The Roentgen era has added much to our knowledge of joint pathology and has made possible a broader classification and a more comprehensive therapy of joint disease.
In the production of joint disease trauma undoubtedly plays a most important rôle. The trauma may result in a gross lesion of the joint, it may be the determining factor in the localization and growth in the joint structures of micro-organisms already present in the blood or lymph stream, or the trauma may initiate degenerative or chronic inflammatory changes in the synovial elements, changes which may in time impair or destroy the integrity of the joint. It is to this latter class of cases that attention is directed.
The histologic elements making up a joint are of comparatively low organization and scant vascularity. Degenerative and chronic inflammatory changes of a fibroid or calcareous nature are, therefore, very prone to occur in the joint