It is customary nowadays to open any discussion on the treatment of chronic arthritis with a preliminary paragraph on the classification of the disease. This is a rational procedure, but unfortunately the terminology now in use is confusing to many physicians, chiefly because of the multiplicity of synonyms. Many of these synonyms might well be forgotten. As a matter of fact the modern classification of chronic arthritis is quite simple, much simpler than that of chronic nephritis or chronic heart disease. The differentiation of chronic arthritis into two groups has resulted largely from careful pathologic studies of the disease, but there are definite clinical features of each type as well.
Pathologically the two great groups are so different that it is hard to see how any one could confuse them. Osteo-arthritis, or hypertrophic arthritis, is well named, because it is a degenerative process which affects the bone and cartilage. The