Ankle Fracture — ABOS Oral Boards Preparation
What examiners expect and how to prepare
Clinical Scenario
A 34-year-old right-hand-dominant male recreational basketball player presents to the emergency department after an inversion and external rotation injury to his left ankle during a game. He felt a pop and was unable to bear weight. He is otherwise healthy with no medical comorbidities, no prior injuries, and works as a software engineer. On exam, there is significant swelling and ecchymosis around the lateral and medial malleoli. The skin is tented over the lateral malleolus but intact. He has tenderness over the medial malleolus, the lateral malleolus, and the deltoid ligament. A squeeze test at the mid-calf is positive. Distal pulses are intact and neurologic exam is normal.
AP, lateral, and mortise views of the left ankle reveal a short oblique fracture of the distal fibula at the level of the syndesmosis (Weber B), a transverse fracture of the medial malleolus, and widening of the medial clear space to 6 mm on the mortise view. The tibial plafond is intact. Full-length tibia/fibula films show no proximal fibula fracture.
You performed open reduction and internal fixation of the bimalleolar ankle fracture. The lateral malleolus was fixed with a one-third tubular plate and the medial malleolus with two partially threaded cannulated screws. Intraoperative stress testing after fixation confirmed syndesmotic stability, so no syndesmotic fixation was placed. The patient was placed in a short leg splint, non-weight-bearing.
What Examiners Look For
- Data gathering: Describe the mechanism — supination-external rotation is the most common pattern, and you should be able to correlate mechanism to fracture pattern.
- Diagnosis: Systematic mortise view interpretation — talar shift, medial clear space, tibiofibular clear space, and tibiofibular overlap.
- Treatment plan: Why is this fracture unstable? How does medial-sided pathology (fracture or deltoid injury) change your surgical indication?
- Technical skill: Describe your fixation construct, plate position, and how you assess syndesmotic stability intraoperatively — external rotation stress, Cotton test, or direct visualization.
- Applied knowledge: Discuss the Lauge-Hansen and Weber classifications and how they guide treatment. What is the significance of a positive squeeze test?
- Complications: Post-operative wound complications, syndesmotic malreduction, and symptomatic hardware — how do you manage each?
Common Pitfalls
- Forgetting to examine the proximal fibula (Maisonneuve fracture) — this is a classic examiner trap.
- Not performing or describing intraoperative syndesmotic stress testing after fracture fixation.
- Citing specific biomechanical studies by name instead of describing the principles.
- Confusing Lauge-Hansen stages — know the progression cold or expect follow-up questions.
- Not discussing non-operative management criteria for stable injury patterns.
Key Classifications
Related Scenarios
Free — takes 3 minutes