Targeted Muscle Reinnervation for Limb Amputation to Avoid Neuroma and Phantom Limb Pain in Patients Treated at a Pediatric Hospital

Abstract

Background: Amputees frequently experience chronic neuroma-related residual limb and phantom limb pain (PLP). Targeted muscle reinnervation (TMR) transfers transected nerves to nearby motor nerves to promote healing and prevent neuroma formation and PLP. The purpose of this study was to report outcomes of TMR in a series of children and young adults treated at a pediatric hospital. Methods: Patients undergoing major limb amputation with TMR were included with minimum one year follow-up and completed questionnaires. Primary clinical outcomes included incidence of symptomatic neuromas, PLP, residual limb pain, narcotic use, and neuromodulator use. A follow-up phone survey was conducted assessing five pediatric Patient Reported Outcomes Measurement Information System (PROMIS) metrics adapted to assess residual limb and PLP. Results: Nine patients (seven male and two female patients, avg. age = 16.83 ± 7.16 years) were eligible. Average time between surgery and phone follow-up was 21.3 ± 9.8 months. Average PROMIS Pediatric t-scores for measures of pain behavior, interference, quality—affective, and quality—sensory for both PLP and residual limb pain were nearly 1 standard deviation lower than the United States general pediatric population. One patient developed a symptomatic neuroma 1 year after surgery. Conclusions: Compared with an adult patient sample reported by Valerio et al, our TMR patients at Nationwide Children’s Hospital (NCH) showed similar PLP PROMIS t-scores in pain behavior (50.1 versus 43.9) and pain interference (40.7 versus 45.6). Both pediatric and adult populations had similar residual limb pain including PROMIS pain behavior (36.7 adult versus 38.6 pediatric) and pain interference (40.7 adult versus 42.7 pediatric). TMR at the time of amputation is feasible, safe, and should be considered in the pediatric population.