Consequences of synovectomy of the knee joint: clinical, histopathological, and enzymatic changes and changes in 2 components of complement.

The state of 36 knee joints of 32 rheumatic patients was evaluated after surgical synovectomy, the follow-up period varying from 2 to 39 months. Synovitis was suspected by arthroscopy in 67% and verified histologically in 52%, although in a milder form than at the time of synovectomy. The regenerated synovial tissue was less permeable to serum proteins and contained lower activities of lysosomal enzymes than the excised synovial tissue. Although the number of leucocytes decreased in the joint fluid after synovectomy, the activities of lysosomal enzymes were lowered only slightly, and there was no change in the amount of C3 and C4 components of complement pathway.