The treatment of persistent knee effusions with intra-articular radioactive gold: preliminary report.

Eighteen chronic knee effusions unresponsive to the usual methods of therapy were treated by intra-articular injections of radioactive gold ((198)Au) and followed up for one year. Ten patients had classical rheumatoid arthritis; three intermittent hydrarthrosis (both knees were treated in one patient); two ankylosing spondylitis, and one synovitis of undetermined cause. In 12 knees the effusion completely disappeared, usually within three months. Temporary increased pain and swelling occurred during the first week in five cases. Radiation dosimetry is discussed in detail.