Pathological study of avascular necrosis of the femoral head in spontaneously hypertensive rat

本文对雄性自发性高血压大鼠（SHRs）股骨头病变进行了影像学和组织学研究。在SHRs生长的早期，即出生后6 - 15周，股骨比对照大鼠短，股骨头骨骺的骨化明显迟缓。SHRs股骨头坏死在9周时出现，骨骺和干骺端生长板软骨异常，随后出现软骨内成骨。此外，我们还利用连续切片研究了股骨头骨坏死血管闭塞的原因。供应股骨近端骨骺的外侧骨骺血管在进入股骨头之前立即消失。新鲜骨坏死时，关节软骨边缘与干骺端生长板之间的血管通路被肉芽组织或瘢痕组织取代。我们认为血管闭塞发生在骺软骨外侧血管穿透的层，骨坏死的发生可能与骺软骨和干骺生长板的异常有关。

The femoral head lesions of male spontaneously hypertensive rats (SHRs), which occur naturally and resemble Perthes disease in man, were investigated radiographically and histologically. In the early phase of growth in SHRs, i.e., a period of 6 to 15 weeks after birth, the femur was shorter than that of control rats, and ossification in the epiphysis of the femoral head was considerably retarded. Osteonecrosis of the femoral head of SHRs appeared at the age of 9 weeks, and an abnormality of the cartilage in the epiphysis and metaphyseal growth plate and subsequent enchondral ossification were seen frequently. Furthermore, the cause of the vascular occlusion in osteonecrosis of the femoral head was investigated using serial sections. The lateral epiphyseal vessels, which supply the proximal femoral epiphysis, disappeared immediately before entry into the femoral heads. In fresh osteonecrosis, the pathway of the vessels between the margin of the articular cartilage and metaphyseal growth plate was replaced with granulation or scar tissue.We conclude that the vascular occlusion occurs in the layer of the epiphyseal cartilage where the lateral epiphyseal vessels penetrate, and that the abnormalities of the epiphyseal cartilage and metaphyseal growth plate might play a part in the occurrence of osteonecrosis.