激素性股骨头坏死机制的实验研究

目的 探讨激素性股骨头坏死的发病机制。方法 激素对体外成骨细胞生长影响的细胞实验和激素性股骨头坏死的动物实验。结果 细胞培养显示，地塞米松抑制成骨细胞生长，使骨髓单个核4细胞向脂肪样细胞分化；动物实验显示，大剂量激素能造成股骨头坏死，表现为骨细胞死亡，骨髓内大量脂肪组织增生，软骨下区血管减少。结论 激素性股骨头坏死的发病机制可能是一方面激素直接抑制成骨细胞生长，造成成骨障碍；另一方面引起骨髓脂肪组织增生，髓腔内压增高，造成股骨头微循环紊乱，两者共同引起股骨头坏死。

An experimental study of hormone-induced necrosis of femoral head

Objective To study the mechanism of steroid induced necrosis of femoral head. Methods The cell experiment of effect of dexamethasone on the osteoblast in vitro and animal experiment of steroid induced necrosis of femoral head. Results The cell experiment showed that dexamethasone played two roles to bone marrow' mononucleate cells in vitro. The first was that it can prevent the cells from differentiating into the osteoblasts and the second was that it can cause fatty degeneration. The animal experiment showed the number of vacant bony lacunae in femoral head, the average diameter of fat cells in marrow cavity were increased and the number of blood vessles in subchondral areas was decreased with large doses of dexamethasone. Conclusions The mechanism of steroid induced necrosis of femoral head was that dexamethasone can inhibit the grouth of the osteoblasts directely, and cause fatty proliferation of bone marrow resulting in disorder of micro circulation and osteonecrosis in the femoral head.