Is radiation synovectomy for arthritis of the knee more effective than intraarticular treatment with glucocorticoids? Results of an eighteen‐month, randomized, double‐blind, placebo‐controlled, crossover trial

Objective To compare the clinical efficacy and safety of radiation synovectomy (RSO) with intraarticular (IA) yttrium-90 plus glucocorticoids (GCs) with the efficacy and safety of IA placebo yttrium plus GCs and to identify parameters that predict efficacy. Methods The knees of 97 patients with persistent arthritis despite outpatient treatment with IA GCs (n = 113 knees), were treated with either IA 90Y plus GCs (50%) or IA placebo yttrium plus GCs (50%), followed by 3 days of bed rest in the hospital clinic, with splinting of the treated knee. Predominant diagnoses were undifferentiated arthritis (39%) and rheumatoid arthritis (32%). The clinical effect of therapy was assessed at 6 months using a composite change index (CCI; range 0–12). The primary outcome measure was the response rate (i.e., the percentage of joints with a CCI ≥6). Knees with persistent arthritis after 6 months underwent crossover therapy (51% of the 90Y plus GCs group versus 45% of the placebo plus GCs group). Adverse effects and radiologic damage during followup were documented. Results Neither the response rate (48% in both groups), the mean CCI, nor the duration of remission was significantly different between groups. No clinically relevant short-term adverse effects were observed, except for progression of radiologic damage in 34% of the 90Y plus GCs group versus 28% of the placebo plus GCs group (knee prosthesis placement in 8% versus 1%). The functional and radiologic status at study entry predicted the clinical effect. Conclusion Treatment with 90Y plus GCs with bed rest and splinting is not superior to IA GCs with bed rest and splinting. Over the short term, both treatments appeared to be safe, although a negative effect of 90Y on cartilage and bone cannot be ruled out. Thus, it appears that RSO with 90Y should no longer be considered the treatment of first choice for persistent arthritis of the knee.