The knowledge of chronic rheumatism has reached a stage in which a satisfactory classification based on pathologic changes, etiology and clinical manifestations can be made. Two types, distinguishable clinically, have been accepted: (1) rheumatoid arthritis, infective in origin, and (2) osteo-arthrosis, a degenerative disease. Osteo-arthrosis of the spine is exceedingly common; in fact, no other articulations are so frequently involved. The reason for this will be considered later.
A much discussed question is: Does rheumatoid arthritis attack the spine? As this disease begins in the synovial membrane and later destroys the underlying cartilage, it is not probable that it would attack the intervertebral disks which do not have a synovial membrane. However, the vertebrae have articulations anatomically identical with those of the extremities, namely, the articulations of the ribs and transverse processes, commonly referred to as the small articulations of the spine.
Investigation of rheumatic diseases of the spine is