Experimental arthrosis. Early changes in synovial morphology and lysosomal enzyme activities.

The Hulth procedure was used to induce osteoarthrosis in a knee-joint in 36 rabbits, whereupon changes in chondral and synovial morphology and lysosomal enzyme activities were studied over a period of 3 months. A significant increase in enzyme activities was observed, which was more pronounced and seemed to occur earlier in the synovial membrane than in the cartilage. The synovial morphological changes were conspicuous in an early stage of the disease process and also seemed to precede the changes in chondral morphology. The results of this study suggest an important role of the synovial membrane in the pathogenesis of osteoarthrosis.