Clinical Importance of Variations in the Surgical Anatomy of the Superficial Peroneal Nerve in the Mid-Third of the Lateral Leg

The superficial peroneal nerve (SPN) provides fundamental motor and sensory innervation to the leg and foot. A variety of surgical procedures are performed in the vicinity of this nerve, requiring that the surgeon be familiar with its specific anatomic landmarks. This is particularly important when neurolysis or excision of the SPN is performed via small/targeted incisions, usually 12–15 cm above the lateral ankle. Observations of the SPN anatomical variations at this level led to a literature search that failed to identify a report describing the author's findings. One hundred eleven legs were dissected to define the anatomical position and relationships of the SPN, and it was found that the nerve had four distinct patterns in the lateral mid-third of the leg. In 78 specimens (70.3%), the nerve coursed within the lateral compartment of the leg, while in 14 (12.6%), the nerve split and contained branches in both the lateral and anterior compartments. Finally, in 10 legs (9%), the nerve was found within the intermuscular septum, and in nine of the specimens (8.1%), the SPN traveled only within the anterior compartment. Examples of specific procedures which are performed on the lateral leg, such as fasciotomies, nerve decompressions, and fracture reductions, were discussed. Results which reveal the four variations in anatomical position of the SPN will certainly aid surgeons in locating the nerve in the lateral aspect of the leg and will help to decrease the risk of iatrogenic injury, while increasing the rates of surgical success when neurolysis or excisions are performed.