Targeted Muscle Reinnervation: A Brief History of a Promising Procedure for Effective Management of Amputation Pain

Abstract

Each year, 27.5% of the 150 000 people in the United States who require lower extremity amputation experience significant postoperative complications, including pain, infection, and need for reoperation. Postamputation pain, including RLP and PLP, is debilitating. While the causes of such pain remain unknown, neuroma formation following sensory nerve transection is believed to be a major contributor. Various techniques exist for management of a symptomatic neuroma, but few data exist on which technique is superior. Furthermore, there are few data on primary prevention of neuroma formation following injury or intentional transection. The TMR technique shows promise for both management of PLP and RLP and prevention of neuroma formation. Following amputation, transected sensory nerves are coapted to nearby motor nerve supplying remaining extremity musculature. Not only does this procedure generate increased myoelectric signals for improved prosthesis control, TMR appears to neurophysiologically alter sensory nerves, preventing formation of painful sensory neuromas. The sole RCT to date evaluating the efficacy of TMR showed statistically significant reduction in PLP. TMR is not limited to use in the setting of major limb amputation. It has also been used in the setting of post-mastectomy pain, abdominal wall neuromas, digital amputations, and headache surgeries. This article reviews the origin of TMR and provides a brief description of histologic changes following the procedure, as well as current data regarding the efficacy of TMR with regard to postoperative pain relief. It also seeks to provide a concise, comprehensive resource for providers to facilitate better discussions with patients about treatment options.