Overview
what it is and why it mattersImage pendingAP ankle X-ray showing a bimalleolar fracture with displaced medial and lateral malleolar fractures and widening of the ankle mortise.
The ankle is a ring — a mortise formed by the lower ends of the tibia and fibula cradling the talus, the small bone of the hindfoot that sits between them. Like any ring, the ankle can tolerate a single break and still hold its shape, but once it is broken in two places the structure loses its ability to keep the talus centered, and the joint surfaces begin to slide out of alignment under load. Ankle fractures typically result from a twisting mechanism — rolling the foot inward or outward during a misstep off a curb or an athletic pivot — and the direction the foot twisted at the moment of injury dictates exactly where the bone breaks.
The decisive question in any ankle fracture is not simply whether a bone is broken, but whether the ring is stable: can the ankle hold the talus in position while it heals, or will the joint drift under body weight? Stability drives the decision between a boot and surgery far more than how dramatic the X-ray looks. A single break that leaves the mortise intact usually heals in a boot; a break that disrupts the ring in two places almost always needs to be fixed in the operating room to restore alignment.
Diagnosis & Evaluation
Evaluation begins at the bedside. The surgeon palpates the malleoli and the length of the fibula for tenderness, inspects the skin for blistering or tension, checks the neurovascular exam, and tests whether the patient can bear weight — the Ottawa Ankle Rules give a structured way to decide whether imaging is needed at all. Standard AP, lateral, and mortise X-rays characterize the fracture pattern and, most importantly, show whether the talus sits centered in the mortise. CT is added for complex pilon fractures, posterior malleolus involvement, or preoperative planning. When an isolated fibula fracture is found but the medial side of the ankle is tender, a gravity stress view or external rotation stress X-ray is used to unmask occult mortise instability that a resting film can miss.
Non-Surgical Treatment
Walking boot or short-leg cast
Stable isolated lateral malleolus fractures without mortise widening are managed in a removable boot with protected weight-bearing until the fracture is reliably painless and the X-ray shows healing.
Protected weight-bearing
Stable patterns tolerate early weight-bearing in the boot; unstable patterns or those at risk of displacement are kept non-weight-bearing until the surgeon confirms the fracture is holding position.
Serial imaging
Repeat X-rays out of the boot confirm the talus has not drifted. Any late displacement changes the plan toward surgery.
When Surgery Is Considered
Surgery is offered when the ankle cannot be trusted to hold its shape under body weight — any mortise instability, bimalleolar or trimalleolar patterns, talar shift on weight-bearing films, syndesmotic disruption, and open injuries. The goal is to restore the ring: fibular length and rotation, medial buttress, posterior-malleolar support, and syndesmotic alignment.
Ankle fracture ORIF is the primary operation, with plate-and-screw fixation of the fibula, screws or a small plate medially, and syndesmotic fixation when needed. Fractures that extend into the weight-bearing tibial plafond (pilon injuries) are typically coordinated through a regional Level-1 trauma center in San Antonio.
If non-operative care is not enough, these procedures are offered by the OSI team for this condition:
Providers Who Treat Ankle Fracture
Further Reading
authoritative sourcesExternal patient-education references and related OSI pages for additional background: