There is renewed interest in the all-polyethylene tibial component in total knee arthroplasty (TKA). Long-term results of this prosthesis in rheumatoid arthritis (RA) patients, however, are limited. Therefore, we studied 104 primary cemented all-polyethylene tibial TKA in 80 consecutive RA patients for up to 25 years to determine the long-term survival of all-polyethylene tibial components in patients suffering from end stage RA.
We estimated revision rates according the revision rate per 100 observed component years used in national joint registries. Kaplan-Meier was used to estimate survival curves.
During the 25-year follow-up, three revisions for tibial component loosening were performed. The mean revision rate of all-polyethylene tibial components with revision for aseptic loosening as the endpoint was 0.09 per 100 observed component years. This corresponds to a revision rate of 0.9% after ten years and 2.25% after 25 years. Survivorship according to Kaplan-Meier was 100% at ten years and 87.5% at 25 years [95% confidence interval (CI) 64.6-100)].
This study shows good long-term results of all-polyethylene tibial TKA in patients with RA. RA patients with multiple-joint inflammation may be less physically active than osteoarthritis patients, resulting in a lower demand on the prosthesis, and these patients may, indeed, be good candidates for all-polyethylene tibial TKA. Our results suggest that all-polyethylene tibial TKA could be a successful and cost-saving treatment for end-stage knee arthritis in RA patients.