Treatment of Phantom and Residual Limb Pain in Amputees With Targeted Muscle Reinnervation.

Background: Many amputees are left with chronic localized pain, centralized pain, and phantom limb pain or sensation, often resulting from neuromas in the residual limb. Historically, there is no reliably effective intervention for pain associated with neuroma-related residual or phantom limb pain. Targeted muscle reinnervation (TMR) is a surgical procedure first described in 2002 that involves the transfer of residual nerves from amputated limbs to new muscle targets. TMR has been shown to significantly reduce neuroma pain and facilitate the use of prostheses.

Methods: A prospective study was conducted of 61 patients who underwent TMR for neuroma treatment or prevention between 2017 and 2022. Primary outcomes included overall, phantom, and residual limb pain recorded using the Visual Analog Scale (VAS), as well as Patient-Reported Outcomes Measurement Information System (PROMIS) forms for Pain Intensity, Quality, Interference, and Behavior. Retrospective data was collected for a propensity-matched cohort of non-TMR amputees to compare pain outcomes.

Results: TMR was performed for 25 upper extremity and 35 lower extremity amputations, and 5 patients underwent TMR on multiple limbs. Significant reductions were observed in overall limb pain (-3.2 points), phantom limb pain (-2.6 points), and residual limb pain (-3.0 points) for the TMR cohort. Mean PROMIS scores for TMR patients were 49.7 for Pain Intensity, 54.0 for Pain Quality, 55.3 for Pain Interference, and 56.1 for Pain Behavior. At the 8.4-month follow-up, 43.8% of TMR patients (vs 84% of controls) remained on neuromodulators, opioids, or both, for pain control.

Conclusions: TMR improved phantom and residual limb pain in amputees, as evidenced by clinically and statistically significant reductions in pain with reduced need for long-term opioids and/or neuromodulators. These findings support the current understanding of TMR but underscore the need for continued investigation to comprehensively assess the potential of this promising technique in improving the functional outcomes and quality of life in the amputee population.