Hand Transplantation.

U pper extremity loss represents a life-changing, often devastating event, affecting nearly every activity of daily living and subsequently leaving a patient with substantial disability. The potential immediate dependency and despair resulting from the loss of one or both hands cannot be overstated. Promising technological advances in upper extremity prostheses include improved neural-control interfaces, multiple-degrees-of-freedom terminal devices, and prototype haptic feedback mechanisms. However, the available literature still demonstrates high prosthesis rejection rates for upper extremity amputees, suggesting that prostheses continue to inadequately replicate the complex, prehensile functions of the native hand and arm. The most commonly cited reasons for upper extremity prosthesis rejection remain limited usefulness, weight, and residual limb discomfort. Pioneers of hand transplantation recognized that prosthetic devices probably would never completely satisfy the upper extremity amputee for these very reasons. Even if the prehensile function and dexterity of the human hand could be restored, these would do little to restore patient body image or hand sensibility, both traits coveted by amputees. Rather, they postulated that these could only be replaced with “like” human tissue. The field of vascularized composite allotransplantation has grown from this basic desire to fully restore both the functional and emotional aspects of the human hand, building on the foundations developed by solid organ transplantation, hand surgery, and reconstructive microsurgery. The concept of using composite tissue allograft was first suggested in 1960 by Peacock, when he utilized cadaveric flexor tendons along with their synovial sheaths in order to reconstruct end-stage tendon incarcerations that otherwise would have