (Small Bones
Innovations, Morrisville, PA)
may be placed using an open
(A) procedure or arthroscopic
procedure. Preoperative
(B) and postoperative
(C) images demonstrate a
maintained posthemitrapeziectomy space.
B
to débride the joint further. Visualization is improved with
use of a standard arthroscopic mechanical pump to continuously irrigate the joint with saline. A dedicated outflow
cannula is not needed if both working portals are large
enough to allow egress of fluid.
If bony work after synovectomy or soft-tissue débridement is indicated, a 2.7- or 3.5-mm burr may be used to
remove the distal trapezium (Figure 2A). Care is taken
also to remove bony osteophytes from the volar ulnar edge
of the joint near the second metacarpal. After initial bony
work is done, the arthroscope may be removed and the
burring done under fluoroscopy to ensure adequate removal
of bone (Figure 2B).
After bony recontouring, the joint is then ready for placement of the interposition tissue. Arthroscopic use of autograft tissue, such as half of the FCR or the palmaris longus
tendon, has been described.16,19 Alternatively, a variety of
biologic materials can be processed as interposition materials. Graftjacket® (Wright Medical Technology, Arlington,
TN) is a human dermal matrix that is processed to render
it acellular. Clinical and animal studies suggest it serves as
a scaffold for ingrowth of native cells, and in our series of
patients, outcomes were satisfactory at a mean follow-up of
17 months.15,20 Other choices include a polycaprolactonebased polyurethaneurea implant (Artelon®; Small Bone
Innovations, Morrisville, PA), a novel biomaterial that one
of the authors (RWC) has used successfully in a series of
A
B
Figure 5. Preoperative (A) and postoperative (B) images of pyrocarbon carpometacarpal prosthesis.
patients as a simple interposition material after arthroscopic
débridement. The interposition material can be placed into
the joint with a small curved hemostat through a portal.
The portals are then closed, and a thumb spica splint is
applied. Immobilization is continued for a total of 6 weeks.
Postoperative radiographs are obtained to document maintenance of the postoperative space (Figure 3).
Resurfacing Options
Artelon Resurfacing (Open Procedure)
Nilsson and colleagues21 described using Artelon for interposition arthroplasty of the first CMC joint. As reported,
this implant undergoes slow degradation, which allows it
to serve as a scaffold for ingrowth of cartilage-like tissues.
Use has been investigated in Eaton stage 3 CMC arthritis.
The implant was placed using an open procedure with
minimal (2-mm) trapezium resection (Figures 4A–4C).
Patients who received the implant developed improved
pinch strength relative to preoperative values and relative
to a cohort of patients who underwent trapeziectomy and
APL suspensionplasty. Pain relief was equivalent to that
of the APL group at 3-year follow-up.21 Although the first
studies of this implant were of its use in stage 3 CMC
arthritis—securing a T-shaped device designed to reinforce
ligamentous constraints and to resurface the CMC—there
may be cases in which stability may need to be enhanced
with a tendon transfer. One option is to use a distally based
slip of APL, transferred dorsally, deep to the radial artery,
around or through the extensor carpi radialis longus, and
then back to itself. In addition, it has become clearer with
anecdotal reports that the implant is best secured with
suture or suture anchors rather than with screws, which
may pull through the device.
Pyrocarbon Hemiarthroplasty
Although hemiarthroplasty designs have been commercialized by Ascension Orthopaedics (Austin, TX) and
Nexa/Tornier (San Diego, CA), published reports and valid
outcome studies are lacking. However, anecdotal clinical
reports and the material benefits of pyrocarbon—its favorable wear characteristics and the tolerance of articular
cartilage to the material—support further investigation of
J. E. Adams et al
the merits of these 2 designs. These designs retain stability differently: with a saddle-like lip in the case of the
Ascension implant (Figure 5) or with central recession of
the trapezium in the case of the Nexa device. We have no
personal experience with these implants.
In that trapezium preservation may be a valid goal for
middle-aged patients with CMC disease, it is important to
know about these options. What remains to be seen with
resurfacing using these options, or with using Artelon, is
long-term success.
Salvage and Revision
Because of the novelty of these recontouring and resurfacing procedures, there are few data on salvage in the event
of failure. However, as these procedures are designed to be
less invasive and to preserve the trapezium, revision to more
traditional procedures is possible. Resurfacing arthroplasties
can be readily revised to ligament reconstruction and tendon
interposition, simple trapeziectomy, or fusion.
Conclusions
There are multiple options for treating first CMC joint arthritis.
Procedures that preserve the trapezium may be associated with
improved grip strength and metacarpal length. Arthroscopy is
useful in staging the extent of disease and guiding selection
of treatment options. Satisfactory outcomes occur when these
procedures are performed in the appropriate patient. However,
enthusiasm for these procedures is tempered by the limited
follow-up and outcomes studies available to date.
Authors’ Disclosure Statement
Dr. Adams reports no actual or potential conflict of interest
in relation to this article.
Dr. Steinmann reports a consulting arrangement with
Wright Medical Technology (Arlington, TN).
Dr. Culp reports a consulting arrangement with Small
Bone Innovations (Morrisville, PA).
References
1. Burton RI, Pellegrini VD Jr. Surgical management of basal joint arthritis of the
thumb. Part II. Ligament reconstruction with tendon interposition arthroplasty.
J Hand Surg Am. 1986;11(3):324-332.
2. Burton RI, Pellegrini VD Jr. Basal joint arthritis of thumb. J Hand Surg Am.
1987;12(4):645.
3. Eaton RG, Glickel SZ, Littler JW. Tendon interposition arthroplasty for degenerative arthritis of the trapeziometacarpal joint of the thumb. J Hand Surg Am.
1985;10(5):645-654.
4. Eaton RG, Littler JW. Ligament reconstruction for the painful thumb carpometacarpal joint. J Bone Joint Surg Am. 1973;55(8):1655-1666.
5. Pellegrini VD Jr, Burton RI. Surgical management of basal joint arthritis of the
thumb. Part I. Long-term results of silicone implant arthroplasty. J Hand Surg
Am. 1986;11(3):309-324.
6. Thomsen NO, Jensen CH, Nygaard H. Weilby-Burton arthroplasty of the
trapeziometacarpal joint of the thumb. Scand J Plast Reconstr Surg Hand
Surg. 2000;34(3):253-256.
7. Wilson JN. Basal osteotomy of the first metacarpal in the treatment of arthritis
of the carpometacarpal joint of the thumb. Br J Surg. 1973;60(11):854-858.
8. Wilson JN, Bossley CJ. Osteotomy in the treatment of osteoarthritis of the
first carpometacarpal joint. J Bone Joint Surg Br. 1983;65(2):179-181.
9. Jones NF, Maser BM. Treatment of arthritis of the trapeziometacarpal joint
with trapeziectomy and hematoma arthroplasty. Hand Clin. 2001;17(2):237243.
10. Lins RE, Gelberman RH, McKeown L, Katz JN, Kadiyala RK. Basal joint
arthritis: trapeziectomy with ligament reconstruction and tendon interposition
arthroplasty. J Hand Surg Am. 1996;21(2):202-209.
11. Nylen S, Johnson A, Rosenquist AM. Trapeziectomy and ligament reconstruction for osteoarthrosis of the base of the thumb. A prospective study of
100 operations. J Hand Surg Br. 1993;18(5):616-619.
12. Schroder J, Kerkhoffs GM, Voerman HJ, Marti RK. Surgical treatment of
basal joint disease of the thumb: comparison between resection-interposition
arthroplasty and trapezio-metacarpal arthrodesis. Arch Orthop Trauma Surg.
2002;122(1):35-38.
13. Culp RW, Rekant MS. The role of arthroscopy in evaluating and treating
trapeziometacarpal disease. Hand Clin. 2001;17(2):315-319.
14. Badia A. Trapeziometacarpal arthroscopy: a classification and treatment
algorithm. Hand Clin. 2006;22(2):153-163.
15. Adams JE, Merten SM, Steinmann SP. Arthroscopic interposition arthroplasty
of the first carpometacarpal joint. J Hand Surg Br. 2007;32(3):268-274.
16. Menon J. Arthroscopic management of trapeziometacarpal joint arthritis of
the thumb. Arthroscopy. 1996;12(5):581-587.
17. Badia A, Khanchandani P. Treatment of early basal joint arthritis using a combined arthroscopic débridement and metacarpal osteotomy. Tech Hand Up
Extrem Surg. 2007;11(2):168-173.
18. Berger RA. A technique for arthroscopic evaluation of the first carpometacarpal joint. J Hand Surg Am. 1997;22(6):1077-1080.
19. Menon J. Arthroscopic evaluation of the first carpometacarpal joint. J Hand
Surg Am. 1998;23(4):757.
20. Adams JE, Steinmann SP. Interposition arthroplasty using an acellular dermal
matrix scaffold. Acta Orthop Belg. 2007;73(3):319-326.
21. Nilsson A, Liljensten E, Bergstrom C, Sollerman C. Results from a degradable
TMC joint spacer (Artelon) compared with tendon arthroplasty. J Hand Surg
Am. 2005;30(2):380-389.
August2008
2008 11
9
August
A Review Paper
Amit Gupta, MD, FRCS
Abstract
In the article, I review the history of total wrist arthroplasty designs; give an overview of and design rationale
for the ReMotion (Small Bone Innovations, Morrisville, PA)
total wrist arthroplasty; describe the indications, technique, and postoperative care for this implant; and present some early, very encouraging results.
