Lesions of various organs resulting from interruption of the circulation are of common occurrence, and their pathologic and clinical aspects are generally known to the members of the medical profession. Examples are occlusions of the coronary, cerebral and pulmonary arteries and infarctions of the kidney and of the spleen. However, in the case of bones the same generalizations cannot be made. Although it has been accepted since the report of Langer1 in 1875 that the bones contain end arteries, knowledge of changes in bones and joints from vascular blockage was slow in developing. There are a number of reasons for this: first, the absence or mildness of immediate symptoms resulting from simple interruption of circulation in bone; second, postmortem examinations of the skeleton are much less common and less extensive than are those of the viscera; third, operation affording a chance for pathologic examination is seldom indicated with most