1. The results of twenty-eight synovectomies and débridements in adults and three synovectomies in children are discussed. Eighty-five per cent of the procedures in adults were performed in late stages of destruction. All adult patients had classic rheumatoid arthritis with multiple joint involvement. Seventy-nine per cent of the knees were rated improved by the patient as compared with 65 per cent rated improved by the examiner. In 46.5 per cent definite or probable recurrence was found.
2. The results and the incidence of recurrence were found to be time dependent and proportional to the general activity of the disease as well as to the extent of damage present at the time of operation. When synovectomy was done bilaterally at an identical stage of the disease, the results were comparable.
3. Scoring of a patient's disability and local disease activity were found to be very useful in order to evaluate the results quantitatively.
4. Joint instability and joint narrowing were used as the criteria of the extent of joint damage and were found to be reliable in predicting the chances of success of synovectomy in a patient with low or moderate disease activity.
5. Angular deformity, antedating rheumatoid involvement, tends to progress rapidly with the onset of arthritis and should probably be corrected early.
6. Recurrence does not always become apparent during the first few months after synovectomy.
7. In advanced stages of destruction the objective of synovectomy is temporary relief of pain and functional improvement. Synovectomy alone is not indicated when there is severe instability and loss of articular cartilage.
8. Synovectomy is strongly indicated for a knee which has shown persistent involvement of short duration when there is advanced joint destruction of the opposite knee.
9. With early mobilization, the range of motion is not significantly affected and does not correlate with the final subjective and objective result in most patients.
10. Only two complications occurred: one a separation of the patellar tendon and the other, thrombophlebitis.