T
raditional management of wrist arthritis consists of
proximal row carpectomy, partial carpal fusions, or,
in the event of pancarpal arthritis, total wrist fusion.
Although proximal row carpectomy and partial wrist
fusions preserve some motion at the wrist while relieving
pain symptoms, the quality of results obtained from these
procedures is not predictable or optimal in many instances.
Total wrist fusions are credited with universal pain relief at
the expense of wrist motion. However, critical analysis of
the results of total wrist arthrodesis shows that the results are
not always consistent with what has been claimed and that
pain relief is unpredictable at best. In a recent study, 14 of 22
patients who had undergone wrist arthrodesis had residual pain,
and 4 of these patients had severe pain 6 years later.1 In another
study, only 6 of 36 patients remained pain-free 4 years after
wrist arthrodesis.2
Moreover, many patients do not like loss of motion in their
wrists. In a study of wrist arthrodesis, only 40% of patients
were satisfied at 1 year.3 In another study, 100% of patients
who had wrist arthrodesis indicated that they would have a
procedure performed so they could move their wrists again.1
Management of hip, knee, ankle, and shoulder joints has
evolved from arthrodesis to arthroplasty. The wrist joint
awaits the same pattern of evolution with the advent of reliable designs.
Historical Overview
Since the early 1970s, investigators have sought a reliable total
wrist implant design that would produce consistent results. The
Swanson4 1-piece silicone elastomer implant design, though
not a true total arthroplasty, was certainly a step in the direction
of providing motion to the wrist while relieving pain. Despite
good early results, implant breakage and subsidence required
many revisions.
Dr. Gupta is Clinical Associate Professor, Department of
Orthopedic Surgery, University of Louisville, Louisville, Kentucky,
and Director, Louisville Arm and Hand, Louisville, Kentucky.
The first true arthroplasty of the wrist was designed by
Mueli.5 This ball-and-socket design has 2 long prongs cemented into the metacarpals and had required a fairly large resection
of the distal radius, including resection of the distal radioulnar
joint, to cement the radial component. This design had many
complications, including imbalance, loosening, and implant
fracture. After undergoing multiple modifications to correct the
problems, the design was finally discontinued.
The Mueli implant was contemporaneous with the Volz6
implant. The Volz implant had an anteroposterior toroidal grooved
polyethylene radial component sitting on a metal-backed radial
component and an articulating metal implant cemented to the
second and third metacarpals with 2 metal prongs. Similar to the
“In another study, 100%
of patients who had wrist
arthrodesis indicated that
they would have a procedure performed so they could
move their wrists again.1”
Mueli design, it required a large amount of bone resection for
insertion. Despite promising early results, this implant also was
associated with high rates of loosening and was withdrawn.
The next significant wrist arthroplasty was the biaxial
implant.7 This design had evolved to an ellipsoidal metal distal component cemented to the third metacarpal with a long
stem. This articulated with a metal-backed polyethylene radial
component that was fixed to the radius with cement. Despite
extensive bone resection required to implant the device, most
of the problems with this implant were related to the distal
component. Carpal loosening, metacarpal fractures, imbalance,
and implant subsidence resulted in many revisions and conversions to wrist arthrodeses. Although in the designer’s hands the
results were fairly good (Kaplan-Meier probability of revisionfree survival at 6.5 years, 83%; no pain to mild pain in 94% of
patients8), there were reports of many failures. Design modifications followed. In an effort to decrease the long moment arm
of the distal component in the third metacarpal, the length of
the distal part was reduced. Despite these efforts, the complication and revision rates of this implant were unacceptable, and
the implant was finally withdrawn.
The trispherical total wrist arthroplasty (TWA) had a brief
run.9 Again, the implant had early good results in the designer’s
hands. In one study of 38 arthroplasties, all patients were
“improved by the implants.”
A. Gupta
Figure 1. The amount of bone resected to insert the ReMotion
(Small Bone Innovations, Morrisville, PA) total wrist arthroplasty
is minimal.
Since in wrist arthroplasties the carpal side appeared to be the
major problem because of loosening and imbalance, Menon10
decided to keep all fixations in the carpus and the base of the
metacarpals in his Universal Total Wrist Implant. This was a
3-piece design with the carpal component screwed to the distal
carpal row with provision for intercarpal fusion. The radial
component was made of cobalt-chromium (CoCr) and was
cemented into the radius. Between the 2 components was a
convex ultrahigh-density polyethylene component attached to
the carpal plate and articulated with the radial component in
a toroidal articulation. Because of the toroidal articulation, the
design was inherently unstable, and early dislocation was a
significant problem.11 However, Menon10 had shown very good
Figure 2. Carpal plate and rotating polyethylene ellipse.
Designs that converted the wrist joint into a hinge joint decreased
degrees of freedom, leading to increased transmission of stress
to the metal–bone interface and loosening. Furthermore, a successful wrist arthroplasty design must have enough intrinsic
stability to allow the muscle tendon units to function normally
and not require a period of immobilization for that to happen. It
has been clearly demonstrated that the ellipsoidal design articulating with a “cup” achieves this aim.
The other aspect of a stable joint involves the surrounding
ligaments. In most wrist arthroplasty designs to date, a segment
of the distal radius, often a large segment, is excised. Doing that
renders all wrist ligaments nonfunctional. So, the ideal wrist
arthroplasty design must preserve the rim of the distal radius
where the ligaments are attached. There are 2 other advantages
“In TWA design, the most important consideration is stability.
If the joint is not stable, it cannot provide pain-free function.”
results with his wrist implant, with 89% of patients pain-free at
42 months. The complication rate was high (25.5%), and dislocations occurred in 14% of cases.
After an elegant finite element analysis that concluded that
ellipsoidal implants were inherently more stable than toroidal
implants,11 Grosland and colleagues modified the Menon
design to the Universal 2 design incorporating the changes.
The design changes have led to a reduction in the number of
dislocations.
Design Rationale of ReMotion
I now describe the design considerations of the ReMotionTM
(Small Bone Innovations, Morrisville, Pa) TWA. In TWA
design, the most important consideration is stability. If the
joint is not stable, it cannot provide pain-free function. The
best definition of stability is “control of degrees of freedom.”
Past designs that made the wrist into a ball-and-socket design
increased degrees of freedom. In an arthritic wrist with poor
neuromuscular control, this increase often proved catastrophic.
to this action. First, the proprioceptive properties of the wrist
ligaments are maintained, which helps in the neuromuscular
control of the wrist joint and gives the patient the impression
of normal joint motion. Second, when the distal radius is not
excised, the distal radioulnar joint (DRUJ) and the triangular
fibrocartilage complex are preserved. It is particularly important
to preserve the integrity and stability of the DRUJ, especially
when the DRUJ is uninvolved in the disease process.
Avoiding resection of the distal radius also achieves another
goal: minimal bone resection. Not only does minimal bone
resection contribute to stability, but it preserves bone for
future reconstruction or salvage, planning for which is vital in
implant design. In the design being described, the bone resection amount is minimal (Figure 1). Only half of the scaphoid,
triquetrum, and lunate is excised, leaving substantial bone mass
for arthrodesis between the distal carpal row and the radius in
the event of implant failure.
Minimal bone resection should be combined with avoiding
use of cement in the implant arthroplasty of the wrist. In the
wrist and hand, cement use has not been successful over the
August 2008 13
Figure 3. All components.
Figure 4. Radial component with undercut volar side.
long term. In the current wrist arthroplasty design, efforts have
been made to avoid using bone cement. The carpal plate is made
of CoCr with commercially pure titanium coating to encourage
bone ingrowth. The central stem of the carpal component is
press-fit into the capitate (Figure 2). Efforts have also been made
to limit carpal fixation to the carpus and base of the metacarpals
and to avoid any long-lever arms by having long stems extending into the metacarpal shafts. The central peg inserts into the
capitate and may cross the third carpometacarpal (CMC) joint
into the base of the third metacarpal. Two screws compress the
carpal plate to the cut end of the carpus and fix the plate to the
hamate on one side and the scaphoid, trapezoid, and base of the
second metacarpal on the other. This pattern of carpal fixation,
along with packing the remaining carpal interstices with cancellous bone taken from the resected proximal carpal row or radius,
results in the carpal side being converted into a solid bony mass
by intercarpal fusion. Carpal fixation is thus enhanced, as is
uniform load transmission. I have not observed any case of carpal loosening with this implant. The specially designed 4.5-mm
CoCr alloy screws with wide cancellous pitch form provide firm
fixation in the cancellous bone. These screws can be angled 30°
for versatility in fixation.
The distal carpal row has an inherent arch. If a straight carpal
plate were to be screwed into this arched articulation, it would
flatten the carpal curvature, resulting in tendonitis and neuritis by
irritation of the contents of the carpal tunnel. Avoiding this eventuality involves offsetting the 2 screw holes palmar to the central peg
of the carpal plate such that the carpal curvature is maintained.
The next design feature unique to this implant is that it provides an ultrahigh-density polyethylene ellipse that rotates on
the carpal plate (Figure 2). This ellipse, snap-fit on a ball on
the proximal side of the carpal plate, can rotate 10° relative to
the carpal plate and in doing so acts as a dampener and avoids
torque transmission to the metal carpus component. We believe
that this feature also preserves the complex “dart thrower’s”
motion of the wrist with relative axial rotation between the
intercalated segment and the carpal plate.
