In a Grade III ankle sprain, which ligaments are compromised?

In a Grade III ankle sprain, complete rupture of the affected ligaments occurs, leading to significant instability of the ankle joint. Specifically, this type of sprain typically involves all key ligaments that provide stability to the lateral aspect of the ankle. The anterior talofibular ligament, calcaneofibular ligament, and posterior talofibular ligament are all compromised.

The anterior talofibular ligament connects the talus and fibula and is often injured in inversion injuries. The calcaneofibular ligament, which extends from the fibula to the calcaneus, is also commonly involved in this type of sprain. The posterior talofibular ligament, while less commonly injured, can be compromised in more severe sprains.

As a result, a Grade III ankle sprain is characterized by damage to all three of these ligaments, leading to the instability in the ankle that is consistent with this classification. This full rupture necessitates extensive rehabilitation and may require surgical intervention due to the loss of ligamentous support in the ankle, making option C the correct choice.

The other options reflect either partial involvement of the structures or focus on a single ligament, which does not align with the complete disruption seen in a Grade III