This study was conducted to determine the prevalence of tendinosis and tears of gluteus medius and minimus muscles in patients presenting with buttock, lateral hip, or groin pain; describe the MR imaging findings; and discuss their probable relationship to the greater trochanteric pain syndrome.

Two hundred fifty MR imaging examinations of the hip were performed for the evaluation of buttock, lateral hip, or groin pain. The findings were reviewed for changes in the morphology or signal intensity of gluteus medius and minimus muscles and tendons and for any peritendinous abnormality including distention of regional bursae.

Thirty-five studies met our criterion of showing either tendinosis or tears of gluteus medius and minimus muscles as the primary positive finding. Eight patients had complete retracted tears of the gluteus medius, and 14 patients had partial tears; in 13 patients, MR findings were consistent with tendinosis. The gluteus minimus muscle was also involved in 10 patients. MR imaging findings were the same as those described for tears and tendinosis of other regions of the body. Surgical proof of a tendon tear was obtained in six patients.

Tendinopathy of the hip abductors and gluteus medius and minimus muscles was a common finding on MR imaging in our patients with buttock, lateral hip, or groin pain. Tendinopathy is probably a frequent cause of the greater trochanteric pain syndrome, a common regional pain syndrome that can mimic other important conditions causing hip pain including avascular necrosis and stress fracture. Moreover, it is likely that trochanteric bursitis is associated with tendinopathy.