The proximal component of this implant is a moderately deep
ellipse cup that approximates anatomical centers of rotation
with an anatomically shaped intramedullary stem (Figure 3).
The radial component is made of CoCr and has a commercially
pure titanium coating. This implant is press-fit into the radius,
the rim of which is preserved. If necessary, impact grafting may
be added to enhance the radius fixation. Certain features of the
radial component should be discussed. The articulating part of
the radius has 10° of palmar tilt to match the native radius. It has
10° of radioulnar inclination. The palmar surface of the radial
cup is undercut to prevent median nerve or tendon impingement
(Figure 4).
This implant has been tested extensively in the laboratory.
Wear and fatigue testing was performed at the Mayo Clinic
Biomechanics Laboratory. The primary parameters for wear testing were constant compressive load of 20 lb (89 N); articulation
in a 40° conical range of motion (ROM); and 5 million cycles
in bovine environment at 37°C. The secondary parameters for
wear testing were constant compressive load of 20 lb (89 N),
articulation in a 10° reciprocating ROM; and 5 million cycles in
bovine environment at 37°C. Results showed that there was mild
evidence of wear and cold flow, but there were no statistically
significant changes in gravimetric or dimensional characteristics.
The fatigue testing parameters were sinusoidal load of 0 to 20
lb (89 N); fixed flexion angle of 45°; and 5 million cycles in
bovine environment at 37°C. Results showed that there was mild
evidence of wear and cold flow, but there were no statistically
significant changes in gravimetric or dimensional characteristics.
This implant is designed to provide 40° of flexion, 40° of
extension, and 30° arc of radial/ulnar deviation (Figures 5, 6).
Since its release for general use in 2002, there have been no
major design modifications. Recently, a very small section of
material was removed from the dorsoradial portion of the radial
component for better fit. The implant is available in 3 sizes:
small, medium, and large. An extra-small size is being added.
The polyethylene ellipse is available in standard size and in a
“plus” size that adds 1 mm to the height of the ellipse, enhancing stability.
Indications
The major indication of TWA is rheumatoid arthritis.
Traditionally, wrist arthroplasty is recommended for rheumatoid
wrists when wrist damage is extensive and there are severe bone
A. Gupta
Figure 5. Right wrist extension 1 year after total wrist
arthroplasty in a rheumatoid
patient with bilateral wrist
involvement.
Figure 6. Right wrist flexion
1 year after total wrist arthroplasty in a rheumatoid patient
with bilateral wrist involvement.
loss and gross soft-tissue imbalances. These situations set up the
arthroplasty for failure. For a successful arthroplasty, good bone
stock and soft-tissue balance are essential.
Osteoarthritis is a good indication for wrist replacement, as
there usually are good bone stock and soft tissues. Indications will
increase in number when TWA results become predictable.
Posttraumatic arthritis is a controversial indication for wrist
arthroplasty, as there are more “conservative” options, like limited wrist fusions. However, the quality of results of wrist arthroplasty surpasses that of 4-corner fusion and scaphoid excision.
More controversial indications are failed proximal row carpectomies and failed 4-corner fusions. As TWAs become commonplace, young patients with wrist arthrodesis will demand
“takedown” of their fusion and conversion to wrist arthroplasty.
Technique
The insertion is done with a dorsal longitudinal approach. Two
retinacular flaps are elevated, one based on the radial side and
the other ulnarly. A distally based dorsal capsular flap is elevated. Now precision guided technology instruments are used
to accurately insert the implant, particularly to precisely center
the capitate/third metacarpal axis to the central longitudinal axis
of the radius. The lunate spacer is inserted into the lunate fossa
and is used to assemble and position the radial block over the
Lister’s tubercle. The radial block is fixed to the radius with 2
thick Kirschner wires (K-wires) that are bent out of the way. The
radiolucent marker is fixed to the radial block, and the wrist is
imaged in 2 planes to confirm that the marker is aligned to the
long axis of the radius in both planes. Now the carpal cutting
guide is assembled into the radius block, and the distal “tang”
is positioned over the third metacarpal. The carpus is resected
along the guide, taking care not to damage the palmar capsule.
The cutting guide and the resected carpals (part of the scaphoid,
lunate, and triquetral) and the tips of the capitate and hamate
are removed, and the burr guide is inserted into the radial block.
Next, the articular surface of the radius is contour-burred after
hyperflexing the wrist. The burring removes the articular cartilage and exposes the subchondral bone. The burr guide is now
removed, and the radial drill guide is inserted into the radius
block. The radial drill guide is appropriately positioned, and a
2-mm threaded pin is inserted into the medullary canal of the
radius. Imaging is done in 2 planes. Once the pin is positioned
in the central part of the radial medullary canal, the radial
drill guide and radial block are removed, and the cannulated
broaches of appropriate size are mounted over the pin, and the
radius is broached. Once the broaching is complete, a trial radial
component is inserted.
The carpal side is now addressed. The trial radial component
is removed, the wrist is hyperflexed, and the carpal drill guide
is aligned over the capitate with the tang aligned to the third
metacarpal. The carpal post is drilled with a 2-mm wire. The
position is confirmed with imaging. The drill guide is removed,
and the capitate is broached to the appropriate size. Now the
trial carpal and radial components are impacted in. At this point,
if the distal scaphoid appears too loose, a K-wire can be used
to stabilize it to the capitate. If, as is usually the case, the distal
triquetral is outside the carpal plate, it should be excised. Trial
reduction is performed. If the joint appears too loose, a plus-size
polyethylene ellipse is selected. The definitive radial component
is impacted in, with some impact grafting if necessary. The carpal component is inserted into the capitate, and the screw drill
guides are used to aim the drill for the second metacarpal on
the radial side and the fourth metacarpal on the ulnar side. After
the screw lengths are measured, screws are inserted. The ulnar
screw should not cross the CMC joint and should remain in the
hamate. The radial screw crosses the second CMC joint, and
the tip is positioned ideally in the base of the second metacarpal
(Figure 7). While the screws are being tightened sequentially,
care is taken to avoid rotating the carpal plate. Now an appropriate polyethylene insert is snap-fit into the carpal ball, and
the joint is reduced. The wrist is imaged in 2 planes to confirm
proper insertion of the components. At this point, a small osteotome is used to remove some of the cartilage between the capitate and the hamate and other carpal bones, and these spaces are
packed with cancellous graft harvested from the excised carpus.
The dorsal capsule is repaired with nonabsorbable sutures. The
radially based retinacular flap is positioned over the capsule to
prevent any portion of the metal radial rim from abrading the
extensor tendons. The ulnar based retinacular flap is closed over
all the extensor tendons except the extensor pollicis longus,
which is left in an extra-retinacular position. Now the tourniquet
is released, hemostasis obtained, and skin closure performed in
routine fashion. The wrist is put in a well-padded plaster splint
and kept well elevated during the postoperative period.
In special situations, modifications are needed. For rheumatoid wrists with bone loss, it may be necessary to cross the
CMC joints with the central carpal peg and the 2 carpal screws.
For bone deficiency, extra bone grafting may be necessary.
For poor bone quality, I recommend using a small amount of
cement with the radial and carpal components. For soft-tissue imbalance, tendon transfers may be necessary at time of
arthroplasty. For capsular deficiency, the palmar capsule may
be reinforced with cadaveric fascia lata or Graftjacket (Wright
Medical Technology, Arlington, TN). The dorsal capsule can be
reconstructed with a retinacular flap.
In revising a failed proximal row carpectomy to wrist arthroplasty, it is first necessary to obtain sufficient “space” for the
August
August 2008
2008 13
15
DASH (Disabilities of the Arm, Shoulder, and Hand) score was
83 (range, 60-113), while DASH score at 1 year was 61 (range,
28-121). There was no radiologic loosening at 1 year.
Similar results were obtained at the Mayo Clinic (W. P.
Cooney, MD, oral communication, October 2007). Twentyseven patients (18 with rheumatoid arthritis, 9 with posttraumatic
arthritis) had been followed up for more than 1 year. There were
no major complications at follow-up, except 1 patient who had
flexor carpi radialis tendonitis. Mean ROM was 50° extension,
45° flexion, and 43° radioulnar deviation.
Figure 7. Radiograph of left total wrist arthroplasty shows radial
screw crossing second carpometacarpal joint and ulnar screw
in the hamate.
implant. After the joint is exposed, 2 laminar spreaders are used
to distract the carpus from the radius. This maneuver may also
be necessary in conversion of a wrist arthrodesis to arthroplasty.
In failed proximal row carpectomy and failed scapholunate
advanced collapse revisions, the missing scaphoid can be
replaced by harvesting the pisiform through a separate palmar
incision. With the pisiform held in the space normally occupied
by the scaphoid, the radial carpal screw is inserted. In all these
situations, the dorsal capsule should be reconstructed with a
retinacular flap.
Postoperative Care
The patient comes to the office 5 to 7 days after surgery. If the
swelling is manageable, an orthoplast splint is fashioned for
the wrist and finger motion, and gentle active wrist motions are
encouraged. Formal physical and occupational therapy with
digital motion, wrist motion, and edema-reducing protocols is
started 10 days to 2 weeks after surgery. It typically takes 4 to 6
months to gain optimal ROM and strength.
