Fig. 5.

Photographs of the mid-coronal plane of the resected femoral head and neck, and the whole mounted histologic specimen (A). Microscopically, the trabecular bone and marrow in the femoral head are extensively necrotic (asterisk, area surrounded by black dotted line) (B). Red line and black arrows indicate the fracture line. A histopathologic image of the necrotic region shows accumulation of bone marrow cell debris, along with bone trabeculae with empty lacunae beneath the fracture line (C). The reactive zone is composed of vascular granulation tissue (solid arrowhead) and trabeculae thickened by the formation of appositional new bone (black arrows). The dotted line indicates the fracture line; the open arrowheads indicate necrotic trabeculae (D).