Hip radiographs were examined in forty patients with rheumatoid arthritis who had total hip arthroplasties. The patients' ages ranged from 37 to 83 years.
Radiological appearances of hip involvement was calssified into five types as described by Lowe et al. Radiographic evaluation showed that protrusio acetabuli and loss of joint space were seen in 45% and 28%, respectively. Types of hip involvement correlated with the serum level of CRP and type of joint destruction (LES, MES, MUD), but not with disease duration, maintenance dose of corticosteroids and JOA score. 70% of the patients with protrusio acetabuli were MUD type and most with loss of joint space were LES or MES type.