Updates in Targeted Sensory Reinnervation for Upper Limb Amputation

Abstract

Advanced robotic devices capable of simulating the dexterous ability of the upper limb with an array of internal sensors have raised the enticing prospect of replacing the lost intricate functions of the arm following upper limb amputation. However, a large gap still exists in the application of this technology to the human user. In particular, the ability to provide physiologically relevant sensory feedback—to have the amputee feel the prosthetic hand as their own—has not yet been achieved. Although a number of different approaches are being investigated, targeted sensory reinnervation, a refinement of the original targeted muscle reinnervation procedure, is the most recent and promising development in the effort to create a functional human–machine interface with a closed loop sensory feedback system. This technique aims to re-establish hand sensation on the skin so that it can be readily accessed non-invasively during functional tasks. Recent efforts are being directed towards distributing hand maps widely on the stump without interference of sensations from the native area. In this article, we will review the surgical approaches that have been used for sensory reinnervation in upper arm amputation and compare the resultant outcomes and potential functional utility of the techniques.