tibionavicular

The tibionavicular ligament is a component of the medial collateral (deltoid) ligament complex of the ankle. It originates from the medial malleolus of the tibia and extends to the navicular bone, typically attaching at or near the navicular tuberosity. It is generally described as part of the superficial layer of the deltoid ligament, alongside other fibers such as the tibioncalaneal portion, and it contributes to the overall stabilization of the medial ankle.

Functionally, the tibionavicular portion helps resist eversion and abduction of the foot at the ankle and supports the medial aspect of the joint. By linking the tibia to the navicular, it plays a role in maintaining the medial longitudinal arch during weight bearing and locomotion. The ligament works in concert with other components of the deltoid complex to minimize excessive movement that could lead to instability or injury.

Clinical significance includes its involvement in eversion ankle sprains, where the tibionavicular portion can be stretched or torn, often in combination with other deltoid ligaments. Injuries may present with medial ankle tenderness and swelling and can be evaluated with magnetic resonance imaging or ultrasound. Radiographic findings of associated injuries, such as widening of the medial clear space or navicular involvement, may accompany tibionavicular damage.

Anatomical variations exist in insertional details, with some fibers occasionally extending to adjacent aspects of the navicular or plantar surfaces. Overall, the tibionavicular ligament is a key stabilizing structure of the medial ankle, integral to maintaining joint congruence and arch support. See also deltoid ligament.