Diagnosis

Transsyndesmotic fibular fracture, with medial lesion and fracture of the posterolateral rim (Volkmann) (AO/OTA 44B3) 

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The most common injury pattern occurs with axial loading of a supinated foot as described for 44B1 and 44B2 fractures. Progressive talar external rotation results in further opening of the fibular fracture, with posterior displacement of the lateral malleolus. Finally the talus exits the ankle mortise posteriorly and disrupts the medial collateral structures. In some cases, as the talus dislocates posteriorly out of the mortise, it fractures the posterior tibial rim (Volkmann's fracture). These are classified as AO/OTA 44B3.

Complete radiological evaluation (AP, lateral and AP with internal rotation) is crucial for correct classification and decision making.

Options
1. Simple, with ruptured medial collateral ligament (AO/OTA 44B3.1) 
2. Simple, with fracture of the medial malleolus (AO/OTA 44B3.2) 
3. Multifragmentary, medial malleolus fractured (AO/OTA 44B3.3) 

1. Simple, with ruptured medial collateral ligament (AO/OTA 44B3.1) 

Simple, with ruptured medial collateral ligament (AO/OTA 44B3.1)

Simple, with ruptured medial collateral ligament (AO/OTA 44B3.1)

If there is a simple, oblique fibular fracture at the level of the syndesmotic ligaments, associated with a posterior malleolar fracture, and the injury on the medial side is a rupture of the deltoid ligament, this is classified as an AO/OTA 44B3.1 fracture.

The fracture of the posterior tibia may be a small cortical avulsion. Much more common is a larger compression fracture, the fragment bearing a variable area of the posterior articular surface.

The anterior syndesmotic ligament is ruptured, or it may be avulsed, either at its fibular (Le Fort / Wagstaff), or tibial (Tillaux-Chaput) insertion).

2. Simple, with fracture of the medial malleolus (AO/OTA 44B3.2) 

Simple, with fracture of the medial malleolus (AO/OTA 44B3.2)

Simple, with fracture of the medial malleolus (AO/OTA 44B3.2)

If there is a simple, oblique fibular fracture at the level of the syndesmotic ligaments, associated with a posterior malleolar fracture, and a medial malleolar fracture, this is classified as an AO/OTA 44B3.2 fracture.

The fracture of the posterior tibia may be a small cortical avulsion. Much more common is a larger compression fracture, the fragment bearing a variable area of the posterior articular surface.

The anterior syndesmotic ligament is ruptured, or it may be avulsed, either at its fibular (Le Fort / Wagstaff), or tibial (Tillaux-Chaput) insertion.

3. Multifragmentary, medial malleolus fractured (AO/OTA 44B3.3) 

Multifragmentary, medial malleolus fractured (AO/OTA 44B3.3)

Multifragmentary, medial malleolus fractured (AO/OTA 44B3.3)

If there is a multifragmentary fibular fracture at the level of the syndesmotic ligaments, associated with a posterior malleolar fracture, this is classified as an AO/OTA 44B3.3 fracture.

The fracture of the posterior tibia may be a small cortical avulsion. Much more common is a larger compression fracture, the fragment bearing a variable area of the posterior articular surface.

This is usually associated with a medial injury, either a rupture of the deltoid ligament, or a fracture of the medial malleolus.

One of the fibular fragments may represent the detachment of the tip of the main proximal fibular fragment. This usually bears some intact portion of the anterior syndesmotic ligament. It may become entrapped between the other fibular fragments.