Outcomes
In 2007, Sollerman and colleagues12 reported preliminary results
from a multicenter prospective study they had begun of this
implant in Sweden and Denmark in 2004. Their plan was to
use standardized measurements to study 60 patients with the
implant for 5 years. There were 57 enrolled patients (12 men,
45 women). Mean age was 61 years (range, 30-82 years). Fortyeight patients had rheumatoid arthritis, 4 had osteoarthritis, 4 had
posttraumatic arthritis, and 1 had Kienbock disease. Of these 48
patients, 22 reached the 1-year follow-up. No complications were
seen at 1 year. All but 1 patient reported improved function and
less pain. Mean ROM was 56° (range, 30°-135°). Preoperative
Summary and Conclusions
I have given an overview of and the design rationale for the
ReMotion TWA and provided some early, very encouraging
results. In designing this joint, I believe we have clearly thought out
many of the problems associated with TWAs, have incorporated the
lessons of history, and have taken into account the recent biomechanical studies on the wrist joint and implant arthroplasty.
Bunnell wrote, “A painless stable wrist is the key to hand
function.” Up until now, to make the wrist stable, we have had
to make it stiff too. But this does not have to be the case. The
bar for functional motion at the wrist is very low. As estimated
by Palmer and colleagues,13 a functional wrist requires only 30°
extension, 5° wrist flexion, 10° radial deviation, and 15° ulnar
deviation. The question in 2008 is: Can we consistently and
safely provide such ROM to our patients’ wrists without resorting to a destructive procedure like wrist fusion? With improvements in design and long-term results showing that these
designs work, indications for wrist arthrodesis will decrease and
those for wrist arthroplasty will increase.
and Acknowledgments
The author wishes to note that he has an ongoing relationship
with Small Bone Innovations. The author would like to thank
David Liebel for engineering input in the design of the implant.
References
1. Adey L, Ring D, Jupiter JB. Health status after total wrist arthrodesis for posttraumatic arthritis. J Hand Surg Am. 2005;30(5):932-936.
2. De Smet L, Truyen J. Arthrodesis of the wrist for osteoarthritis: outcome with a
minimum follow-up of 4 years. J Hand Surg Br. 2003;28(6):575-577.
3. Rauhaniemi J, Tiusanen H, Sipola E. Total wrist fusion: a study of 115 patients. J
Hand Surg Br. 2005;30(2):217-219.
4. Swanson AB. Flexible implant arthroplasty for arthritic disabilities of the radiocarpal joint. A silicone rubber intramedullary stemmed flexible hinge implant for the
wrist joint. Orthop Clin North Am. 1973;4(2):383-394.
5. Mueli HC. Mueli total wrist arthroplasty. Clin Orthop. 1984;(187):107-111.
6. Volz RG. Total wrist arthroplasty: a new approach to wrist disability. Clin Orthop.
1977;(128):180-189.
7. Beckenbaugh RD. Total joint arthroplasty. The wrist. Mayo Clin Proc.
1979;54(8):513-515.
8. Cobb TK, Beckenbaugh RD. Biaxial total-wrist arthroplasty. J Hand Surg Am.
1996;21(6):1011-1021.
9. Figgie HE 3rd, Ranawat CS, Inglis AE, Straub LR, Mow C. Preliminary results
of total wrist arthroplasty in rheumatoid arthritis using the trispherical total wrist
arthroplasty. J Arthroplasty. 1988;3(1):9-15.
10. Menon J. Universal Total Wrist Implant: experience with a carpal component
fixed with three screws. J Arthroplasty. 1998;13(5):515-523.
11. Grosland NM, Rogge RD, Adams BD. Influence of articular geometry on prosthetic wrist stability. Clin Orthop. 2004;(421):134-142.
12. Sollerman C, Ibsen A, Boeckstyns M, Kopylov P, Kroemer K, Petterson K.
One year result from an on-going multicenter study of the Avanta wrist implant.
Abstract presented at: Meeting of the International Federation of Societies for the
Surgery of the Hand; March 2007; Sydney, Australia.
13. Palmer AK, Werner FW, Murphy D, Glisson R. Functional wrist motion: a biomechanical study. J Hand Surg Am. 1985;10(1):39-46.
®
16
American Journal
of Orthopedics
14 The
A Supplement
to The American
Journal
of Orthopedics®
A Review Paper
Indications for Ulnar Head Replacement
Abstract
Implanting an endoprosthesis is a clinically proven means of reestablishing mechanical contact
between the distal radius and ulna, thus providing the foundation for stability of the entire forearm.
The indications for, contraindications to, and outcomes
of ulnar head replacement are discussed, together with
the underlying mechanics, pathomechanics of ulnar
head excision, the theoretical basis for implant arthroplasty, and the designs that have been employed.
H
istorically, resection of the ulnar head has been an
accepted treatment for painful arthrosis of the distal
radioulnar joint. Although patients can be satisfied with the result, painful convergence instability
is a common outcome. Attempts to counter such instability
with soft-tissue procedures have been largely unsuccessful.
Implantation of an endoprosthesis is a clinically proven means
of reestablishing mechanical contact between the distal radius
and ulna, thus providing the foundation for stability of the
entire forearm joint. Implants have been based on hemiprosthesis, multicomponent unconstrained surface replacement arthroplasty, or semiconstrained total joint arthroplasty designs.
Anatomy
The ulnar head forms the distal end of the ulna. Under normal circumstances, it articulates with the medial surface of
the distal radius and provides attachments for the soft tissues
that contribute in no small part to the stabilization of the distal radioulnar joint (DRUJ) and the ulnocarpal relationship.
The ulnar head can be further divided into bony regions,
namely, the styloid process and the seat. The ulnar styloid
process is a cylindrical projection along the posterior cortex
extending distally a variable distance from the head. The seat
of the ulna is a cylindrical expansion formed by the distal
epiphysis of the ulna. Approximately two thirds of the seat is
covered by articular (hyaline) cartilage for articulation with
the sigmoid notch throughout the range of forearm pronation and supination, as well as interfacing with the proximal
surface of the triangular disc of the triangular fibrocartilage
Dr. Berger
Orthopedic
Fellowship,
Education,
Minnesota.
is Professor and Consultant, Departments of
Surgery and Anatomy, Director, Hand Surgery
and Dean, Mayo School of Continuing Medical
College of Medicine, Mayo Clinic, Rochester,
complex (TFCC). Between the base of the styloid process
and the set of the ulna is a depression, the fovea, which is a
key attachment point for stabilizing soft tissues.
Mechanics
Hagert1 reminded us that the DRUJ is merely part of the
overall forearm joint, which is essentially a bicondylar
joint. The axis of rotation of the forearm passes obliquely
through the forearm from the radial head proximally
through the ulnar head distally.2 Forearm rotation occurs
about this axis in a manner that pivots the radius around
the fixed ulna—which necessitates a gliding motion
through the DRUJ, combining rotation and translation.
“...the main indication for
implanting an ulnar head
endoprosthesis or semiconstrained DRUJ endoprosthesis
is painful instability after
resection of the ulnar head.”
This motion is facilitated by a differential radius of curvature between the sigmoid notch and the ulnar head (larger
vs smaller radius of curvature, respectively).
DRUJ constraints, which have been studied extensively,
include static and dynamic stabilizers. The primary constraints of the DRUJ are found in the TFCC as the dorsal
and palmar radioulnar ligaments. These ligaments attach
to the radius at the margins of the sigmoid notch and
converge to form a single attachment at the fovea. There
are several different interpretations of the position- and
motion-direction–specific roles of these ligaments, but it
is clear that the integrity of both ligaments is a requisite
for a stable DRUJ.3-5 The DRUJ joint capsule is an important stabilizer of the DRUJ, most evident in positions of
extreme pronation and supination. The entire soft-tissue
envelope of the ulnar side of the distal forearm and wrist
forms an important secondary stabilizer, as does the
interosseous membrane. Finally, merely having contact
between the ulna and the radius through the DRUJ has
been shown to generate up to approximately 30% of the
total constraint of the DRUJ.5 As long as the ulnar head
is in contact with the sigmoid notch, the muscles that
cross the axis of forearm rotation stabilize the forearm and
DRUJ by compressing the ulnar head to the radius within
the arc of the sigmoid notch.
August 2008 17
Indications For Ulnar Head Replacement
Pathomechanics of Ulnar Head Excision
When the ulnar head is removed, the foundation of the
DRUJ undergoes alterations. The radius and ulna are
“uncoupled,” creating an intrinsically unstable construct.
No longer is the radius in contact with the ulna, and therefore there is a complete loss of the “up to 30%” constraint
created simply by having the radius and ulna in contact
with each other. There is a disruption of soft-tissue attachment of the TFCC and DRUJ joint capsule with excavation
of the bony support for the soft-tissue envelope of the distal
forearm and ulnar wrist, as already noted. The dynamic stabilizers are unopposed in their action to draw the radius and
ulna together, resulting in convergence instability and loss
of tension in the interosseous membrane, further destabilizing the forearm joint.6
“...removal of a nonarthritic
ulnar head for treatment
of ‘ulnar wrist pain’ should
be avoided...”
Theoretical Rationale of
Implant Arthroplasty
There is no doubt that resection of the ulnar head (Darrach
resection) or creation of a distal diaphyseal pseudarthrosis with fusion of the ulnar head to the radius (SauvéKapandji procedure) can result in clinical success, as noted
extensively in the literature. These procedures have been
shown to be efficacious in patients with intractable pain
for arthrosis and complications resulting from caput ulnae
syndrome. However, most patients dramatically alter use
patterns after such procedures and are limited by painful
convergence instability. Interestingly, though grip strength
has been shown to improve after ulnar head resection under
appropriate conditions, little is known about the effects on
torque strength.
