Brachioradialis tendon transfer and palmaris longus tendon graft for thumb avulsion: A case report and review of literature.

Background: Thumb replantation following complete traumatic avulsion requires complex techniques to restore function, especially in cases of avulsion at the level of the metacarpophalangeal joint (MCP I) and avulsion of the flexor pollicis longus (FPL) at the musculotendinous junction. Possible treatments include direct tendon suture or tendon transfer, most commonly from the ring finger. To optimize function and avoid donor finger complications, we performed thumb replantation with flexion restoration using brachioradialis (BR) tendon transfer with palmaris longus (PL) tendon graft.

Case summary: A 20-year-old left-handed male was admitted for a complete traumatic left thumb amputation following an accident while sliding from the top of a handrail. The patient presented with skin and bone avulsion at the MCP I, avulsion of the FPL tendon at the musculotendinous junction (zone 5), avulsion of the extensor pollicis longus tendon (zone T3), and avulsion of the thumb's collateral arteries and nerves. The patient was treated with two stage thumb repair. The first intervention consisted of thumb replantation with MCP I arthrodesis, resection of avulsed FPL tendon and implantation of a silicone tendon prosthesis. The second intervention consisted of PL tendon graft and BR tendon transfer. Follow-up at 10 months showed good outcomes with active interphalangeal flexion of 70°, grip strength of 45 kg, key pinch strength of 15 kg and two-point discrimination threshold of 4 mm.

Conclusion: Flexion restoration after complete thumb amputation with FPL avulsion at the musculotendinous junction can be achieved using BR tendon transfer with PL tendon graft.