Evaluation of two regimens to immobilise the knee after injections of yttrium-90.

Two regimens to immobilise the knee after injection were compared in patients receiving intra-articular yttrium-90 for persistent synovitis of the knee, the patients being randomly allocated to receive either complete bed rest or full mobilisation with the affected knee in a firm splint. There was no difference in the percentage of the radioisotope retained in the knee or in that taken up by other tissues between the two regimens. It is concluded that after intra-articular injections of yttrium-90 strict bed rest in hospital is unnecessary.