髋关节表面置换术假体柄固定方式对股骨近端骨密度及应力影响  

Effect of stem fixing methods on stress and bone mineral density in the proximal femur following hip resurfacing arthroplasty

作　　者：屈瑾[1] 雷新玮[1] 展影[1] 张晨[1] 姜文学[2] 祁吉[1] 

机构地区：[1]天津市第一中心医院放射科,300192 [2]天津市第一中心医院骨科,300192

出　　处：《中华医学杂志》2014年第35期2769-2771,共3页National Medical Journal of China

基　　金：天津市卫生局科技基金（2011KY06）

摘　　要：目的 应用有限元分析方法研究髋关节表面置换术（RSAH）股骨侧假体柄周围骨水泥厚度与股骨近端应力分布间关系,比较术后手术侧与健侧股骨近端骨密度差异.方法 选择天津市第一中心医院2008年6月至2012年6月单侧行RSAH患者于术后6个月行双侧髋关节骨密度检查,股骨近端参照Taylor方法分为5区,比较两侧各区骨密度差异.建立股骨侧假体柄周围骨水泥厚度不同的RSAH术后及正常股骨近端三维有限元模型,分析股骨近端各区应力分布及应力遮挡情况.结果 骨水泥厚度1 mm时两侧1、2、3区骨密度差异均无统计学意义（均P＞0.05）,4、5区手术侧骨密度分别为健侧的121.59％及112.90％,差异有统计学意义（P ＜0.05）;RSAH有限元分析提示骨水泥厚度为0和1 mm时股骨近段各区应力遮挡率均小于骨吸收阈值（17％）,1 mm时2、5区应力遮挡率较0 mm时略增加;骨水泥厚度为2及3 mm时各区应力遮挡率增加,部分超过17％.结论 薄层骨水泥固定时股骨近端应力遮挡率较小,股骨近端骨量可以得到有效保存和恢复.Objective To construct different 3-D finite element resurfacing arthroplasty of hip models and to explore the biomechanics influences of cement mantle varying in thickness on stress distribution and stressshielding in the proximal femur following hip resurfacing arthroplasty （RSAH）,and evaluate the changes of bone mineral density in femur after RSAH,in order to find the adaptive methods to stem fixing.Methods A comparative study was carrie out in patients who underwent RSAH.The bone mineral Density of the proximal femur was measured through dual energy X-ray absorptiomenty of the four zone at post-operation and unoperation 6 months.Changes of bone mineral density ratio in proximal femur between post-operation and unoperation were compared and analyzed.the finite element models of RSAH with different thickness of cement mantle and normal femur were developed and stress analysis was performed under the load of body weight.Results The mean ration of bone mineral density of proximal femur in zone1,2,3 increased which was no significantly different from other areas （P 〉 0.05）,the mean ration of bone mineral density of proximal femur in zone 4 and 5 increased which was significantly different from other areas （P 〈 0.05）.Comparing with the 0 mm cement mantle model,the ratio of stress shielding of the cancellous bone around the stem in 1 mm cement mantle model has slightly increased,but also was less than 17%.The ratio of stress shielding was increased obviously in the 2 and 3 mm cement mantle mode and more than 17% in 1,2 and 5 zone.Conclusion The cement around stem not thicker than 1 mm produced slightly effect to the stress decreasing and did not result in marked stress shielding in the proximal femur following RSAH,and the bone stock of proximal femur can be well perserves and recovered.

关 键 词：关节成形术 置换 髋 有限元分析 生物力学 骨密度 

分 类 号：R687.4[医药卫生—骨科学]