Free function muscle transfers for upper extremity reconstruction: a review of indications, techniques, and outcomes

Free functional muscle transfer (FFMT) replaces destroyed, denervated, or resected skeletal muscle units in the upper extremity with functioning skeletal muscle from other locations in the body. Common indications for FFMT include brachial plexus injuries, ischemic contracture, tumor resection, and extensive direct muscle trauma. Recent studies have focused on improving patient outcomes through refinements in muscle flap harvest and inset, donor nerve selection, and postoperative management. In this review, we assess and summarize the current literature on FFMT, with emphasis on etiopathogenesis, diagnosis, treatment, postoperative management, and clinical outcomes.