Targeted Muscle Reinnervation to Reduce Postoperative Pain in Patients Undergoing Hindquarter Resections

Background/Aim: Pre-emptive targeted muscle reinnervation (TMR) at the time of amputation results in less phantom limb pain (PLP) compared with untreated amputee controls. There is limited literature describing the technique in patients undergoing hindquarter amputation despite up to 90% of these patients reporting PLP and 50% presenting with painful neuroma. The purpose of the current study was to describe the motor nerves accessible through a primary hind-quarter amputation to be used for TMR and review pain outcomes in clinical case correlates of patients with TMR. Patients and Methods: Six limbs were obtained from three fresh adult cadavers and proximal sensory and motor nerves were dissected. A review of patients undergoing hindquarter amputation with TMR was conducted. Results: Transfers for the sciatic, femoral, and obturator nerves were identified in cadavers. In reviews of patients, they were taking narcotic and neuro-leptic pain medication for a mean of 23 days and 168 days. At most recent follow-up, no patient reported debilitating phantom pain nor pain associated with neuromas. Conclusion: Given the positive preliminary results in our study group as well as the accessible neuroanatomy, pre-emptive TMR should be considered at the time of surgery to limit PLP and dependence on pain medications. Hindquarter amputations (external hemipelvectomy and hip disarticulation), are rare procedures that can impart substantial functional limitations and poor pain outcomes, limiting post-operative rehabilitation and overall quality of life (1, 2). Most patients with hindquarter amputation report phantom limb sensation as well as phantom limb pain (PLP) post-operatively (3), with up to 90% of patients with lower limb amputations reporting phantom limb pain and 50% presenting with painful neuroma (4, 5).