Radiographic risk signs for loosening after cemented THA: 61 loose stems and 23 loose sockets compared with 42 controls.

The 1-year radiographs in 61 stems and 23 sockets, later revised because of aseptic loosening, were carefully examined for changes such as 1) separation of the lateral side of the stem from the cement, 2) radiolucent zones at the bone-cement interface, 3) fracture of the cement, 4) endosteal cavitation and 5) migration. They were compared with 42 clinically and radiographically successful primary total hip arthroplasties with 12-16 years follow-up. We found an increased risk of loosening in hips where radiolucencies appeared within the first postoperative year, whereas an unchanged radiographic appearance after 1 year strongly indicated that the risk of later loosening was small. Patients at risk should be followed indefinitely to detect progressive loosening and concomitant bone resorption in time.