Most ankle fractures are isolated malleolar fractures, but bimalleolar and trimalleolar fractures occur in up to one-third of cases. While there are numerous classification systems, the simplest is based on the radiographic appearance of these malleoli.
Management and Disposition
Essential treatment is directed at stability and exclusion of associated injuries. Neurovascular status (deep peroneal, superficial peroneal, medial and lateral plantar nerves, posterior tibial artery, and dorsalis pedis artery) should be assessed. The entire length of the fibula, including the proximal portion should be palpated to rule out additional fractures. All ankle fractures, except for fibular avulsions, require immobilization by cast or reduction followed by casting. Except for unimalleolar fractures, most require open reduction and fixation; thus, orthopedic consultation is recommended. In the ED, fractures should be splinted with a posterior mold, kept non–weight bearing, elevated, and iced for 24 hours. Appropriate analgesia and consultation are addressed. The overall goal is to restore anatomic relationships, maintain them during healing, and institute early mobilization. Complications, although rare, include skin necrosis, osteomyelitis, osteoarthritis, and malunion.
Trimalleolar Ankle Fracture. (A-C) A tiny avulsion fracture of the medial malleolus tip, an oblique fracture of the lateral malleolus, and an oblique fracture of the distal tibia’s posterior lip. (D-E) Reformatted CT images nicely demonstrate the same fractures. (Reproduced with permission of Block J, Jordanov MI, Stack LB, Thurman RJ. The Atlas of Emergency Radiology. New York, NY: McGraw Hill; 2013.)
Postreduction arthritis can occur in up to 30% of cases.
Avulsion fractures may be treated as stable ankle sprains if they are less than 3 mm in diameter, they are minimally displaced, and there is no evidence of significant ligamentous injury.