Anatomy Msk · Year 1 · from Anatomy Msk
Case 3: Lateral Ankle Sprain
Clinical Image
Source: Wikimedia Commons - Ankle Sprain - CC BY-SA 3.0
Case Presentation
A 28-year-old recreational basketball player presents to urgent care after "rolling" her right ankle during a pickup game. She landed on another player's foot after a jump shot and felt her ankle turn inward. She heard a "pop" and experienced immediate pain and swelling over the outside of her ankle. She was able to bear weight initially but now cannot due to pain. Physical examination reveals significant swelling and ecchymosis over the lateral malleolus and anterolateral ankle. There is point tenderness over the anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL), but not over the medial malleolus, posterior tibial tendon, or base of the fifth metatarsal. Anterior drawer test demonstrates increased anterior translation compared to the uninjured side, suggesting ATFL tear. Talar tilt test is equivocal. Ottawa ankle rules indicate no need for X-rays since she can bear weight for 4 steps and has no bony tenderness at specific locations. She is diagnosed with a Grade II lateral ankle sprain (partial ligament tear) and treated with RICE protocol, ankle brace, and physical therapy. This case demonstrates the vulnerability of the lateral ankle ligaments.
Key Learning Points
- The ankle is a synovial hinge joint (uniaxial) allowing dorsiflexion and plantarflexion
- The lateral ankle ligaments (ATFL, CFL, PTFL) are weaker than the deltoid ligament complex medially
- Inversion injuries stress the lateral ligaments; the ATFL is most commonly injured (weakest, taut in plantarflexion)
- Joint sprains involve ligamentous injury: Grade I (stretch), Grade II (partial tear), Grade III (complete rupture)
- Ottawa ankle rules guide appropriate use of radiography in ankle injuries