2014 年 26 巻 1 号 p. 57-61
We investigated hip joint destruction in patients with rheumatoid arthritis before and after the availability of methotrexate and biological disease-modifying anti-rheumatic drugs (DMARDs) in Japan. A total of 35 patients with 45 diseased joints underwent total hip arthroplasty from 1995 to 1999 (Group A: 21 hips in 15 patients) and from 2006 to 2010 (Group B: 24 hips in 20 patients). We monitored the oral administration of therapeutic drugs and prednisolone, measured preoperative C-reactive protein (CRP) levels, estimated the Larsen grade and bone defects of the acetabulum floor using simple X-ray images, and calculated the bone defect rate of the femoral head. The intake of preoperative oral prednisolone was significantly less in Group B than in Group A (P < 0.05), as were preoperative CRP levels (P < 0.05). There was no difference in Larsen grade between the groups. Type III (combined type) bone defects of a large size in the acetabulum base were observed in the hip joints of 12 hips in Group A (57.1%) and 10 hips in Group B (41.7%), and the mean rate of bone defects in the femoral head was 26.7% in Group A and 33.7% in Group B. These findings indicated that the recent introduction of effective medical treatment has decreased the number of patients with large bone defects in the acetabulum. Furthermore, the number of patients subjected to total hip arthroplasty for rheumatoid arthritis accompanied by severe hip joint destruction has decreased. However, the number of patients who underwent total hip arthroplasty was slightly higher in this study, indicating that even if the disease activity of rheumatoid arthritis is suppressed, joint destruction may continue in the hip joint of patients with previously recognized mild joint destruction.
