calcaneofibularis

The calcaneofibular ligament, also called the calcaneofibularis and in Latin as ligamentum calcaneofibulare, is a ligament of the lateral collateral ligament complex of the ankle. It extends from the distal fibula, near the lateral malleolus, to the calcaneus on the lateral aspect of the foot, spanning the talocrural joint.

Anatomy and relations: The ligament runs obliquely from the fibula to the calcaneus and lies on the lateral side of the ankle, contributing to stability of the ankle joint. It is encountered in conjunction with the other lateral ligaments, including the anterior talofibular and posterior talofibular ligaments. In many individuals it may have variable anatomical bands.

Function: The calcaneofibular ligament helps stabilize the ankle against inversion of the foot. It tightens with lateral (inversion) stress and thus contributes to lateral ankle stability, particularly when the foot is in neutral to plantar flexion.

Clinical significance: Injury to the calcaneofibular ligament occurs in ankle sprains, especially those involving inversion of the foot. It may be torn alone or in combination with the other lateral ligaments, most notably the anterior talofibular ligament. Chronic CFL insufficiency can contribute to recurrent lateral ankle instability and may require prolonged rehabilitation or surgical intervention in selected athletes.

Diagnosis and treatment: Evaluation typically includes a physical examination focused on lateral ankle stability, with tests such as the talar tilt test, and imaging such as MRI to assess ligament integrity. Management ranges from conservative care (rest, immobilization, physical therapy) to surgical repair or reconstruction for persistent instability or in high-demand activities.