MRI VERSUS LATERAL STRESS RADIOGRAPHY IN ACUTE LATERAL ANKLE LIGAMENTINJURIES

Purpose: Our goal was to compare the abilities of MRI and stress radio graphy to detect the extent of recent lateral ankle ligament inversion injuries. Method: In this prospective study, 60 athletically active p atients (aged 18-45 years) with recent inversion trauma (less than or equal to 7 days) underwent stress radiography and MRI. In 15 patients, the MR findings were reviewed at surgery. Patients were divided into three groups according to severity of ligament injury on MRI (no, one, or two to three ligament tears). Based on bilateral stress radiograph y, patients were classified into three groups according to the differe ntial degree of talar tilt (less than or equal to 5, 6-14, or greater than or equal to 15 degrees) and compared with patients from the MR gr oups.Results: Surgery showed MRI to have 74% sensitivity and 100% spec ificity in the evaluation of complete lateral ankle ligament tears. Ag reement between MR and stress radiography groups for the severity of r ecent lateral ankle ligament tears was poor (kappa = 0.030). Conclusio n: MRI should be performed in young, athletically active patients if s urgical intervention is contemplated, especially at 6-14 degrees talar tilt on stress radiography, since stress radiography tends to over- a nd underestimate the severity of lateral ligament trauma.