Syndesmosis Sprain

1. What is the ankle syndesmosis?
2. How does a syndesmosis sprain occur?
3. What is the clinical picture of a syndesmosis sprain?
4. What imaging is required to diagnose a syndesmosis sprain?
5. What is the treatment of syndesmosis sprain?

Answers:
1. Fibrous joint keeping together tibia and fibula that maintains integrity of ankle, made up of four ligaments.
2. Hyperdorsiflexion and forceful eversion, or direct blow to foot with ankle in external rotation.
3. Chronic pain and swelling in anterior ankle. Positive squeeze test (tenderness on compression of distal tib-fib) and stress test (knee at 90 deg, ankle neutral, pain with forceful ext rot of foot).
4. Plain films to r/o tib-fib widening and r/o Maisonneuve fx (prox fibula fx resulting from ruptured anterior tibiofibular ligament).
5. Conservative treatment is usually used. Surgical treatment includes a screw to stabilize ankle mortise.