Targeted Muscle Reinnervation for Partial Hand Amputation

BACKGROUND: Targeted muscle reinnervation for the treatment of symptomatic neuromas after upper limb amputation has been described for shoulder disarticulation and for transhumeral and transradial amputations. Early clinical outcomes are promising and demonstrate a statistically significant reduction in phantom limb pain and a decrease in residual limb pain. METHODS: We performed a cadaver dissection of the motor branches arising from the median and ulnar nerves to assess whether this technique could be applied to symptomatic neuromas after partial hand and finger amputations. RESULTS: After identification of all branches under 4.5x loupe magnification, we performed simulated transfers of digital nerves to lumbrical motor branches, common digital nerves to lumbrical motor branches or the recurrent motor branch, and the common sensory portion of the ulnar nerve to a hypothenar motor branch. CONCLUSIONS: The proximity of all sensory nerves to motor branches and the numerous redundant motor nerve targets available support our hypothesis that targeted muscle reinnervation is possible after partial hand or finger amputation. Further studies will be required to refine clinical indications and evaluate outcomes.