Fixation of total hip components in rheumatoid arthritis and arthrosis. A radiographic, roentgen stereophotogrammetric, densitometric and histomorphometric study

摘要

The radiographic survival of the Charnley prosthesis was studied in two retrospective, matched-pair cohorts of rheumatoid arthritis (RA) and arthrosis (OA) patients. In RA, the 7-year radiographic socket survival improved from 87% to 96% after the introduction of flanged sockets, bone transplants in cases of acetabular protrusion and the rejection of the pilot hole technique. In OA the 10-year radiographic socket survival was 95%. In both groups the 7-year radiographic stem survival improved from 80% to 96% following the introduction of the new cementing technique. Migration of the Charnley prosthesis in the first two years was evaluated by roentgen stereophotogrammetric analysis (RSA) in RA and OA patients, and related to the histomorphometric characteristics of trabecular bone in the acetabulum and the femur. In RA, sockets migrated six times more in the proximal direction as compared with OA; there was no difference in migration in other directions. Stem fixation was equally secure in RA and OA. RA cases had more osteoid in both the femur and the acetabulum, but the amount of osteoid was not correlated with the degree of migration. The bone mineral content (BMC) of RA and OA hips was assessed by dual photone roentgen absorptiometry prior to hip replacement. Patients with RA had 20% less BMC than those with OA but there were no signs of a relative peri-acetabular deficit. In two randomized trials of 81 OA patients, migration of the uncemented, Harris-Galante type I socket was evaluated by RSA and compared with Charnley sockets. After a minimum follow-up of 2 years, no difference in migration between the two socket designs was found. 98 refs, 18 figs, 2 tabs. (Atomindex citation 26:005690)