Spinal arthritis has long been recognized as a cause of discomfort, disability and deformity. The old text-book picture is quite familiar, and these extreme cases are encountered just often enough to give the impression that arthritis of the spine is rather rare. Modern roentgen technic has made it convenient to study spines more closely, leading to a surprising revelation of the frequency of spinal disease, especially in relation to industrial disabilities involving the spine. During the past few years, while I was endeavoring to diagnose and rate obstinate cases of spinal disease and their vexing symptom complexes, in which the disability seems entirely out of proportion to the injury, spinal arthritis entered so frequently into the diagnosis that I feared I was developing a hobby complex. A search of textbooks and of the literature brought to light valuable information regarding its etiology, pathology, diagnosis and treatment but did not give