THE PATTERN OF BONE AND CARTILAGE DAMAGE IN THE RHEUMATOID KNEE

Synovectomy has become a common operation in the treatment of rheumatoid arthritis of the knee. The surgeon thus has a unique opportunity to inspect the macroscopical features at various stages of the disease process. In particular the early morphological changes can be studied in fresh material, even before radiological signs have appeared. Fifty consecutive cases of synovectomy of the knee were studied at operation in order to determine whether there is any constant pattern in the changes seen at synovectomy and, if so, to assess how the pattern is related to I) the duration of symptoms in the knee; 2) the macroscopic appearance and volume of the synovium removed; and 3) the presence and type of fibrinous bodies. MATERIAL Fifty synovectomies performed at the Rheumatism Foundation Hospital were studied. All patients had rheumatoid arthritis fulfilling the criteria ofthe American Rheumatism Association, and all had had a previous course of medical treatment including, in forty-four cases, an intra-articular injection of osmic acid, without clinical improvement. The method of synovectomy was standard in all cases. It was done through two parapatellar incisions. The volume of synovium removed was measured immediately before any shrinkage by drying. A record of the bone and cartilage lesions seen at operation was made in “map” form. This information was added to the clinical findings and later transferred to a punch-card for detailed analysis. There were eleven male and thirty-nine female patients. The average age at operation was forty-five years. with a range from seven to fifty-nine years