Common Peroneal Nerve, Posterior View

Description

Arising as the lateral terminal branch of the sciatic nerve, the common fibular (peroneal) nerve is followed in posterior aspect as it descends through the popliteal fossa toward the posterolateral knee. Proximally it lies lateral to the tibial nerve, then tracks along the medial border of the biceps femoris tendon before crossing superficially over the lateral head of gastrocnemius. Distally, it winds around the neck of the fibula, just inferior to the fibular head, where its position becomes distinctly subcutaneous against the lateral proximal leg. Adjacent osseous landmarks include the distal femur, patella, tibia, and fibula, with accompanying popliteal-region vessels rendered to orient the neurovascular corridor. Posterior visualization matters because this is the segment most often injured in knee trauma and entrapment, and it is also the segment surgeons must respect when working posterolaterally. Compression at the fibular neck from tight casts, habitual leg crossing, or rapid weight loss can produce common fibular neuropathy with foot drop from weakness of ankle dorsiflexion and eversion, plus sensory loss over the dorsum of the foot and lateral shin. This course also explains why fibular head fractures and posterolateral corner injuries can present with disproportionate neurologic deficits. A small nerve, a big clinical problem. Use it to teach lower-limb neuroanatomy in gross anatomy and MSK courses, to illustrate popliteal fossa relationships in a surgical atlas, or to support clinical education on evaluating peroneal nerve palsy and planning safe incisions around the fibular head and lateral knee. Anatomical accuracy verified by SciePro's Medical Advisory Board.