Deltoid ligament abnormalities in chronic lateral ankle instability.

Background: Treatment of patients with repeated ankle sprains and chronic lateral ankle instability tends to focus on the lateral collateral ligaments. We reviewed records to ascertain the prevalence of abnormalities of the deltoid ligament in this population.

Methods: Retrospective review of MR images and surgical reports was performed for all patients during a 3-year period that underwent surgical treatment of chronic ankle instability at a single institution. Forty-seven ankles (46 patients) met inclusion criteria. None had medial ankle pain.

Results: On MRI, all patients had anterior talofibular ligament tear, plus injury to one or more additional ligaments. Ninety-one percent had injury of calcaneofibular ligament. Injury to the posterior talofibular ligament was less common (49%). Deltoid ligament injuries were seen in 72% of cases (23% superficial deltoid only, 6% deep deltoid only, 43% both superficial and deep components). Of patients with injury to the superficial deltoid, 32% had an intact deep deltoid ligament. MRI correlated well to surgical findings.

Conclusions: Deltoid ligament injuries were common in patients with lateral ankle instability who underwent reconstruction.