Upper Extremity Tendon Transfers: A Brief Review of History, Common Applications, and Technical Tips.

Background  Tendon transfer in the upper extremity represents a powerful tool in the armamentarium of a reconstructive surgeon in the setting of irreparable nerve injury or the anatomic loss of key portions of the muscle-tendon unit. The concept uses the redundancy/expendability of tendons by utilizing a nonessential tendon to restore the function of a lost or nonfunctional muscle-tendon unit of the upper extremity. This article does not aim to perform a comprehensive review of tendon transfers. Instead it is meant to familiarize the reader with salient historical features, common applications in the upper limb, and provide the reader with some technical tips, which may facilitate a successful tendon transfer. Learning Objectives  (1) Familiarize the reader with some aspects of tendon transfer history. (2) Identify principles of tendon transfers. (3) Identify important preoperative considerations. (4) Understand the physiology of the muscle-tendon unit and the Blix curve. (5) Identify strategies for setting tension during a tendon transfer and rehabilitation strategies. Design  This study was designed to review the relevant current literature and provide an expert opinion. Conclusions  Tendon transfers have evolved from polio to tetraplegia to war and represent an extremely powerful technique to correct neurologic and musculotendinous deficits in a variety of patients affected by trauma, peripheral nerve palsies, cerebral palsy, stroke, and inflammatory arthritis. In the contemporary setting, these very same principles have also been very successfully applied to vascularized composite allotransplantation in the upper limb.