[Degenerative rupture of the hip abductors. Missed diagnosis with therapy-resistant trochanteric pain of the hips and positive Trendelenburg sign in elderly patients].

The cases of four elderly patients with persistent trochanteric pain and tears of the gluteus medius and/or gluteus minimus tendons detected in magnetic resonance imaging (MRI) are presented. There was no history of local trauma in any patient but three patients had a positive Trendelenburg sign. Magnetic resonance imaging showed either an obvious discontinuity of the affected tendon or an increased T2 signal above, or less specifically lateral to the greater trochanter. The presence of an elongated tendon on MRI is most likely indicative of a partial rupture of the tendon. Pain and local tenderness over the lateral aspect of the hip in clinical examination is commonly attributed to trochanteric bursitis or trochanteric pain syndrome. Partial or complete tears of the gluteus medius and/or gluteus minimus tendons are thought to represent an unusual finding. However, the true incidence and the clinical significance of hip abductor degeneration and rupture remain to be determined. More studies are needed to examine the prevalence of ruptures in asymptomatic patients, to evaluate the subsequent risk for developing osteoarthritis of the hip (caused by impaired protective reflexes originating from proprioceptive nerve endings in muscle spindles) and to determine the risk for falls related to weakness of hip abduction. Furthermore, no data exist regarding the success rate of conservative treatment. Tears of the gluteus medius and minimus tendons in the elderly population are likely to be a more common cause of pain in the greater trochanteric region than previously thought. In patients who do not respond to conservative treatment, weakness of hip abduction (positive Trendelenburg sign) and new limping should point to the possibility of hip abductor ruptures. The most useful examination technique for diagnosis is MRI.