Targeted muscle reinnervation following external hemipelvectomy or hip disarticulation: An anatomic description of technique and clinical case correlates

Background: Targeted muscle reinnervation (TMR) has been shown to decrease or prevent neuropathic pain, including phantom and residual limb pain, after extremity amputation. Currently, a paucity of data and lack of anatomical description exists regarding TMR in the setting of hemipelvectomy and/or hip disarticulations. We elaborate on the technique of TMR, illustrated through cadaveric and clinical correlates. Methods: Cadaveric dissections of multiple transpelvic exposures were performed. The major mixed motor and sensory nerve branches were identified, dissected, and tagged. Amputated peripheral nerves were transferred to identified, labeled target motor nerves via direct end-to-end nerve coaptations per traditional TMR technique. A retrospective review was completed by our multi-institutional teams to include examples of clinical correlates for TMR performed in the setting of hemipelvectomies and hip disarticulations. Results: A total of 12 TMR hemipelvectomy/hip disarticulation cases were performed over a 2 to 3-year period (2018-2020). Of these 12 cases, 9 were oncologic in nature, 2 were secondary to traumatic injury, and 1 was a failed limb salvage in the setting of chronic refractory osteomyelitis of the femoral shaft. Conclusions: This manuscript outlines the technical considerations for TMR in the setting of hemipelvectomy and hip disarticulation with supporting clinical case correlates.