The rationale for implantation of an endoprosthetic
ulnar head is based on the need for direct contact between
the distal ulna and the radius, which completes the
mechanical linkage of the forearm joint. Attempts to use
soft-tissue procedures to stabilize the forearm joint after
ulnar head resection have been found to be mechanically
ineffective7 because of the inability to create a soft-tissue stabilizing procedure based on a vector that holds
the radius and ulna apart. Thus, the principal purpose
of implanting an ulnar head endoprosthesis is simply to
hold the diaphyses of the distal radius and ulna apart.6,8
This process retensions the interosseous membrane, counters the converging tendencies of the dynamic forearm
stabilizers, restores improved muscle tension profiles,
reestablishes a stable architecture for the axis of rotation,
and provides the endoskeletal support for the envelope of
soft tissues associated with the ulnar aspect of the distal
forearm and the ulnocarpal joint.
Design
Ulnar head endoprostheses can be divided into unconstrained and semiconstrained categories. Unconstrained
prostheses can be further grouped into hemiarthroplasty and total (surface replacement) arthroplasty designs.
Unconstrained prostheses are designed to simulate characteristics of the natural ulnar head; they separate the radius
and ulna and provide a convex articular surface for contact
with the sigmoid notch. At the same time, unconstrained
implants depend on soft-tissue stabilization to keep the
ulnar head in contact with the sigmoid notch.
Hemiarthoplasty implants make contact directly with
the native sigmoid notch. Each device is implanted into
the medullary canal of the distal ulna through a stem or
shaft. Universally, but with minor variations, a soft-tissue envelope is developed, creating essentially a soft-tissue socket around the semispherical head to stabilize the
implant relative to the radius. Ulnar head endoprostheses
vary in their design characteristics, including full-radius
curvature, partial radius curvature, centered alignment of
the head on the shaft, and eccentric alignment of the head
on the shaft. It has been shown in the laboratory that the
full radius head with centered alignment is efficacious in
restoring normal kinematics and stabilizing characteristics
of the forearm joint.6,8 No studies have shown any change
in these results with introduction of alternative designs.
The various materials that have been used range from silicone rubber, pyrolytic carbon, ceramic, and cobalt-chrome.
Silicone rubber has been withdrawn from use because of
an unacceptable fracture rate and incidence of particulate
silicone synovitis.
Recently, a sigmoid component designed to interface
as a surface replacement arthroplasty with an ulnar head
endoprosthesis was introduced. This design is based on a
metal backing secured to the distal radius and a high-density polyethylene (HDPE) wafer integrated into the metal
back. The concave curvature of the HDPE wafer matches
the curvature of the ulnar head implant. Again, creating a
soft-tissue envelope around the construct is necessary for
stability.
An alternative to implant arthroplasty for stabilizing
the forearm joint is the semiconstrained design, in which
radial and ulnar components are connected through a sliding gimbal that allows rotation and translation sufficient for
forearm rotation. Because the radius and ulna are linked,
the need for soft-tissue stabilization is minimized. Rather,
the soft-tissue envelope is used to provide coverage for the
implant from the overlying extrinsic tendons.
Indications
An obvious prerequisite for implantation of an endoprosthetic ulnar head is a missing native ulnar head. If there is
pain, and lack of an ulnar head is its root cause, implantation of the endoprosthesis should be considered. Typically,
instability related to loss of constrained contact between
the distal radius and distal ulna is found to be the root cause
of the pain. Although anterior–posterior instability of the
R. A. Berger
Figure 1. Preoperative anteroposterior film.
Figure 2. Postoperative anteroposterior film.
radius on the ulna can be painful, it more typically results
in a conscious sense of instability and weakness, sometimes
accompanied by a clicking sensation. Some describe this
as “piano key” or “shuck” instability. What is more often
an actual cause of pain is contact between the stump of the
ulna and the distal radius, that is, convergence instability.
Convergence instability typically has presented as
increasing pain with simply bearing a load in the hand
when the forearm is parallel to the ground in a neutral
rotation position. Gravity-induced convergence is essentially created between the hand–wrist–radius unit and the
fixed ulna. In the clinic, the distal ulna and radius can be
squeezed together to try to recreate the patient’s pain and
demonstrate convergence instability. Radiographs can also
confirm the presence of convergence instability, though
they are not pathognomonic. There may be excessive tapering of the distal end of the ulna, and there may be a depression formed in the medial cortex of the radius at the point of
contact between the tip of the ulna and the radius.
Thus, the main indication for implanting an ulnar head
endoprosthesis or semiconstrained DRUJ endoprosthesis
is painful instability after resection of the ulnar head.
Instability alone, without pain, can also be a valid indication at the discretion of the surgeon in careful consideration
of the functional expectations of the patient. The procedure
can be considered for all resection conditions, including
Darrach resection, Sauvé-Kapandji pseudarthrosis, and
even some wide ulnar excision situations. Excessive loss of
ulnar length may compromise the ability to secure a proper
fit of the ulnar component.
This procedure can be performed either as a revision
after a failed resection arthroplasty or as a primary procedure the same time that a resection arthroplasty is being
performed (Figures 1, 2). Given the inherent instability
after resection of the distal ulna, in patients with degenerative arthritis of the ulnar head or sigmoid notch, I typically
plan on performing an immediate endoprosthesis implantation as a primary procedure unless it is contraindicated. It
is indicated for any type of arthritic condition, though when
there is significant ongoing inflammation with soft-tissue
involvement, medical management should be optimized
before prosthetic implantation is considered. In my experience, endoprosthesis implantation in a very limited number of patients with marginally controlled inflammatory
arthropathy has had limited success because of progressive
loss of soft-tissue stabilization.
Painful convergence instability can occur as frequently
with a Sauvé-Kapandji procedure as with an ulnar head
resection because of the same mechanical uncoupling
noted earlier. Endoprosthetic options can be divided into
maintaining the ulnar head in situ and excising the ulnar
head. For maintaining the ulnar head in situ, implanting an
endoprosthesis into the pseudarthrosis has been reported,
but this procedure would be limited to using an implant
that has either a convex distal geometry for stable articulation with the neck of the ulna or the ability to rotate at
the head–stem interface. Excision of the ulnar head can
be revised to an implant arthroplasty using either a semiconstrained implant or a hemiarthroplasty. However, it is
advised that, when revising a Sauvé-Kapandji procedure
August 2008 19
Indications For Ulnar Head Replacement
to an implant arthroplasty, use of the hemiarthroplasty
technique should also involve implantation of a sigmoid
component. The reason is that, with excision of the ulnar
head, cancellous bone within the region of the previous
sigmoid notch is exposed because the subchondral bone
of the sigmoid notch was likely excised during preparation for the ulnar head fusion procedure. The mismatch of
hardness of the ulnar head endoprosthesis and the cancellous bone may predispose to subsidence of the endoprosthesis into the distal radial epiphysis, undermining the
cancellous bone supporting the lunate fossa.
revision. One comforting fact is that if indeed the implant
must be removed (for whatever reason) and if the procedure
is performed properly, then the patient will be left with a
resection arthroplasty, no worse of a situation than what he
or she would have experienced having undergone a primary
procedure without implant arthroplasty.
Contraindications
1. Hagert CG. The distal radioulnar joint in relation to the whole forearm. Clin
Orthop. 1992;(275):56-64.
2. Tay SC, van Riet R, Kazunari T, et al. A method for in-vivo kinematic analysis
of the forearm. J Biomech. 2008;41(1):56-62
3. Haugstvedt JR, Berger RA, Berglund LJ, Neale PG, Sabick MB. An analysis
of the constraint properties of the distal radioulnar ligament attachments to
the ulna. J Hand Surg Am. 2002;27(1):61-67.
4. Haugstvedt JR, Berger RA, Nakamura T, Neale P, Berglund L, An KN.
Relative contributions of the ulnar attachments of the triangular fibrocartilage complex to the dynamic stability of the distal radioulnar joint. J Hand
Surg Am. 2006;31(3):445-451.
5. Stuart PR, Berger RA, Linscheid RL, An KN. The dorsopalmar stability of
the distal radioulnar joint. J Hand Surg Am. 2000;25(4):689-699.
6. Sauerbier M, Hahn ME, Fujita M, Neale PG, Berglund LJ, Berger RA.
Analysis of dynamic distal radioulnar convergence after ulnar head resection and endoprosthesis implantation. J Hand Surg Am. 2002;27(3):425434.
7. Sauerbier M, Berger RA, Fujita M, Hahn ME. Radioulnar convergence after
distal ulnar resection—mechanical performance of two commonly used soft
tissue stabilizing procedures. Acta Orthop Scand. 2003;74(4):420-428.
8. Masaoka S, Longworth SH, Werner FW, Short WH, Green JK. Biomechanical
analysis of two ulnar head prostheses. J Hand Surg Am. 2002;27(5):845853.
9. van Schoonhoven J, Fernandez DL, Bowers WH, Herbert TJ. Salvage of
failed resection arthroplasties of the distal radioulnar joint using a new ulnar
head prosthesis. J Hand Surg Am. 2000;25(3):438-46.
10. Willis AA, Berger RA, Cooney WP. Arthroplasty of the distal radioulnar joint
using a new ulnar head endoprosthesis: preliminary report. J Hand Surg
Am. 2007;32(2):177-189.
