“Targeted Muscle Reinnervation in the Lower Leg: An Anatomic Study.”

Introduction: Targeted muscle reinnervation (TMR) re-routes the ends of cut nerves to re-innervate small motor nerves of nearby muscles, with the goal of reducing neuroma pain and/or improving prosthesis function. Anatomical roadmaps for TMR have been established in the upper extremity and thigh, but not for the lower leg. Methods: The major branch points (MBPs) of motor nerves and the motor entry points (MEPs) to muscles of the leg were dissected in five cadaver specimens. Leg length was defined as distance from lateral femoral condyle to lateral malleolus. The distances from the lateral femoral condyle to MBPs and MEPs were recorded as a percentage of leg length to identify targets for TMR. Results: The tibialis anterior and extensor digitorum longus were both acceptable targets in the anterior compartment, with an average 4.4 MEPs within 10-80% and 3 MEPs within 20-80% leg length, respectively. The peroneus longus was the best target in the lateral compartment, with an average 5.8 MEPs within 20-70% leg length. The gastrocnemius and soleus were both acceptable targets in the superficial posterior compartment, with an average 4.4 MEPs within 0-40% and 6.2 MEPs within 20-80% leg length, respectively for each muscle. The flexor digitorum longus was the best target in the deep posterior compartment, with an average 6 MEPs within 30-90% leg length. Conclusions: TMR is technically feasible in the lower leg. This cadaveric study provides a roadmap for incision placement and identification of motor nerve targets. Financial Disclosure Statement: Dr. Ko is a speaker for Checkpoint Surgical, Cleveland OH. Dr. Dumanian is a speaker for Axogen, Inc. Alachua, FL. No funding was received for this article. Corresponding author: Gregory Dumanian, MD, ivision of Plastic Surgery, Northwestern Memorial Hospital, 675 N. St. Clair St, Suite19-250, Chicago, IL 60611 USA. email: gdumania@nm.org ©2018American Society of Plastic Surgeons