Background: Upper limb trauma may present as both soft tissue and muscle defects necessitating a free skin flap to effect a repair. The limb's core (basic) functionality can be returned with a secondary tendon transfer or a functioning muscle transfer. A functioning muscle flap can provide for soft tissue repair and functional restoration in a single procedure, but the success of such procedures requires further clarification.
Material: From 1997 to 2006, nine patients underwent free functioning muscle transfer performed for upper extremity composite structure and functional defects, including four flexor digitorum profundus muscle and three extensor digitorum comminis muscle defects. Seven thumb tendon defects were managed with simultaneous tendon and free functioning muscle transfer. In addition, two opponensplasties and one thumb basal joint arthrodesis were performed for thumb function revision.
Result: In all nine patients, procedures were completed without complications, the flaps surviving, enabling the patients to achieve opposable hand function. The muscle strength accomplished M4.2 (M3-5). The grip power was 41.7, and pinch power 55.3%, when compared with the other hand.
Conclusion: Primary functioning muscle transfer can provide a one-stage composite functional restoration in an open wound. The thumb can be reconstructed with tendon transfer followed by opponensplasty to achieve a satisfactory range of opposable function.