Shoulder Disarticulation Externally Powered Prosthetic Fitting Following Targeted Muscle Reinnervation for Improved Myoelectric Control

In Brief Functional prosthetic restoration is challenging for individuals with high-level upper extremity amputations. It is of greater consequence when the individual has sustained bilateral limb loss. It is possible to denervate expendable regions of muscle in or near an amputated limb and transfer the residual peripheral nerves to this muscle. The surface EMG signals from the reinnervated muscle can then be used as additional control signals for an externally powered prosthesis. This technique, called “targeted reinnervation,” allows the simultaneous control of multiple degrees of freedom in a prosthesis. Control of the prosthesis is also easier and more natural because the myoelectric signals are physiologically correlated to the movements of the lost arm and could greatly improve the function of myoelectric prostheses. The authors describe the first application of targeted reinnervation to a man with bilateral shoulder disarticulation amputations, with a focus on the prosthetic fitting and its challenges. The surgical procedure and preliminary outcomes are presented. The restoration of function in shoulder disarticulation patients is challenging. In an attempt to improve functional control of myoelectric prostheses, an effort has been made to study the possibility of transferring the residual nerves to spare muscles in or near the residual limb. These nerves are used to reinnervate targeted muscles, and then surface myoelectric signals from the reinnervated muscle can be used as additional control signals for an externally powered prosthesis. Because the nerves would be controlling functions in the prosthesis that they controlled in the natural arm, operation of the device is easier and more natural. The authors describe the first application of this technique, called “targeted reinnervation,” to a man with bilateral shoulder disarticulation amputations, with a focus on the prosthetic fitting and its challenges.