Organization of ground substance proteoglycans in normal and osteoarthritic knee cartilage

A study of the organization of proteoglycans in articular cartilage indicates that nonaggregated proteoglycans existed in larger numbers in osteoarthritic than in normal cartilage and that proteoglycan aggregates in arthritic cartilage were smaller than normal. After dissociation from hyaluronic acid and tissue glycoproteins, no difference in hydrodynamic size of disaggregated proteoglycans was noted, but chondroitin sulfate chains of those from diseased cartilage were shorter than normal. The data suggest that there is a defect in proteoglycan aggregation in osteoarthritic cartilage which could be of pathogenetic significance.