Anterior Branch of the Obturator Nerve A Novel Motor Autograft for Complex Peripheral Nerve Reconstruction

Background: Autografting is the optimal reconstruction for many nerve gaps, because the retained nerve architecture serves as a regenerative scaffold. Experimental evidence suggests that motor regeneration is favored with the use of a motor nerve graft as compared with sensory nerve autografts, but clinical descriptions are lacking in the literature. As a novel solution, we report our use of the anterior branch of the obturator nerve as a large segment motor nerve graft with minimal functional morbidity. Case: A 17-year-old boy reported progressive weakness and atrophy of the right thigh due to a multifascicular femoral nerve tumor. Motor branch defects of 7 and 4 cm were reconstructed using autografts from the motor nerve to the gracilis (MNG). The patient noted gradual clinical improvement in quadriceps strength, and repeat electromyography at 8- and 13-month follow-ups demonstrated improving motor unit action potentials and quadriceps muscle recruitment. Discussion: The MNG is readily available, with an average total donor length of 11.4 cm. The use of motor nerve grafts is supported by experimental models demonstrating superior nerve regeneration. The MNG is a compelling choice for clinical use because donor-site morbidity is minimized by redundancy of the thigh adductors and a favorable incision location. Conclusion: This is the first published description of successful use of the anterior branch of the obturator nerve as a robust donor motor nerve graft. Clinical use of this graft may maximize functional outcomes and minimizes donor-site morbidity compared with traditional sensory nerve grafts.