Radiology Coding Alert

Question: Documentation shows a bimalleolar fracture with posterior lip fracture. Which ICD-9 codes should I report? Texas Subscriber Answer: You should choose one of the following trimalleolar fracture codes for this diagnosis: • 824.6 -- Fracture of ankle; trimalleolar, closed • 824.7 -- ... trimalleolar, open. Reason: The documentation indicates a bimalleolar fracture, which means the patient fractured two malleoli ("bi-" means two). Typically this fracture involves the lateral and medial malleoli -- the bony projections on each side of the leg at the ankle. The radiologist also documents a fracture of the posterior lip, which is another term for the posterior malleolus. Fractures of the (1) lateral, (2) medial, and (3) posterior malleoli add up to a trimalleolar fracture ("tri-" means three). Less commonly, a trimalleolar fracture may involve the lateral, medial, and anterior malleoli. Open vs. closed: You'll base your trimalleolar code choice on whether the fracture was closed (the bone [...]