Stability Factors

• Tight fit of talus between the malleoli
• Strong ligaments
• Tendons bound in place by retinaculae

a) Configuration of articular bones

The two malleoli form a deep (socket-mortise) for the talus (tenon).This mortise is deepened posteriorly by the inferior part of the tibiofibular ligament (transverse tibiofibular ligament [p.t.f])

Note the following bones:

a) the tibia

b) the fibula

c) the talus

b) Collateral ligaments

Extends from medial malleolus to:

•  Neck of talus (deep part)
•  Tubercle of talus
•  Sustentacular tali of calcaneous
•  Spring ligament
•  Tuberosity of the navicular

It consists of three parts:

• Anterior talofibular ligament: Attached to the neck of the talus
• Calcaneofibular ligament: Attached to the lateral surface of calcaneous.
• Posterior talofibular ligament: Attached to the lateral tubercle of the talus.

Note:
Tendons crossing the joint are held in place by the retinaculae.