应用自适应骨重建理论研究股骨头缺血性坏死囊变引起的骨密度改变

Study bone density changes in femoral head with avascular necrosis cystic degeneration using adaptive bone remodeling theory

目的探讨股骨头缺血性坏死囊变对骨密度分布的影响。方法采用Weinans-Huiskes骨重建模型,运用有限元分别计算正常股骨头及囊变股骨头骨密度分布。结果 (1)模拟生成了正常股骨上段内侧压缩小梁束M、横向张力小梁束L、粗隆间的斜向小梁束I和Ward三角。(2)如果发生一个原发囊变,则原发囊变区外下方会出现继发囊变区,且继发囊变区骨的密度将随原发囊变区体积的增大而急剧减小。囊变还将改变股骨的承重桁架系统。结论 (1)Wolff定律与现代拓扑优化理论是吻合的;(2)股骨头缺血坏死出现囊变后,应及时治疗以阻止继发新的囊变和股骨头塌陷的产生。

Objective To explore the effect of avascular necrosis cystic degeneration on distribution of bone den- sity. Methods Based on the bone reconstruction model of Weinans and Huiskes, bone density distribution in normal femoral head and in femoral head with avascular necrosis cystic degeneration were calculated by finite ele- ment analysis. Results （ 1 ） The medial system of lameUae, lateral system of lameUae, intertrochanteric arch and Wards triangle were generated on the normal proximal femur under simulation. （2） If a primary cystic degen- eration occurred, a secondary cystic area would appear below the primary one and its bone density would de- crease dramatically with the primary cystic area increased. Cystic degeneration would also change the femoral bearing truss system. Conclusions （ 1 ） Wolff＇ s law on bone remodeling is consistent with modern topology op- timization theory. （2） If cystic degeneration appeared due to avascular necrosis of the femoral head, it should be treated timely to prevent the secondary cystic degeneration and collapse of the femoral head.