O Foot and ankle Percutaneous screw fixation for fractures of the

Transcription

O Foot and ankle Percutaneous screw fixation for fractures of the
Foot and ankle
Percutaneous screw fixation for fractures of the
sesamoid bones of the hallux
C. M. Blundell, P. Nicholson, M. W. Blackney
From the Monash Medical Centre, Clayton, Australia
ver a period of one year we treated nine fractures of
the sesamoid bones of the hallux, five of which were
in the medial sesamoid. All patients had symptoms on
exercise, but only one had a recent history of injury. The
mean age of the patients was 27 years (17 to 45) and
there were six men. The mean duration of symptoms was
nine months (1.5 to 48). The diagnosis was based on
clinical and radiological investigations. We describe a
new surgical technique for percutaneous screw fixation
for these fractures using a Barouk screw.
All the patients were assessed before and after
surgery using the American Orthopaedic Foot and
Ankle Society Hallux Score (AOFAS). There was a
statistically significant improvement in the mean score
from 46.9 to 80.7 (p = 0.0003) after fixation of the
fracture with a rapid resolution of symptoms. All
patients returned to their previous level of activity by
three months.
We believe that this relatively simple technique is an
excellent method of treatment in appropriately selected
patients.
O
J Bone Joint Surg [Br] 2002; 84-B:1138-41.
Submitted: 5 December 2001; Accepted: 12 April 2002
Fractures of the sesamoids are one of many conditions
which can present in the metatarsal region with disabling
pain related to exercise. The symptoms can be devastating,
particularly to a high-performance athlete.1 An accurate
diagnosis should be based on thorough clinical examination
and radiological investigations.
C. M. Blundell, FRCS (Trauma & Orth), Foot and Ankle Fellow
P. Nicholson, FRCS Orth, Fellow
M. W. Blackney, FRACS, Consultant Orthopaedic Surgeon
Department of Orthopaedics, Monash Medical Centre, 246 Clayton Road,
Clayton, Victoria 3168, Australia.
Correspondence should be sent to Mr C. M. Blundell at 44 Christchurch
Road, Norwich, Norfolk NR2 3NE, UK.
©2002 British Editorial Society of Bone and Joint Surgery
0301-620X/02/813064 $2.00
1138
The optimal management of these fractures is unclear,
and patients are often initially treated conservatively,2,3 with
methods which include strapping, immobilisation in a cast,
orthotics, steroid injections and modification of activity. If
the symptoms fail to settle, surgical alternatives may be considered, particularly in high-performance athletes.1,4 These
include total or partial excision of the sesamoid or bone
grafting of nonunion.1,2,4,5 The uncertain outcome following these procedures led us to look for an alternative treatment.
We now describe a new technique of percutaneous screw
fixation of fractures of the sesamoid bones of the hallux.
Patients and Methods
We have treated nine fractures of the sesamoid bones of the
hallux by percutaneous fixation. In all patients the fracture
was in the sagittal plane, i.e. transverse to the tendon of
flexor hallucis brevis, and comminution was minimal. Seven
were high-performance athletes (Table I) and five competed
at interstate or national level. Their mean age was 27 years
(17 to 45) and there were six men. They complained of pain
of gradual onset on the plantar aspect of the first metatarsophalangeal joint on exercise. In only one patient was
there a previous history of injury. The mean duration of
symptoms was nine months (six weeks to four years). The
median duration was three months.
The patients were assessed using the American Orthopaedic Foot and Ankle Society Hallux Score (AOFAS)
(Table II)6 and the mean preoperative score was 46.9 (25 to
64). Seven graded their pain as severe and two as moderate.
Clinical examination revealed tenderness over the symptomatic sesamoid, with no restriction of movement. Pain was
elicited in all patients on forced dorsiflexion of the great toe.
Plain radiographs, including the contralateral foot, were
taken to exclude bilateral developmental lesions of the sesamoids. Anteroposterior (AP), lateral and axial weight-bearing views were obtained. In addition, all patients had a
technetium bone scintigram and four had MRI and one CT.
There was a fracture of the medial sesamoid in five
patients and of the lateral sesamoid in four. In none were the
fragments widely displaced. All patients had had a previous
course of conservative treatment which failed including one
or more of rest, orthotics, immobilisation in a cast, physioTHE JOURNAL OF BONE AND JOINT SURGERY
PERCUTANEOUS SCREW FIXATION FOR FRACTURES OF THE SESAMOID BONES OF THE HALLUX
Table I. The activities of the patients
Activity
Number
Hockey*
AFL football*
Badminton*
Dancing
PE teacher
Labourer
Student
2
2
1
1
1
1
1
*national/interstate level
therapy, oral analgesics, oral non-steroidal anti-inflammatory drugs and cortisone injections.
Operative treatment. The procedure is carried out as a day
case under general anaesthesia. No tourniquet is required.
The patient is placed supine on a radiolucent operating table
to allow access for an image intensifier. The great toe is
strapped in maximal dorsiflexion before cleansing over the
tape and draping the foot (Fig. 1a). This position stabilises
the sesamoids and renders them more superficial. Axial and
lateral views are obtained using the image intensifier.
A stab incision is made over the distal part of the affected
sesamoid. A 1 mm guide wire is inserted under radiological
control into the axial and lateral mid-diameter of the sesamoid (Fig. 1b). Through the same incision a second wire of
the same length is inserted and positioned at the distal
cortex of the sesamoid. By comparing the protruding
lengths of the wires a screw of appropriate size is selected.
