Bilateral thumb metacarpophalangeal joint fusions for severe hyperextension deformities in conjunction with carpometacarpal joint reconstructions.

BACKGROUND: Hyperextension of the first metacarpophalangeal (MCP) joint and adduction of the first web space of the hand are features of advanced stages of carpometacarpal (CMC) joint arthrosis. Restoration of mechanical efficiency in such patients requires stabilization of both the CMC and MCP joints. This study describes a patient with bilateral secondary hyperextension of the MCP joint greater than 50° who displayed good functional outcome following staged bilateral MCP joint arthrodesis with simultaneous CMC joint reconstruction. CASE REPORT: Excision of trapezium, formation of a Weilby sling utilising flexor carpi radialis, and insertion of a Swanson's prosthesis forms the basis of CMC joint reconstruction. Fusion of the MCP joint involved placement of longitudinal K-wires and tension band wiring. The patient underwent an initial right-sided procedure in 2008 and subsequently elected for the same procedure on the contralateral side 26 months later. Good functional improvement was achieved with a pre and postoperative DASH score of 49 and 8 respectively. Follow-up and radiological imaging at 34 months from her initial surgery confirmed good positions of the prostheses and solid MCP joint fusions. The patient developed postoperative interphalangeal joint pain, which responded to steroid injection. DISCUSSION: There is currently limited evidence available addressing the management of severe hyperextension deformity greater than 50° of the MCP joint in the presence of CMC joint arthrosis. Staged bilateral fusion of the MCP joint and simultaneous CMC joint reconstruction in this case illustrates good, reproducible functional results and patient satisfaction with reduced postoperative return to function.

Collateral ligament injuries of the metacarpophalangeal joint of the thumb: a treatment algorithm.

The management of injury to the ulnar and radial collateral ligaments at the metacarpophalangeal joint of the thumb is complex. Treatment is dependent upon a number of factors with a wide variety of options for each ligament. Inadequate treatment has the potential to lead to a poor functional outcome. We present the relevant clinical anatomy, mechanism of injury, methods of treatment available and suggest a single treatment algorithm for use in the management of these injuries.

Tenodermodesis for established mallet finger deformity.

Sixteen patients with established mallet finger deformity as a result of extensor tendon injury were treated by tenodermodesis and fixation of the distal interphalangeal joint with a Kirshner wire. The patients were followed for a mean of 36 months (range 10-60). The results were excellent in eight patients, good in six, and fair in two. The mean extension lag was decreased from 50 degrees (range 30-70) to 9 degrees (range 0-30), but not at the expense of impaired flexion capacity. All patients were pleased with their resultant function and cosmesis. No complications were encountered. We recommend the operation for passively correctable deformities with suitable joints; it is easy to do and yields consistently successful results.

Non-operative treatment of displaced avulsion fractures of the ulnar base of the proximal phalanx of the thumb.

Treatment of displaced or rotated avulsion fractures of the ulnar base of the proximal phalanx of the thumb remains controversial. There is limited information on the outcome of management of these injuries by non-surgical means. We undertook a retrospective follow-up study of the non-operative treatment of these fractures. The study included 28 thumbs that were stable to lateral stress testing at the time of initial investigation. The patients were treated by immobilisation of the thumb in a spica cast. The mean follow-up interval was 2.5 years (range 1-4). None of the patients changed their permanent employment or was unable to participate in their usual sporting activities. Twenty-six patients (93%) reported no pain on movement of the thumb. At follow-up, grip and pinch strengths did not differ significantly on the injured and non-injured sides. No thumbs showed instability on stress testing. The fractures had a 40% rate of bony union and 60% rate of fibrous non-union. All the patients were satisfied with their outcome. None of the patients was operated on after treatment. Non-operative treatment is recommended in cases of displaced or rotated avulsion fractures provided that there is no lateral instability of the metacarpophalangeal joint. Patients with unstable thumbs should always be treated surgically.