Targeted Muscle Reinnervation: Surgical Protocol for a Randomized Controlled Trial in Postamputation Pain

Published: March 8th, 2024

DOI:

¹Center for Bionics and Pain Research, ²Center for Advanced Reconstruction of Extremities, Sahlgrenska University Hospital, ³Department of Electrical Engineering, Chalmers University of Technology, ⁴Bionics Institute, ⁵IV Clinica Ortoplastica, IRCCS Istituto Ortopedico Rizzoli, ⁶Department of Hand Surgery, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University Hospital, ⁷Department of Orthopedic, Hand Unit, Worker Hospital, ⁸College of Medicine and Veterinary Medicine, The Queen's Medical Research Institute, The University of Edinburgh, ⁹Canniesburn Plastic Surgery Unit, Glasgow Royal Infirmary, ¹⁰College of Medicine, Veterinary & Life Sciences, The University of Glasgow, ¹¹Division of Plastic Surgery, Department of Surgery, Faculty of Medicine and Dentistry, University of Alberta, ¹²Plastics and Reconstructive Surgery, Dandenong Hospital, Monash Health, ¹³Division of Plastic and Reconstructive Surgery, Massachusetts General Hospital &, Harvard Medical School, ¹⁴Section of Plastic Surgery, Department of Surgery, Michigan Medicine, ¹⁵Department of Surgery, Uniformed Services University of the Health Sciences and Walter Reed National Military Medical Center, ¹⁶Department of Plastic and Reconstructive Surgery, Ohio State University, ¹⁷Clinical Laboratory for Bionic Extremity Reconstruction, Department of Plastic, Reconstructive and Aesthetic Surgery, Medical University Vienna, ¹⁸Division of Plastic Surgery, Department of Surgery, Northwestern Feinberg School of Medicine, ¹⁹Medical Bionics Department, University of Melbourne, ²⁰Prometei Pain Rehabilitation Center

Over the past decade, the field of prosthetics has witnessed significant progress, particularly in the development of surgical techniques to enhance the functionality of prosthetic limbs. Notably, novel surgical interventions have had an additional positive outcome, as individuals with amputations have reported neuropathic pain relief after undergoing such procedures. Subsequently, surgical techniques have gained increased prominence in the treatment of postamputation pain, including one such surgical advancement - targeted muscle reinnervation (TMR). TMR involves a surgical approach that reroutes severed nerves as a type of nerve transfer to "target" motor nerves and their accompanying motor end plates within nearby muscles. This technique originally aimed to create new myoelectric sites for amplified electromyography (EMG) signals to enhance prosthetic intuitive control. Subsequent work showed that TMR also could prevent the formation of painful neuromas as well as reduce postamputation neuropathic pain (e.g., Residual and Phantom Limb Pain). Indeed, multiple studies have demonstrated TMR's effectiveness in mitigating postamputation pain as well as improving prosthetic functional outcomes. However, technical variations in the procedure have been identified as it is adopted by clinics worldwide. The purpose of this article is to provide a detailed step-by-step description of the TMR procedure, serving as the foundation for an international, randomized controlled trial (ClinicalTrials.gov, NCT05009394), including nine clinics in seven countries. In this trial, TMR and two other surgical techniques for managing postamputation pain will be evaluated.