A 2 mm cannulated drill is inserted over the guide-wire and
both cortices drilled.
A self-tapping Barouk screw (DePuy International,
Leeds, UK) is inserted from distal to proximal in order to
engage both cortices for maximal compression. The distal
thread should be buried within the sesamoid (Fig. 2). Steristrip is applied to the skin and a light dressing applied.
Postoperatively, patients are mobilised with two crutches
for one week, bearing weight as tolerated. They are then
allowed to bear weight fully without aids. Running is
allowed at six weeks with a gradual return to full activity at
three months.
Results
There were no intraoperative failures of insertion of the
screw and no wound complications. At review at three
months, five patients had regained full movement of their
first metatarsophalangeal joint and four had mild stiffness.
All patients had dramatic relief from pain. Five were painfree and four had only mild, occasional pain. Because of
compression of the fracture it was not possible to confirm
union radiologically. The reduction of both the activityrelated pain and tenderness at the site of the fracture indicated that bony stability had been achieved. The mean
AOFAS improved from 46.9 before to 80.7 after operation,
which was statistically significant (paired Student’s t-test, p
VOL. 84-B, No. 8, NOVEMBER 2002
1139
= 0.0003). At six months after surgery, all patients had
returned to their preinjury recreational and sporting level of
activity and had had no complications.
Discussion
The sesamoids have a vital role in the dynamics of the great
toe since they act as a fulcrum to increase the mechanical
advantage of the tendon of flexor hallucis brevis. They also
absorb weight-bearing forces from the metatarsal head. The
great toe complex transmits more than 50% of the bodyweight on exercise.7 The sesamoids are thus subjected to
significant forces on impact loading and shear which make
them susceptible to acute and stress fractures and possible
subsequent nonunion.
Fractures of the sesamoids are initially treated conservatively.2,3 If symptoms fail to settle, surgery may be
required. The uncertain outcome following excision of a
Table II. The AOFAS for grading clinical results before and after percutaneous screw fixation for fractures of the sesamoid bones of the hallux
Score
Pain (40 points)
None
Mild, occasional
Moderate, daily
Severe, almost always present
Function (45 points)
Activity limitations (10 points)
No activity limitations
No limitations of daily activities such as employment
responsibilities, limitation of recreational activities
Limited daily and recreational activities
Severe limitation of daily and recreational activities
40
30
20
0
10
7
4
0
Footwear requirements (10 points)
Fashionable, conventional shoes, no insert required
Comfortable footwear, shoe insert
Modified shoes or brace
10
5
0
MTP joint motion (dorsiflexion plus plantar flexion)
Normal or mild restriction
Moderate restriction
Severe restriction
10
5
0
IP joint motion (plantar flexion)
No restriction
Severe restriction (less than 10˚)
5
0
Great toe stability (5 points)
Stable
Grossly unstable (floppy)
5
0
Great toe callus (5 points)
Absent
Present
5
0
Alignment (15 points)
Good
Fair
Poor
15
8
0
1140
C. M. BLUNDELL, P. NICHOLSON, M. W. BLACKNEY
Fig. 1a
Fig. 1b
Photograph showing the great toe dorsiflexed with tape.
A lateral view showing the guide-wire used to aid insertion of the percutaneous screw.
Fig. 2b
Fig. 2a
AP (a) and lateral (b) radiographs taken after surgery showing the position
of the screw.
sesamoid1,5 has led to more conservative procedures such
as partial sesamoidectomy2 and bone grafting of nonunions.1,4 Wound complications are, however, common
after these open procedures.
The assessment and accurate diagnosis of the cause of
sesamoid pain and subsequent management are a challenge for the orthopaedic surgeon. Differential diagnoses
include acute fractures, nonunion and stress fractures.
Histological examination of 32 sesamoids excised for
pain showed that in 28 there was an ununited fracture,
suggesting that fractures are an often undiagnosed cause
of pain.8 Many authors have suggested that differentiation between the types of fracture is important with
respect to management and advocate the use of bone
scintigraphy, MRI and CT.4,9,10 We did not find these
techniques to be particularly useful for the identification
THE JOURNAL OF BONE AND JOINT SURGERY
PERCUTANEOUS SCREW FIXATION FOR FRACTURES OF THE SESAMOID BONES OF THE HALLUX
of the type of fracture. It is likely that our series includes
patients with acute fractures, nonunions and stress fractures. We have treated all by percutaneous fixation and
have achieved excellent results. We therefore question
the importance of diagnosing the aetiology of the fracture.
The percutaneous technique using the Barouk screw is
relatively simple and free from complications. We have
demonstrated an early resolution of symptoms, a rapid
return to sport and a statistically significant functional
improvement using the AOFAS.
We agree with other authors that the sesamoids are critical to the preservation of the function of the great toe, particularly in high-performance athletes.11 The procedure
described restores the integrity of the sesamoid in a relatively atraumatic fashion, without compromising function.
We recommend this technique for active individuals with
fractures in whom the line of the fracture is orientated predominantly transversely without comminution.
Seven of our nine patients were high-performance athletes. The management of fractures of the sesamoids in such
patients is acknowledged to be difficult and we were therefore encouraged by our results using this new percutaneous
technique.
VOL. 84-B, No. 8, NOVEMBER 2002
1141
No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article.
References
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