Midtarsal sprains are common injuries of the foot but are often under-recognized both clinically and radiologically. They commonly occur with lateral ankle sprains.
Epidemiology
In patients undergoing MRI for acute ankle trauma, up to 19% will have a midtarsal sprain 1.
Pathology
The mechanism of injury can be inversion (most common, up to 75%) +/- plantarflexion, or eversion 1,2.
Inversion-related fractures in midtarsal sprains occur in three main patterns 1:
-
lateral column distraction-related avulsion fractures
-
anterior calcaneal process
- bifurcate ligament
- extensor digitorum brevis (less common)
- dorsal calcaneocuboid: dorsal calcaneocuboid ligament
-
anterior calcaneal process
-
medial column impaction fractures
- sagittal navicular body fracture
- plantar talar head osteochondral fracture
- plantarflexion–related avulsion fractures
- dorsal talar head +/- dorsal navicular: dorsal talonavicular ligament
Eversion-related fractures in midtarsal sprains result in two main patterns 1:
- medial column distraction injuries
- navicular tuberosity: tibialis posterior avulsion / superomedial spring ligament
- lateral column impaction fractures
- calcaneocuboid joint impaction fractures