The fibular neck is the constricted segment of the proximal fibula between the fibular head and the fibular shaft, approximately 3-4 cm in length. The common peroneal (fibular) nerve wraps around the fibular neck from posterior to anterior as it descends from the popliteal fossa, lying directly against the periosteum in the upper-third of the lateral leg. The peroneal muscles arise from the lateral fibular shaft just below the neck.
The fibular neck is the most common site of peroneal nerve injury in the lower limb, producing foot drop from weakness of the anterior compartment muscles. Causes include direct trauma, prolonged external pressure (crossed-leg sitting, plaster cast), fracture of the fibular neck or head, and tourniquet compression. Recovery depends on severity; neuropraxia resolves within weeks, while axonotmesis may take months. Fibular neck osteotomy is performed in high tibial osteotomy and fibular autograft harvest. Isolated fibular neck fractures occur in direct lateral leg impact.
Compression or stretch of the common peroneal nerve as it wraps the fibular neck produces foot drop from weakness of tibialis anterior, extensor digitorum longus, and peroneus tertius, with sensory loss over the dorsal foot and lateral shin, managed by removal of compressing casts, footdrop splint, and nerve decompression if no recovery within 3 months.
Direct blow to the lateral knee or associated with tibial plateau or knee dislocation fractures the fibular neck, with peroneal nerve injury in 10-15% of cases, managed conservatively unless associated with proximal tibiofibular instability requiring fixation.
