Content and composition of glycosaminoglycans in human knee joint cartilage. Variation with site and age in adults.

The content and composition of the matrix of human articular cartilage from two sites - the condylar summits and the upper, posterior surfaces of both lateral and medial sides - of the lower femoral epiphysis of 12 autopsy cases (age 18-46 years) were analyzed. A significantly higher content of both chondroitin sulphate and especially of keratan sulphate was found in cartilage of the condylar summits. The solubility profile of keratan sulphate showed changes indicating a difference between the metabolism of cartilage of the two sites. No significant change with side (medial or lateral) was found. A small decrease in the chondroitin sulphate to keratan sulphate ratio without change in the total amount of hexosamines with age was found on the caudal condylar summits in these adult individuals below the age of 50.