[Long-term results after cemented total hip arthroplasty in chronic polyarthritis]

As a part of long-term follow up (I) of 544 cemented Müller-curved stem total hip replacements (THR), implanted 1977 to 1983, 207 THR in 163 patients with rheumatoid arthritis (RA) were evaluated 9 to 15 years (11 on an average) postoperatively. The feed back rate was 96.9% so the results are very reliable. 18 cups were loosened (13 already changed), but no stem had to be changed for aseptic loosening. 2 THR (1.0%) had to be revised because of deep infection. Survival rate of Kaplan and Meier for aseptic loosening was 94.6% after 10 years, 83.5% after 15 years. The ARO multi-center-study 1995 (II) includes 3113 THR implanted 1987 and 1988. Within a follow-up period of 7 to 9 years the over all rate of aseptic changing for cemented cups (1.4%) was significantly lower than for uncemented cups (2.9%)--in RA even 1% versus 5.7%. The corresponding rates for stems was 1.0% (cemented) versus 1.8% (uncemented). We contributed 110 THR in 94 patients with RA with feed back of 100%. Because of deep infection one THR had to be changed and two were explanted. But no change of cup or stem because of aseptic loosening was observed. Also in the literature survival rates up to 97% after 10 years or 77% after 25 years even in younger patients with RA can be stated.

Cemented THR shows good long-term-results in RA which with uncemented designs have also to be proved. As a consequence of analysing the (few) failures the cemented THR of Wessinghage with optimized bone-cement-implant-compound was introduced. We demand a high feed back rate in long-term follow-ups also with respect to quality management and comparing data.