Combined Arthroscopic and Radiation Synovectomy of the Knee Joint in Rheumatoid Arthritis: 14-Year Follow-Up

Purpose: To investigate the long-term outcome of combined arthroscopic and radiation synovectomy of the knee joint in early cases of rheumatoid arthritis (RA) with regard to knee function and the need for surgical re-interventions. Methods: Between 1993 and 1997, a consecutive series of 38 RA patients with therapy-refractory synovitis of the knee joint and only mild cartilage lesions (not exceeding Outerbridge grade II at surgery) were treated with combined arthroscopic and radiation synovectomy. Knee function was assessed preoperatively; at 6 months, 1 year, and 5 years; and finally, at a mean of 14 years with 4 different functional scores. A Kaplan-Meier survival curve was calculated with "any re-intervention" and "total knee arthroplasty" as endpoints. Results: Of 38 knees, 32 were available for the final 14-year follow-up with a total of 22 re-interventions: intra-articular steroid injection (n = 3), arthroscopic (n = 2) or radiation (n = 1) re-synovectomy, and total knee arthroplasty (n = 16). The remaining 10 patients with no re-intervention showed knee function not significantly different from the postoperative state. With any surgical re-intervention as the endpoint, the survival rate was 84% at 5 years (95% confidence interval [CI], 67.0% to 86.7%), 44% at 10 years (95% CI, 26.7% to 60.0%), and 32% at the 14-year assessment (95% CI, 16.0% to 49.3%). With total knee arthroplasty as the endpoint, the joint survival rate was 88.5% at 5 years (95% CI, 68.5% to 96.2%), 53.9% at 10 years (95% CI, 33.3% to 71.6%), and 39.6% at 14 years (95% CI, 18.9% to 48.6%). Conclusions: Combined arthroscopic and radiation synovectomy leads to a stable improvement of knee function for a minimum of 5 years, but surgical re-interventions were frequently observed at the 14-year assessment and challenge the long-term benefit of the procedure. Patients with no interventions had a significantly shorter history of disease (7 v 11 years). Level of Evidence: Level IV, therapeutic case series.