Crural Fascia

fascia cruris

The crural fascia is the deep investing fascia of the lower leg, encircling all compartments and attaching to the anterior tibial crest medially and the fibula laterally. It continues below as the extensor and flexor retinacula at the ankle and is continuous with the iliotibial band and patellar retinaculum above.

Region: Lower Leg

Biomechanics

Function & Actions

Contains the muscular compartments of the lower leg, transmits forces between compartments, and forms a pressure containment system that allows compartment syndrome to develop.

Clinical Relevance

Clinical Notes

The crural fascia is released in all approaches to lower leg fasciotomy. Fascial herniation through defects in the crural fascia is a common cause of lateral leg pain in runners, where the superficial peroneal nerve may be entrapped at the fascial exit point. The fascia is harvested as an autograft for tendon reconstruction.

Pathology

Common Injuries & Conditions

Fascial Herniation with Nerve Entrapment

Superficial peroneal nerve entrapment at a defect in the crural fascia producing activity-related lateral leg pain and dorsal foot numbness, treated by surgical fascial release at the herniation point.