Objective: The purpose of our study was to determine the accuracy of MRI for diagnosing tears of the hip abductor tendons (gluteus medius and gluteus minimus) and to evaluate various signs of tendon disruption.
Materials and methods: We retrospectively evaluated MRIs of 74 hips (in 45 patients) that were obtained using 35- to 42-cm fields of view and interpreted using primary and secondary signs of tendon disruption. Fifteen hips had surgically proven abductor tendon tears, and 59 hips were either asymptomatic or had surgically confirmed intact tendons. MRI findings were scored by two radiologists through consensus and then again independently by a third radiologist to determine interobserver agreement.
Results: The accuracy of MRI for the diagnosis of tears of the abductor tendons was 91%. Statistically significant associations were found between tears of the abductor tendons and areas of high signal intensity superior to the greater trochanter on T2-weighted images (p < 0.0001), tendon elongation in the gluteus medius (p = 0.0028), tendon discontinuity (p = 0.016), and areas of high signal intensity lateral to the greater trochanter on T2-weighted images (p = 0.0213). Interobserver agreement was good to fair.
Conclusion: MRI showed good accuracy for the diagnosis of tears of the gluteus medius and gluteus minimus tendons. The identification of an area of T2 hyperintensity superior to the greater trochanter had the highest sensitivity and specificity for tears at 73% and 95%, respectively.