Presentation
Ankle pain and anterolateral ankle impingement one-year post injury.
Patient Data
Anterior talofibular ligament is scarred and mildly wavy with a small anterior osteophyte at the distal fibula / anterior talofibular ligament origin. Calcaneofibular ligament is scarred.
Deltoid ligament is intact. Superomedial spring ligament is thickened distally. Dorsal talonavicular and bifurcate ligaments are both scarred.
No osteochondral injury of the talar dome or distal tibial plafond.
Small avulsion fractures from the anteromedial lateral malleolus at the origin of the anterior talofibular ligament.
Case Discussion
The MRI demonstrates prior lateral collateral, spring ligament complex and midtarsal ligamentous injuries, now with scarring. The anterior talofibular ligament in particular is both thickened and wavy with an osteophyte at the site of prior avulsion fractures. This osteophyte is the likely cause of anterolateral ankle impingement given the lack of other causes, which more commonly is traumatic synovitis forming a fibrous mass.