MRI OF THE SINUS TARSI IN ACUTE ANKLE SPRAIN INJURIES

Purpose: Our goal was to evaluate the visibility and incidence of trau matic abnormalities of the sinus tarsi in patients with acute ankle sp rain injuries and compare these findings with the extent of lateral an kle ligament injuries on MRI. Method: Sixty athletically active patien ts (aged 18-45 years) with recent inversion trauma (less than or equal to 7 days) underwent MRI. Replacement of fat tissue in the sinus tars i was recorded. Inter/intraobserver agreement was calculated (kappa-st atistics). Injuries of the three lateral ligaments, evaluated by MRI, were graded according to partial (1 point) or complete (2 points) tear s for each of three lateral ligaments (together 0-6 points) and were c ompared with sinus tarsi abnormalities. Results: In 26 patients (43%), replacement of sinus tarsi fat tissue was depicted by MRI. Inter/intr aobserver agreement for MR changes of the sinus tarsi was good to mode rate (kappa = 0.675/0.584). Grade of lateral ankle ligament injury sho wed a statistically significant difference (p = 0.033) between the two sinus tarsi groups (normal/abnormal). Conclusion: Acute ankle sprain injuries, evaluated by MRI, are associated with acute abnormalities of the sinus tarsi in 43% of patients and correlate with the extent of l ateral ankle ligament tears.