Ankylosis of the elbow is probably more objectionable than ankylosis in any other joint in the body. Elsewhere, while stiffness is objectionable, there is, nevertheless, an advantage gained in obtaining stiffness in a good position, more particularly in the hip and knee joints. In the hip, for example, we try to get extension and abduction, realizing that flexion and adduction are deformities interfering with function. In these joints, the endresults of arthroplasties are not so certain. In the elbow, however, there is no position in which ankylosis will not interfere with function. Ankylosis is in the main the result either of infection or of trauma. The former may be caused by various organisms. When the onset is sudden and the course severe, the causative agent is usually the pneumococcus, gonococcus or streptococcus. Ankylosis may, however, result from a polyarticular arthritis, of insidious onset and progressive course. In the former, the