Rheumatoid Arthritis of the Hip.

The hip joint may be affected in 15% to 28% of all patients with rheumatoid arthritis. Radiographic evidence of involvement includes periarticular osteopenia, cystic changes, and a variable amount of progressive protrusio acetabuli. Histomorphometric study has shown increased bone turnover in acetabular biopsy specimens from rheumatoid patients undergoing total hip arthroplasty. Due to the relative fragility of bone in these patients, there is an increased risk of fracture of the proximal femur due to minor trauma, and a high rate of loss of fixation has been reported. Total hip arthroplasty has been successful in the treatment of severe rheumatoid arthritis of the hip in patients of all ages. Special attention should be paid to the cervical spine and the patient's medical treatment regimen during the preoperative evaluation. Cemented total hip arthroplasty has been associated with a higher prevalence of late infection and acetabular component loosening in rheumatoid patients than in osteoarthritic patients. Loosening of cemented components is accelerated in patients with juvenile rheumatoid arthritis. Several short-term studies have documented successful early results with noncemented components in patients with rheumatoid arthritis; however, longer-term studies are necessary to determine whether the improvements in function and survival are greater than with cemented components.