Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Although ceramic implants have been in use for many years and they are intended to minimize wear debris it is unknown whether alumina-on-alumina or alumina-onpolyethylene produce less wear and osteolysis. We therefore investigated wear and osteolysis on 28 bilateral arthroplasties (one ceramic-ceramic and the contralateral ceramic-polyethylene) of patients who had survived 20 years without revision and without loosening of either hip. Osteolysis was identified on anteroposterior pelvic radiographs and 3-D volume from CT scans. The number of osteolytic lesions detected with CT scan was higher than with radiographs. The number of lesions was higher on the side with the alumina-PE couple. With a similar length of followup on each side, the surface and the volume of osteolysis were consistently higher on the side with the alumina-PE couple. We found no correlation between the volume of osteolysis and the volume of estimated wear in each couple of friction. Hips with osteolysis had a lower Harris score.

Abstract:The treatment of bone a vascular necrosis is a big challenge considering the youthfulness of the patients involved by necrosis in sickle cell disease and the importance of the generated disability. A vascular osteonecrosis is an epiphysis pathology which could be treated by joint replacement with success, however, multiple surgical procedures are mostly necessary during the patient's life with a hazardous long term functional results. The treatment by autologous bone marrow grafting is an effective alternative which preserve the native joint. Using this mini-invasive high technology surgical treatment in early stages, a joint replacement could be avoided in many patients.

Background THA performed in patients with cognitive deficits or neuromuscular diseases has been associated with a high postoperative dislocation rate. The constrained liner reportedly provides stability in patients with recurrent dislocation. However, achieving stability could be offset by early loosening when used in patients with neurologic diseases. Questions/purposes We therefore asked whether constrained liners had a higher risk of loosening when used in primary THA for patients with neurologic diseases. Methods We retrospectively reviewed a 144 patients (164 hips) with neuromuscular disease who had a constrained polyethylene insert from 1999 to 2004 and compared them to another 120 patients (132 hips) with neuromuscular disease operated on immediately before this period (from 1994 to 1998) who had a conventional polyethylene insert. Results Thirty-three (25%) of the 132 hips without a constrained liner were known to have had at least one dislocation and 21 had revision for recurrent dislocation. Ten other hips had revision for loosening of the cup. The survival rate was 82% at 5 years and 77% at 10 years with revision due to recurrent dislocation or loosening of the cup as the endpoint. With a constrained liner, at minimum 5-year followup (mean, 7 years; range, 5-10 years), the incidence of complications, particularly dislocation, was decreased (three dislocations among 164 hips; 2%), with one revision for recurrent dislocation and one revision for loosening. Conclusions This constrained acetabular component provides durable protection against dislocation without substantial increased loosening at midterm followup. Level of Evidence Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.