Efficacy of targeted muscle reinnervation for treating and preventing postamputation pain - a systematic review

Abstract

Aim: Targeted muscle reinnervation (TMR) is a procedure pioneered to improve control of myoelectric prostheses and was fortuitously found to improve postamputation pain by transferring residual nerve ends from an amputated limb to reinnervate motor nerve units in denervated muscles. This study sought to perform a systematic review of the literature regarding the postamputation pain-related outcomes following TMR. Methods: PubMed database was queried using the key term “targeted muscle reinnervation”. Articles were chosen based on the following criteria: (1) clinical studies on TMR; (2) greater than one subject; (3) studies were case-controls, comparative cohort analyses, controlled trials, or randomized controlled trials; and (4) studies included one or more outcomes of interest: prosthetic use and functionality, improvement or persistence of pain, indications, complications, donor nerves, and technical aspects of TMR. Results: Overall, 9 studies including 101 upper extremity and 252 lower extremity nerve transfers were analyzed, with nerve transfer type, amputation location, and specific neurotizations reported. Four studies assessed the efficacy of TMR in addressing phantom limb pain (PLP) and residual limb pain (RLP), with 3 out of 4 studies reporting significant improvements in PROMIS (Patient Reported Outcome Measurement Information System) scores in TMR subjects compared to controls. Five additional studies did not analyze PROMIS scores but reported subjective improvements in pain outcomes. Conclusion: Included studies demonstrated TMR had lower maximal pain and pain intensity, behavior and interference compared to the standard of care. Secondary TMR used to treat patients with established painful neuromas also reported improvement in pain compared to baseline.