Evaluation of Intra-articular Colloidal Gold Au 198 in the Treatment of Presistent Knee Effusions.

In the management of persistent knee effusions, synovectomy may be useful but surgical removal is often far from complete and recurrences are common. The present study reports an attempt to produce a radiation synovectomy, using the principle that colloidal Au 198, when injected into the knee joint, would behave like other particles and localize on the synovial membrane. Au 198 has a half life of 27 days and emits both beta and gamma rays; since the average range of the beta rays in tissue is approximately 1 mm., it was thought feasible that destruction of the superficial layers of the synovial membrane should occur if a sufficiently large radiation dose could be delivered.