Superficial Peroneal Nerve Motor Branch Transfer to the Deep Peroneal Nerve: Cadaveric Study and Case Report.

Background: Foot drop carries substantial morbidity and is often due to deep peroneal (DPN) or common peroneal nerve (CPN) injury. Treatment options are limited. This study explored a new surgical approach by transferring a superficial peroneal nerve (SPN) branch to DPN. Cadaveric analysis, manual histomorphometry, and a case report are presented. Methods: Twenty-one limbs were analyzed. A reproducible surgical approach was used to identify CPN and trace it to the bifurcation into SPN and DPN, and then to the insertions into the peroneus longus (PL) and tibialis anterior (TA) muscles, respectively. Measurements were made from the superior most aspect of the fibular head to the bifurcation of the CPN, the insertion of the first and second SPN motor branches to the PL, and to the insertion of the DPN into the TA. The first SPN motor branch to the PL and DPN into the TA nerves were harvested, and histomorphological measurements of axonal densities were obtained. Results: Histomorphological analysis showed similar axonal densities between the transferred and target nerves, indicating a comparable potential for effective reinnervation. The mean distances from fibular head to various nerve branches were recorded to ensure tension-free transfer. No significant differences were found between nerve groups regarding axon density, total fascicle area, or total axon counts. Conclusions: This study supported feasibility of this nerve transfer technique, with initial results suggesting it represents a viable treatment option for foot drop secondary to DPN injury. Further research is needed to confirm these findings.