An evaluation of repeat intra-articular injections of yttrium-90 colloids in persistent synovitis of the knee.

The effectiveness of a second intra-articular injection of yttrium-90 colloid was studied in 30 patients with persistent synovitis of the knee. All had responded poorly to a first injection of yttrium-90 yet seemed likely to benefit from this therapy. With a minimum review period of 6 months complete remission of synovitis was obtained in 20%, while 63% gained symptomatic relief, with some reduction of synovitis. No improvement occurred in 17%, and in this group generalised disease activity was more apparent.