Comprehensive Osteopathic Medical Licensing Examination (COMLEX USA) Practice

Which ligaments are primarily injured during an inversion ankle sprain?

1. Deltoid ligaments

2. ATF and PTF ligaments

3. CF and ATF ligaments

4. Supraspinatus ligaments

The correct answer is: ATF and PTF ligaments

Inversion ankle sprains occur when the foot rolls inward, placing stress on the lateral structures of the ankle. The ligaments that are primarily affected in this type of injury are the anterior talofibular ligament (ATF) and the calcaneofibular ligament (CF). The ATF ligament, located on the outside of the ankle, is the most commonly injured ligament in an inversion injury because it limits forward sliding of the talus on the fibula. When the ankle inverts, this ligament is placed under significant tension and can easily stretch or tear. The calcaneofibular ligament (CF), while not as commonly injured as the ATF in acute sprains, is also affected in more severe inversion injuries. Together, the ATF and CF ligaments support the stability of the ankle; therefore, when a significant inversion occurs, it is these two ligaments that typically bear the brunt of the force. In contrast, the deltoid ligaments, located on the medial side of the ankle, are more likely to be injured during eversion injuries, and the supraspinatus ligaments are unrelated to ankle injuries as they are part of the shoulder complex. Understanding the role of these ligaments in various ankle