Anatomy of the Foot & Ankle

Ligaments of the Ankle Joint

Stability of the ankle joint depends on: 

1. Ankle position -determines the orientation of ligaments
2. Applied load (weightbearing) - instability occurs during loading or unloading. 
3. Ligament complexes

A. Medial Ligaments (See Figure 1)

The deltoid ligament stabilizes the ankle medially. Superficial and deep layers of the deltoid ligament may independently prevent valgus talar tilting. 

B. Lateral Ligaments (See Figure 2)

The anterior talofibular ligament (ATFL), calcaneofibular ligament (CFL), and posterior talofibular ligament (PTFL) all contribute to
alleviate anterior drawer stress in the nonaxially loaded ankle, as well as adduction (varus talar tilting) stresses in the plantarflexed, neutral, and dorsiflexed
ankle/subtalar complex. 

Rotatory stability of the ankle joint is determined by:

1. the collateral and syndesmosis ligaments
2. fit of the talus in the mortise
3. shape of the articular surfaces in the loaded condition 
4. the ATFL, CFL and PTFL in the loaded ankle 
5. the deltoid and syndesmosis ligaments
   

Ligaments of the Subtalar Joint

The CFL is a primary stabilizer of the subtalar joint that traverses the lateral side of the posterior facet articulation. 

The cervical ligament is the strongest ligament connecting the talus and calcaneus, and extends from the inferior aspect of
the talar neck, across the sinus tarsi, to the dorsum of the neck of the calcaneus.