Targeted Muscle Reinnervation in Amputees: A Review of Current Techniques

Targeted muscle reinnervation (TMR) is a surgical technique that was initially developed for amputees to improve prosthetic control. TMR reroutes the ends of amputated nerves into more proximal motor nerves supplying residual redundant muscle groups. In doing so, it restores motor signals from the brain that would otherwise be lost by the amputation and allows the redundant muscle to communicate this lost function to a prosthetic device. Although initially developed for functional purposes, TMR has subsequently been shown to treat neuropathic and phantom limb pain. As such, indications for its use have significantly expanded. TMR is now widely performed for both upper and lower extremity amputees, at various amputee levels. While technical roadmaps have been published for many amputation levels, the goal of this paper is to update and summarize all these techniques in one place.