An adequate blood supply is necessary for the nutrition of bone tissue. Complete interruption of the circulation causes infarction or aseptic necrosis.1 The extent of such a circulatory disturbance determines the amount of necrosis in a bone, although impeded or interrupted circulation does not affect equally all bone tissue. According to Haslhofer,1 Axhausen and Bergmann1 and Müller,2 diminished blood supply causes necrosis of portions of the bone tissue while the marrow structures remain intact. The statements of these authors emphasized that bone as a tissue is readily damaged by obstruction of the circulation, a view in marked contrast with the older opinion that the great vascularity of bones precludes infarction. Burckhardt3 shared this view and concluded that excessive stress of the bands carrying the nutrient vessels to bones or a direct break in the continuity of the nutrient blood supply would cause a serious local