Abstract
We investigated 14 patients (15 hips) undergoing total hip arthroplasty (THA) for rheumatoid arthritis (RA) and rheumatic disease from October 2005 to December 2008. The subjects were 11 patients with RA, one patient with RA who had a neck fracture of femur, one patient with systemic lupus erythematosus, one patient with periarteritis nodosa, and one patient with aortitis syndrome. The mean age at surgery was 68 years (51-81 years). The average follow-up period was 2.1 years (8 months-3.8 years).
15 hips were treated with a Dorr cortical bone subtype, type A (all cementless THA), 10 hips with Dorr type B (2 cemented, 3 hybrid and 5 cementless THA), and 4 hips with Dorr type C (all hybrid THA). Neither cemented nor cementless cups showed migration or loosening by Moore's estimation. All cementless stems were bony stable by Engh's estimation. One case treated with a cemented stem showed an increase of the radiolucent line. The average point score of the Japanese Orthopaedic Association (JOA) scoring system improved from 33.5 to 77.7, but the activity of 20％ of the patients had declined at the latest follow-up.
Both hybrid and cementless THA showed good short-term results, but clinically the level of activity declined in patients who suffered major joint involvement and/or had steroid induced depression.