Contraindications, the same as with any other implant,
include active infection, insufficient soft-tissue coverage,
insufficient muscle control of the forearm joint, lack of predictable gain of function as a result of the procedure (including likely severe limitation for forearm motion), excessive
loss of ulnar length, and other considerations, including
patient compliance, comorbidities, and unrealistic expectations of outcomes. It cannot be overemphasized that removal
of a nonarthritic ulnar head for treatment of “ulnar wrist pain”
should be avoided and cannot be justified simply because
there are now adequate endoprosthetic implants available.
These implants do not create a normal joint and should not
be expected to. Removing a nonarthritic ulnar head is seldom
justified.
Outcomes
Although silicone rubber implants had their problems,
newer implants are showing great promise. Because of
space limitations, I refer the reader to the relevant original
articles.9,10 Very few complications have been reported
with the implants. Residual pain, instability, and loosening
have all been reported but seldom have required surgical
The author wishes to note that he is a co-holder of the patent
on the uHeadTM Ulna Head Implant (SBI, Morrisville, PA).
20
References
A Review Paper
Radial Head Fractures and the Role of Radial
Head Prosthetic Replacement: Current Update
William P. Cooney, MD
Abstract
Radial head fractures are often secondary to a direct
axial force, such as that involved in motor vehicle
accidents and falls on an outstretched hand. The
Hotchkiss-modified Mason classification is an excellent
assessment tool in that it provides commonly accepted
direction regarding treatment. For more unstable, comminuted displaced radial head fractures that cannot be
reconstructed, replacement of the radial head is warranted. The surgeon should attempt open reduction
and internal fixation with restoration of the radial head
in anatomical alignment for most type II and some type
III fractures, and this treatment is recommended over
radial head resection without replacement, as the latter
is associated with both elbow and forearm instability
over the long term and should be avoided. New radial
head replacement designs, including bipolar designs
and radial head and capitellar replacements, are available but have limited reported clinical results.
F
ractures of the radial head are either simple,
straightforward isolated fractures or more complex fractures associated with elbow and forearm
instability.1-3 The elbow is a basic hinge joint,
wherein the radial head has an important role as a stabilizer on the lateral aspect of the elbow and is important
in elbow and forearm motion as a key component of the
radiocapitellar joint. The radial head works in concert with
essential anatomical stabilizers of the elbow. These structures include not only the radial head, but the capitellum,
coronoid process, ulnohumeral joint, and associated lateral
ulnohumeral ligament, medial ulnohumeral ligament, and
olecranon.4 The proximal radioulnar joint is stabilized by
the lateral ulnohumeral ligament and the annular ligament
(Figure 1). When a “simple” radial head fracture is associated with one or more of these key essential functional
components of the elbow—in particular, with the coronoid
process or the medial or lateral ulnohumeral ligament—it
assumes a different personality and ultimately requires a
different type of treatment. 3,5-8
Radial head fractures were classified by Mason9 in 1954
and modified by Hotchkiss1 in 1997 (Figure 2; Table). This
Dr. Cooney is Professor Emeritus, Department of Orthopedic
Surgery, Mayo Clinic, Rochester, Minnesota.
classification provides a reasonable approach to diagnosing and treating radial head fractures.
Type I radial head fractures (minimally displaced) are
usually simple, straightforward fractures secondary to a
longitudinal compressive force, and usually they are not
associated with injuries to the other essential anatomical
support structures.
Type II radial head fractures (moderately displaced) are
articular fractures of the radial head or angulated fractures
of the radial head and proximal shaft or neck area (Figure
3). These are often caused by a combination of axial and
rotational forces and may be most commonly associated
with a fall on the outstretched hand and a resulting wrist
injury. With type II injuries, it is important to check not
only for injuries of the essential anatomical structures (eg,
coronoid process), but also for wrist or forearm injuries
associated with the axial directed force, particularly injuries to the distal radioulnar joint.10-16
Type III radial head fractures, comminuted fractures
of the radial head, are often associated with injury to the
other essential anatomical support elements of the elbow
(medial collateral ligament, coronoid process, capitellum)
(Figure 4). With type III fractures, usually the elbow (and
the forearm) is determined to be stable.
Type IV radial head fractures involve a comminuted
radial head fracture and elements of elbow and/or forearm instability.1,9,17 Careful examination of the elbow,
for example, will demonstrate instability often associated
Figure to Come
Figure 1. Anatomy of ligament support of elbow; lateral collateral ligament complex. Reprinted from: Morrey
BF. “Anatomy of elbow.” In:
The Elbow and Its Disorders.
3rd ed. Philadelphia, PA: W.
B. Saunders; 2000:figure 228. Copyrighted and used
with permission from Mayo
Foundation
for
Medical
Education and Research.
Figure 2. Mason classification
of radial head fractures: type I,
undisplaced; type II, displaced;
type III, comminuted and displaced; type IV, comminuted
and displaced with elbow or
forearm instability (discs 1001,
7000). Reprinted from: Morrey
BF. “Radial head fractures.” In:
The Elbow and Its Disorders.
3rd ed. Philadelphia, PA: W.
B. Saunders; 2000:figure 25-4.
Copyrighted and used with permission from Mayo Foundation
for Medical Education and
Research.
August 2008 21
Radial Head Fractures and the Role of Radial Head Prosthetic Replacement
A
Figure 3. Clinical example of Mason type II fracture (disc
3001).
A
Figure 4. Clinical example
of Mason type III/IV fracture
(disc 24001).
B
Figure 6. (A) Preparation for internal fixation with provision of
Kirschner wire and countersunk drill followed by screw insertion.
(D) Radiograph of Herbert screw fixation of radial head. Reprinted
from: Morrey BF. “Radial head fractures.” In: The Elbow and Its
Disorders. 3rd ed. Philadelphia, PA: W. B. Saunders; 2000:figure 2517. Copyrighted and used with permission from Mayo Foundation for
Medical Education and Research. [FIGURE TO BE CORRECTED]
B
Figure 5. (A) Displaced type II radial head fracture with failed
closed reduction (disc 21001). (B) Open reduction and compression-screw fixation along with proximal radius plate.
with dislocation of the elbow and a radial head fracture.
One or more of the essential elements is often injured.
These complex radial head fractures require different treatment recommendations. Again, it is essential to examine
the elbow as well as the wrist and forearm for associated
injuries at the elbow—in particular, for olecranon fractures,
coronoid process fractures, and medial or lateral collateral
ligament injuries.
Diagnosis
Clinical examination of the elbow and wrist is essential
when there is a history of a substantial force or fall on the
outstretched hand or forearm, and it provides the initial key
to diagnosis. Tenderness, swelling over the lateral aspect of
the elbow, and painful forearm or elbow motion are often
present. Motion of the forearm and elbow may be limited.
The interosseous membrane within the midforearm may
demonstrate tenderness. The essential anatomical structures
about the elbow should be carefully examined for, specifically, stability in extension and flexion (medial and lateral
ulnohumeral ligaments) and tenderness (along the olecranon
and over the radial head and ulnohumeral joint). Gentle
stress testing of the elbow for instability (particularly valgus
instability) should be performed. Forearm range-of-motion
(ROM) and rotation limitations caused by pain should be
noted. Wrist examination includes careful assessment of the
distal radioulnar joint for fracture and/or instability.
Imaging assessment includes plain anteroposterior and
lateral radiographs along with varus and valgus stress films.
Radiographs of the forearm and distal radioulnar joint and
wrist should be included as well. Tomogram radiographs
of the elbow are becoming increasingly important in determining degree of displacement of a radial head fracture
and any associated injuries, particularly of the coronoid
process, capitellum, or proximal ulna.1,3,7,18-20 Fractures
of the coronoid process, for example, are classified into 3
types based on degree of injury seen on lateral tomogram
A
B
Figure 7. (A) Silicone implant (disc 25001) with stem loosening
and early silicone synovitis. (B) Monoblock radial head replacement with long stem and bone cement.
radiographs. Three-dimensional tomographic reconstruction has provided an even clearer view of the degree of
injury and potential instability of the elbow associated with
radial head fractures.
Treatment
Treatment of radial head fractures fits well with the
Mason–Hotchkiss classification and is recommended.
Nondisplaced or minimally displaced Mason type I radial
head fractures may be treated with supportive splinting and
early ROM.1,7,20,21 Aspiration of the elbow hematoma may
be beneficial, along with an injection of analgesic medication, such as lidocaine or bupivacaine. With the assistance of
therapy, assisted ROM can be performed, but any evidence of
instability should be carefully considered.
Type II radial head fractures include displacement of
the radial head and are treated by open reduction and
internal fixation (Figure 5). Current recommended treatment is lateral Kocher approach to the elbow, exposure of
the radial head, placement of stabilizing Kirschner wires
(K-wires), and placement of cannulated screws over the Kwires1,7,20,22,23 (Figure 6). Headless screws (preferred) are
countersunk in the radial head and exiting proximal to the
proximal radioulnar joint,10,24 which prevents injury and
subsequent arthritis of the proximal radioulnar joint from a
prominent radial head screw. However, if it is necessary to
have the screw cross the radial head transversely, care must
be taken to avoid penetration of the far cortex.23 Laterally
placed small plates may be considered, but these are often
associated with loss of forearm rotation and inability to
repair the annular ligament.1,22,23 Several recently developed small, low-profile plates may be of benefit, but these
have not been presented in any type of clinical series. For
type II injuries, the lateral approach is usually preferred;
W. P. Cooney
Table. Mason Classification as Modified by Hotchkiss1
Type
Description
I
II
III
IV22
Minimally displaced fracture, no mechanical block to forearm rotation, intra-articular displacement less than 2 mm
Fracture displaced more than 2 mm or angulated, possible mechanical block to forearm rotation
Severely comminuted fracture, mechanical block to motion
Radial fracture with associated elbow dislocation
a recently described posterior approach allows for more
direct access to associated structures about the elbow. This
approach, described by King25 and Ring and King,2 helps
prevent indirect injury to the lateral ulnohumeral ligament
and provides options for repair of that structure when it is
associated with radial head fractures.
