Anatomic Feasibility of Intercostal-to-Femoral and Ulnar-to-Sciatic Nerve Transfers for Lower Extremity Neurotization After Traumatic Spinal Cord Injury

BACKGROUND: Traumatic spinal cord injury (SCI) is associated with functional morbidity and limited options for restoring lower extremity motor function. This study explores the technical feasibility of intercostal-to-femoral and ulnar-to-sciatic nerve transfers as a potential approach to reinnervate the lower limb following SCI. METHODS: A cadaveric anatomical feasibility study was performed using a fresh-frozen adult human specimen to evaluate two novel nerve transfer strategies: posterior intercostal-to-femoral nerve transfer and long-segment ulnar-to-sciatic nerve transfer. Dissections assessed the ability to achieve direct, tension-free coaptation without interposition nerve grafts. RESULTS: Intercostal nerves T8–T10 were successfully harvested, mobilized, and tunneled to the proximal femoral nerve, demonstrating >2 cm overlap sufficient for tension-free coaptation. Similarly, long-segment ulnar nerve harvest from the hypothenar region to the axilla enabled subcutaneous tunneling to the gluteal region and direct end-to-end coaptation with the sciatic nerve without the need for grafting. Both nerve transfer techniques avoided excessive tension at the coaptation sites. CONCLUSIONS: These findings establish the anatomic feasibility of intercostal-to-femoral and ulnar-to-sciatic nerve transfers and provide a practical anatomic foundation for future translational studies aimed at restoring lower extremity function in patients with SCI.