Medial malleolar fractures

Fractures of the medial malleolus are the result of excessive abrupt tension of the medial collateral ligaments on the distal medial tibia caused by uneven loading or trauma to the lateral aspect of the tarsus.
The fracture leads to instability of the tarsocrural joint. Complete luxation of the joint is rare.
Clinical signs include lameness, joint effusion and swelling at the distal medial tibia region.

Tibial fractures usually develop as a result of trauma, such as kicks or falls. The exception to this are tibial stress fractures, which are an accumulation of cyclic loading and bone fatigue.

The most common types of tibial fractures are:

1. Salter Harris Type II
2. Tibial crest fractures
3. Simple diaphyseal fractures
4. Comminuted diaphyseal fractures
5. Diaphyseal stress fractures
6. Medial malleolus fractures
7. Lateral malleolus fractures
8. Distal physeal fractures

Radiography provides the most meaningful information as to location and configuration of the fracture(s).
In most cases 4 views at 45 degree intervals provide adequate information for an exact diagnosis. For the evaluation of the proximal tibia typically a lateromedial and a caudocranial projection each is enough.
Nuclear scintigraphy is useful in the identification of tibial stress fractures, which may be radiographically inapparent.

Diagnosis is by standard radiographic evaluation of the tarsus. Ultrasound evaluation is helpful to identify any associated soft-tissue injury, especially that to the medial collateral ligaments of the tarsus.