Mason type III radial head fractures are comminuted
fractures that usually require excision or, preferably, radial
head replacement. Studies have demonstrated that, after
resection of the radial head, these fractures cause long-term
axial instabilities because of lack of support on the lateral
aspect of the elbow.10,11,15,25-27 The radial head serves as
a secondary stabilizer of the elbow and also of the forearm. Loss of the radial head leads to unstable forearm
force transmission and an altered center of rotation for
the forearm. Current options for radial head replacement
include silicone spacers and metallic implants (metallic
implants can be spacers or true anatomical radial head
replacements).2,7,8,12,28-34 Currently, there is less indication
A
or recommendation for use of a silicone implant because
of problems with silicone synovitis8 (Figure 7). We therefore recommend a radial head implant that can be either
cemented or left uncemented in place depending on the
technique used. Both monoblock and bipolar prostheses
are available2,7,28,29,32-34 (Figures 8–9). There is no clinical
series showing a preference for monoblock over bipolar.
With a bipolar prosthesis (Figure 8), it is argued that the
radial head can seat itself more anatomically on the capitellum, but if a monoblock prosthesis of appropriate size
is used for a radial head replacement, particularly in acute
trauma, and there is minimal associated lateral collateral
ligament injury, one can anticipate satisfactory long-term
results. The debate over cemented versus uncemented/freefloating radial head implants has not been resolved. It has
been suggested that free-floating implants (Figure 9) also
allow better seating with the capitellum.12,32,35
The Essex-Lopresti lesion is an axial forearm instability
usually associated with comminuted and displaced radial
head fractures. This lesion is classified as a Mason type
IV injury,12,15 which is an unstable fracture associated
with elbow instability or axial forearm instability. Mason
type IV injuries commonly present as complex elbow
injuries, often described as a terrible triad of injury to the
medial collateral ligament, the coronoid process, and the
radial head. With these fractures, a posterior approach is
recommended, along with repair of the medial collateral
ligament, repair of the coronoid process, and replacement
of the radial head.5,13,22,27,29 Radial head implants provide
a secondary stabilizer to the elbow and are recommended
in the treatment of instability of the elbow associated with
radial head fractures.
B
Figure 8. (A) Monoblock modular design and (B) bipolar radial
head implant design (Small Bone Innovations, Morrisville, PA).
Surgical Technique
With radial head fractures, plate fixation or prosthetic replacement is performed from a lateral approach between the anconeus and the extensor carpi ulnaris.36 This approach can be
extended 5 to 6 cm more proximally along the lateral column
A
Figure 9. Evolve modular, monoblock radial head design. Photo
provided by Wright Medical Technology, Inc.
B
Figure 10. (A) Failed internal fixation plate of proximal radius
fracture (disc 29001) and (B) radial head replacement with repair
of ulnar humeral ligament (disc 30001) with Mitek anchors.
August 2008 23
Radial Head Fractures and the Role of Radial Head Prosthetic Replacement
of the elbow, which allows for better visualization and release
of the anterior and posterior capsules. With this approach, the
extensor carpi radialis longus and brevis muscles are released
and retracted anteriorly while the extensor carpi ulnaris and
anconeus muscles are reflected posteriorly from the lateral
epicondyle. The lateral collateral ligament is reflected from
the lateral epicondyle with important preservation of the lateral ulnohumeral ligament. For radial head replacement, the
radial head is excised at the level of the radial neck, preserving the annular ligament. We recommend using an alignment
guide. After division across the radial neck, the radial head is
excised and used as a template for the size of the radial head
implant. The proximal radius is then broached and the radial
stem inserted along the intramedullary canal prepared by the
broach. The radial implant is then placed on the stem; a firm
fit is obtained with most of the implants. Lateral closure is
performed in layers repairing the annular ligament and lateral
collateral ligaments. Radiographic confirmation of alignment
and position of the radial head implant with respect to the
capitellum in flexion, extension, and pronosupination is
important to ensure proper contact with the capitellum and
overall alignment. (Surgical technique details: http://www.
totalsmallbone.com/us/pdfs/rHead_RadialSurgical.pdf.)
Late Elbow Instability
With radial head fractures, late presentation of elbow instability also requires consideration of radial head replacement.34
Alternatives for radial instability have in the past included fascial or muscle interposition arthroplasties, such as the anconeus muscle or a silicone implant (Figures 7A, 7B). Today, we
more commonly recommend a radial head implant with either
a bipolar or monoblock radial head replacement. When there
are late problems of arthritis or osteopenia of the capitellum
caused by unloading, radial head capitellar replacement may
be considered in addition to radial head replacement.
Perils and Pitfalls
In the treatment of radial head fractures, the surgeon should
consider several potential problems. First, all bone and softtissue stabilizers of the elbow—including the radial head capitellum, the coronoid process, the olecranon, and the medial
and lateral collateral ligaments—should be considered part
of the injury.6,14,19,27 With careful clinical and radiographic
examination, injuries to these stabilizers can be confirmed.
The second consideration is that radial head repair may fail
and that radial head replacement is a viable option in such
cases (Figure 10). It is also essential to repair the coronoid
process and the olecranon in anatomical alignment and in
combination with repair or replacement of the radial head.
With radial head implants, it is important not to “overstuff”
the lateral side of the elbow with the radial head implant, as
doing so can place excessive pressure on the radiocapitellar joint. The radial head implant should match the level of
articulation of the proximal ulna with the distal humerus. In
an acute fracture, the radial head implant should be sized
to match the excised radial head. Length of the radial head
should be judged by normal anatomy and proximal displace-
ment when the distal radius is forcefully loaded from a distal
direction to a proximal direction. When there is a question,
a smaller rather than a larger radial head implant should be
selected. Options for the radial head implant include bone
fixation, bone cement, and free-floating radial head stem. We
prefer an osteointegration implant system.
Use of a hinged brace or an external fixator37 may be necessary in certain unstable elbow dislocations associated with a
radial head fracture and injury to the medial collateral ligament
and coronoid process. In such cases, early elbow ROM can be
initiated using an anatomically aligned external fixator.
Treatment Results
In 1981, Swanson and colleagues17 reported results from their
study of silicone radial head implants. Twelve patients with late
silicone replacement of the radial head and 6 patients with acute
replacement (follow-up, 3.8 years) demonstrated the value of
radial head replacement in providing elbow stability after both
acute and chronic cases of radial head fracture. The value of
a secondary stabilizer with good radiocapitellar contact and
ability to prevent radial shortening was noted. However, results
from later studies of silicone radial head replacement showed
problems of implant instability and silicone synovitis.
Radial head metal implants soon replaced silicone implants.
In 2001, Moro and colleagues14 reported their experience with
a metallic radial head implant in 24 consecutive patients with
unreconstructible fractures of the radial head. Described patients
had Mason type III and IV injuries, usually associated with other
injuries, including coronoid and collateral ligament injuries. As
graded on the Mayo Elbow Performance Index (MEPI), there
were 17 good to excellent, 5 fair, and 3 poor results. Disabilities of
Arm, Shoulder, and Hand scores were 17±19, and Short Form–36
Health-Related Quality of Life scores were 47±10. Fair and poor
results were associated with concomitant associated injuries,
work compensation issues, and litigation. Results from objective
studies showed elbow motion of 9° to 140°, forearm pronation of
78°, and supination of 68°. With use of a modular, free-floating
intramedullary stem, Moro and colleagues noted asymptomatic
loosening around the implant in 17 of 25 elbows. They concluded
that a metal radial head implant for severely comminuted radial
head fractures was safe and effective but resulted in mild to moderate physical limitations of the elbow.
In 2004, Ashwood and colleagues28 reported their experience with a titanium prosthesis for Mason type III radial
head fractures. Sixteen patients had titanium prosthetic
replacement alone or with medial collateral ligament repair.
There were 8 excellent, 5 good, and 3 fair Mayo Wrist
scores. The patients treated acutely fared better than those
treated with late reconstruction. Elbow motion was restored
along with elbow and forearm stability, with slight loss of
elbow extension and forearm rotation. Ashwood and colleagues concluded that monoblock radial head replacement
along with soft-tissue reconstruction helped restore stability, and they emphasized early mobilization.
Longer term evaluation of radial head implants was performed by Shore and colleagues34 in a review of 32 metallic radial head implants. Indications for replacement were
®
22 The
A Supplement
to The American
Journal
of Orthopedics®
24
American Journal
of Orthopedics
W. P. Cooney
delayed union and nonunion of radial head fractures, elbow
instability, failed radial head excision, and silicone radial
head implants. There were 17 excellent and 8 good results
(64%) and 7 fair and 4 poor results; mean MEPI score was
83 points on a 0-to-100 scale (100 being ideal). Patients had
less motion and strength in the affected elbow than in the
unaffected elbow. No prosthesis required revision, but 74%
showed some degree of posttraumatic arthritis. Metallic
implants appear to be safe and durable at 8-year follow-up,
but longer term outcomes are guarded.
Delayed treatment of chronic longitudinal radioulnar dissociation associated with comminuted radial head fractures
was reviewed by Hejink and colleagues.12 Eight patients had
chronic axial or longitudinal deficiency treated with a metal
radial head implant. Four patients were doing well a mean
of 6 years (range, 4.4-7.4 years) after primary implantation;
the other 4 patients showed mild evidence of aseptic loosening (1 metal radial head was revised to a bipolar implant).
Mild degenerative changes in the capitellum were found in 2
patients, and another 2 patients required capitellum replacement. Mean Mayo Wrist score was 70 points, and mean MEPI
score was 78.8 points (out of 100) with 2 excellent, 2 good,
3 fair, and 1 poor overall final results. The good and excellent
results were associated with a bipolar prosthetic design and the
fair and poor results with a monoblock radial head implant.
Summary
Radial head fractures are often secondary to a direct axial
force, such as that involved in motor vehicle accidents and
falls on an outstretched hand. The Hotchkiss-modified Mason
classification is an excellent assessment tool in that it provides commonly accepted direction regarding treatment. For
more unstable, comminuted displaced radial head fractures
that cannot be reconstructed, replacement of the radial head
is warranted. The surgeon should attempt open reduction and
internal fixation with restoration of the radial head in anatomical alignment for most type II and some type III fractures,
and this treatment is recommended over radial head resection
without replacement, as the latter is associated with both
elbow and forearm instability over the long term and should
be avoided. New radial head replacement designs, including
bipolar designs and radial head and capitellar replacements,
are available but have limited reported clinical results.
The author wishes to note that he has a consulting contract
with Small Bone Innovations and receives royalties through
the Mayo Clinic.
References
1. Hotchkiss RN. Displaced fractures of the radial head: internal fixation or
excision? J Am Acad Orthop Surg. 1997;5(1):1-10.
2. Ring D, King G. Radial head arthroplasty with a modular metal spacer to
treat acute traumatic elbow instability. Surgical technique. J Bone Joint
Surg Am. 2008;90(suppl 2):63-73.
3. Sotereanos DG, Darlis NA, Wright TW, Goitz RJ, King GJ. Unstable fracture-dislocations of the elbow. Instr Course Lect. 2007;56:369-376.
4. Van Riet RP, Morrey BF, O’Driscoll SW, Van Glabbeek F. Associated injuries
complicating radial head fractures: a demographic study. Clin Orthop.
2005;(441):351-355.
5. Charalambous CP, Stanley JK, Siddique I, Powell E, Ramamurthy C, Gagey
O. Radial head fracture in the medial collateral ligament deficient elbow;
biomechanical comparison of fixation, replacement and excision in human
cadavers. Injury. 2006;37(9):849-853.
6. Doornberg JN, Ring DC. Fractures of the anteromedial facet of the coronoid process. J Bone Joint Surgery Am. 2006;88(10):2216-2224.
7. Jackson JD, Steinmann SP. Radial head fractures. Hand Clin.
2007;23(2):185-193.
8. Morrey BF, Askew L, Chao EY. Silastic prosthetic replacement for the radial
head. J Bone Joint Surg Am. 1981;63(3):454-458.
9. Mason ML. Some observations on fractures of the head of the radius with
a review of one hundred cases. Br J Surg. 1954;42(172):123-132.
10. Broberg MA, Morrey BF. Results of delayed excision of the radial head after
fracture. J Bone Joint Surg Am. 1986;68(5):669-674.
11. Essex-Lopresti P. Fractures of the radial head with distal radio-ulnar dislocation; report of two cases. J Bone Joint Surg Br. 1951;33(2):244-247.
12. Heijink A, Cooney WP, Morrey BF. Metal radial head replacement for chronic
longitudinal radio-ulnar disassociation. J Shoulder Elbow Surg. In press.
13. Calfee R, Madom I, Weiss AP. Radial head arthroplasty. J Hand Surg Am.
2006;31(2):314-321.
14. Moro JK, Werier J, MacDermid JC, Patterson SD, King GJ. Arthroplasty
with a metal radial head for unreconstructible fractures of the radial head. J
Bone Joint Surg Am. 2001;83(8):1201-1211.
15. Rozental TD, Beredjiklian PK, Bozentka DJ. Longitudinal radioulnar dissociation. J Am Acad Orthop Surg. 2003;11(1):68-73.
16. Van Riet RP, Van Glabbeek F, Neale PG, et al. Anatomical considerations of
the radius. Clin Anat. 2004;17(7):564-569.
17. Swanson AB, Jaeger SH, La Rochelle D. Comminuted fractures of the
radial head. The role of silicone-implant replacement arthroplasty. J Bone
Joint Surg Am. 1981;63(7):1039-1049.
18. Caputo AE, Burton KJ, Cohen MS, King GJ. Articular cartilage injuries of
the capitellum interposed in radial head fractures: a report of ten cases. J
Shoulder Elbow Surg. 2006;15(6):716-720.
19. Ring D. Fractures of the coronoid process of the ulna. J Hand Surg Am.
2006;31(10):1679-1689.
20. Tejwani NC, Mehta H. Fractures of the radial head and neck: current concepts in management. J Am Acad Orthop Surg. 2007;15(7):380-387.
21. Wysocki RW, Cohen MS. Surgical management of radial head fractures.
Am J Orthop. 2007;36(2):62-66.
22. Lindenhovius AL, Felsch Q, Doornberg JN, Ring D, Kloen P. Open reduction and internal fixation compared with excision for unstable displaced
fractures of the radial head. J Hand Surg Am. 2007;32(5):630-636.
23. McArthur RA. Herbert screw fixation of fracture of the head of the radius.
Clin Orthop. 1987;(224):79-87.
24. Bunker TD, Newman JH. The Herbert differential pitch bone screw in displaced radial head fractures. Injury. 1985;16(9):621-624.
25. King GJ. Management of comminuted radial head fractures with replacement arthroplasty. Hand Clin. 2004;20(4):429-441.
26. Cebesoy O, Baltaci ET, Isik M. Importance of radial head on elbow kinematics: radial head prosthesis. Arch Orthop Trauma Surg. 2006;126(7):501.
27. Harrington IJ, Tountas AA. Replacement of the radial head in the treatment
of unstable elbow fractures. Injury. 1981;12(5):405-412.
28. Ashwood N, Bain GI, Unni R. Management of Mason type-III radial head
fractures with a titanium prosthesis, ligament repair, and early mobilization.
J Bone Joint Surg Am. 2004;86(2):274-280.
29. Bain GI, Ashwood N, Baird R, Unni R. Management of Mason type-III
radial head fractures with a titanium prosthesis, ligament repair, and early
mobilization. Surgical technique. J Bone Joint Surg Am. 2005;87(suppl 1,
pt 1):136-147.
30. Brinkman JM, Rahusen FT, de Vos MJ, Eygendaal D. Treatment of sequelae
of radial head fractures with a bipolar radial head prosthesis: good outcome
after 1-4 years follow-up in 11 patients. Acta Orthop. 2005;76(6):867-872.
31. Chapman CB, Su BW, Sinicropi SM, Bruno R, Strauch RJ, Rosenwasser
MP. Vitallium radial head prosthesis for acute and chronic elbow fractures
and fracture-dislocations involving the radial head. J Shoulder Elbow Surg.
2006;15(4):463-473.
32. Dotzis A, Cochu G, Mabit C, Charissoux JL, Arnaud JP. Comminuted fractures of the radial head treated by the Judet floating radial head prosthesis.
J Bone Joint Surg Br. 2006;88(6):760-764.
33. Grewal R, MacDermid JC, Faber KJ, Drosdowech DS, King GJ. Comminuted
radial head fractures treated with a modular metallic radial head arthroplasty. Study of outcomes. J Bone Joint Surg Am. 2006;88(10):2192-2200.
34. Shore BJ, Mozzon JB, MacDermid JC, Faber KJ, King GJ. Chronic posttraumatic elbow disorders treated with metallic radial head arthroplasty. J
Bone Joint Surg Am. 2008;90(2):271-280.
35. Judet T, Garreau de Loubresse C, Piriou P, Charnley G. A floating prosthesis for radial-head fractures. J Bone Joint Surg Br. 1996;78(2):244-249.
36. Mansat P, Morrey BF. The column procedure: a limited lateral approach for
extrinsic contracture of the elbow. J Bone Joint Surg Am. 1998;80(11):16031615.
37. De Llano Temboury AQ, Arévalo RL, Queipo de Lllano Jiménez FL. ARM:
a modular hinged joint for the AO tubular external fixator. Tech Hand Up
Extrem Surg. 2006;10(1):14-24.
August 2008
2008 23
25
August

American Journalof Orthopedics

Transcription

Similar documents

Examination of Hand and Wrist

Kenda - Bearclaw HTR - Modern Tire Company

g-Force T/A Drag Radial

Penny-Power-7-IMPLANT-SEM

Silimed cover 6page

Hand Differences in Fanconi Anemia

Fracture in Upper Extremity2558

Entrapment Neuropathies &amp

Cateterismo Cardíaco por vía Radial