Osmic acid versus yttrium-90 in rheumatoid synovitis of the knee.

The effectiveness of osmic acid and yttrium-90 in the treatment of synovitis of the knee in rheumatoid arthritis is compared in 126 patients followed-up for 3 years. Ninety-one knees were injected with osmic acid and eighty-four knees with yttrium-90. Osmic acid appeared to be more effective than yttrium-90 throughout the period of the follow-up but the difference only reached statistical significance (p less than 0.05) at 3 years. Both therapies were well tolerated by patients and should be considered as an alternative to operative synovectomy.