Replantation of the Thumb

The thumb has a significant impact on the overall function of the hand, and its absence can result in major impairment and disability. Functional impairment following the loss of the thumb will reliably degrade the overall function of the hand with a loss of 50 % of grasp, 30 % of pinch, and 20 % of hook strengths. Given these factors, the thumb has been assigned a relative value of impairment of 40 %, further emphasizing the dictum that the thumb should be replanted in all situations possible. The mechanism of injury is a significant predictor of ultimate function, both in regard to strength and range of motion. It should be noted that severe avulsion and crush injuries affect the functional outcome, as well as the possibility of performing the replantation. Replantation should proceed in a stepwise manner, following a thorough debridement and irrigation of the injury site and amputated part. Midlateral incisions on the amputated part and proximal stump allow for exploration of the volar structures, including the flexor sheath and neurovascular bundles. Ultimately, functional success is based upon the ability of the surgeon to reconstruct the bony and soft tissues, as well as the patient’s motivation and compliance with perioperative management and rehabilitative hand therapy.