Intraneural Topography and Branching Patterns of the Common Peroneal Nerve: Studying the Feasibility of Distal Nerve Transfers

Abstract

Background: Common peroneal nerve (CPN) disruption is the most common lower extremity nerve injury and results in gait disturbances and sensory paresthesias. The goal of this study is to describe branching patterns and the intraneural topography of the CPN to facilitate operative planning in CPN reconstruction. Methods: The CPN and its distal motor and sensory branches were dissected in 6 lower leg cadavers. Branching patterns and distances were recorded with the fibular head as the landmark. Histological review of the nerve cross sections helped characterize the intraneural topography within the fibular tunnel. Results: The CPN distal branching patterns were highly variable. The tibialis anterior motor branch was found on average 9.6 cm distal to the fibular head. Despite the variable branching patterns, the fascicular topography of the CPN within the fibular tunnel was consistent. Proximal to the tunnel, the nerve has 3 major fascicles, which include the superficial peroneal motor, common sensory, and deep peroneal motor (DPN) fascicles from lateral to medial. Within the tunnel, the topography consolidates into the superficial peroneal motor and DPN major divisions—motor axons anteriorly and sensory axons posteriorly. Conclusions: The data presented provide clinically relevant information for the peripheral nerve surgeon where fascicular reconstruction of the nerve and neurolysis should focus on the anterior half of the nerve to restore ankle dorsiflexion. The nerve proximally is divided into 3 major fascicles compared with 2 distally. Surgeons may consider distal nerve transfers from the tibial nerve motor branches to the DPN or tibialis anterior motor branch.