In a prospective study of 176 consecutive patients who underwent total hip arthroplasty for osteoarthritis, we identified 34 (20%) with degenerative pathology of the abductor mechanism. These degenerative tears were commoner in elderly women. The hip capsule usually was involved, but in 6 patients (16%), the gluteus minimus or medius tendons were involved in isolation. These abductor mechanism tears are progressive in nature and the result of degenerative processes.