The collagen, mucopolysaccharides, sulphur, non-protein nitrogen, and non-collagenous protein content were determined in the articular cartilage of joints of the lower extremity its sixty patients. The results were analyzed with relation to the ages of the patients, the sites from which the cartilage was taken, and the extent of focal degenerative joint disease.

For the entire group of patients, whose ages ranged from ten to ninety years, the average values were as follows: collagen, 56.4 per cent; mucopolysaccharides, 20.3 per cent; and non-collagenous protein, 22.8 per cent. A wide range of values for all components was found in all groups regardless of age, diagnosis, or origin of cartilage. For example, both the highest (81 per cent) and the lowest (43 per cent) values for collagen were found in the group with severe degenerative joint disease. Marked, although less extreme, variations were found in specimens from normal articular cartilage and in those with mild degenerative changes. Such wide variations made satistically valid comparisons virtually impossible.

In general, it may be stated that there is no significant variation in the values for organic matrix components between normal articular cartilage and the cartilage surrounding the lesions of degenerative joint disease.

There were no significant variations related to the articular surface (hip, knee, ankle, or tarsus) from which the cartilage was obtained. The only significant variations were related to the age of the patient.

Significant variations in histochemical staining reactions were observed only in the areas of actual cartilage fibrillation and erosion.

These findings tend to confirm the currently popular belief that degenerative joint disease is a focal process, probably related to mechanical stresses, and not to a generalized matrix deficiency in the joint surface involved, although differences may occur it the type of mucopolysaccharides in joints undergoing degenerative changes.