Osteoarthritis at the ankle joint is most commonly due to prior trauma, characterized by focal or asymmetric joint space narrowing and osteophyte formation. Commonly involved articular surfaces include the tibiotalar, subtalar, and talonavicular joints.
FINDINGS: No acute fracture. Ankle mortise is symmetric. Severe asymmetric tibiotalar joint space narrowing with posterior articular surface irregularity and prominent osteophytosis. Mild dorsal talonavicular and posterior subtalar joint degenerative changes.
IMPRESSION:
- Severe tibiotalar joint osteoarthritis.
- Mild talonavicular and posterior subtalar osteoarthritis.
Tarsal coalition is a common source of chronic pain. Look for classic signs of the two most common subtypes:
Calcaneonavicular coalition
- Fusion across anterior process of calcaneous and navicular
- "Anteater nose sign"
Talocalacneal coalition
- Fusion across middle subtalar articular facet
- "C-sign" and "Talar beak sign"