目的:探讨髋关节内侧间隙比值(the medial space ratio，MSR)和臀中肌状态对股骨头坏死(osteonecrosis of the femoral head，ONFH)塌陷的影响。方法:基于3名健康志愿者的髋部CT数据，建立7种不同MSR(14。35、16。35、18。35、20。35、22。35、24。35、26。35)的左侧ONFH有限元模型。基于其中1名健康志愿者的正常MSR的ONFH有限元模型，构建7种不同臀中肌状态的ONFH有限元模型(75％、80％、85％、90％、95％、100％、105％)，其中100％臀中肌状态对应臀中肌肌力为700 N。所有模型均基于日本骨坏死调查委员会分型C1型建模，并将股骨头前侧保留角和外侧保留角均设置为70°，同时将坏死区体积定义为股骨头体积的30％。模拟双下肢静立状态下模型的受力情况，测定不同MSR的ONFH有限元模型的股骨头最大应力、坏死区最大应力及坏死区最大位移，测定不同臀中肌状态的ONFH有限元模型的股骨头最大应力、坏死区最大应力及股骨头向外侧位移。结果:①模型验证结果。本研究建立的ONFH有限元模型的主要负重区为股骨头前、外侧区域，应力集中现象出现在坏死区上方与受力区重叠部位，股骨头最大应力为(5。050±0。377)MPa，与既往研究报道的坏死股骨头应力传导特征基本一致。②不同MSR的ONFH有限元模型应力和位移测定结果。当MSR≤20。35时(即MSR为14。35、16。35、18。35、20。35)，模型的股骨头最大应力、坏死区最大应力、坏死区最大位移的组间差异均无统计学意义。当MSR＞20。35时(即MSR为22。35、24。35、26。35)，模型的股骨头最大应力、坏死区最大应力、坏死区最大位移均高于MSR≤20。35的模型。③不同臀中肌状态的ONFH有限元模型应力和股骨头向外侧位移测定结果。在正常MSR的ONFH有限元模型中，随着臀中肌状态好转，股骨头最大应力、坏死区最大应力、股骨头向外侧位移随之不断减小。结论:MSR＞20。35时，股骨头和坏死区应力明显增大，塌陷风险增高;良好的臀中肌状态不仅能降低股骨头和坏死区应力，而且能对抗股骨头外移，降低股骨头塌陷风险。
Effects of hip joint medial space ratio and gluteus medius status on collapse in osteonecrosis of the femoral head:a finite element analysis-based biomechanical study
Objective:To explore the effects of hip joint medial space ratio(MSR)and gluteus medius(GM)status on collapse in osteo-necrosis of the femoral head(ONFH).Methods:Three healthy volunteers were selected,and the CT data of their hips were extracted,based on which the finite element models of left ONFH with different MSRs(14.35,16.35,18.35,20.35,22.35,24.35 and 26.35)were estab-lished.Furthermore,based on the finite element model of ONFH with a normal MSR in one of the healthy volunteers,the finite element mod-els of ONFH with different GM statuses(75％,80％,85％,90％,95％,100％,and 105％)were built,among which the 100％GM status corresponded to a GM force of 700 N.The models were constructed according to the Japanese Investigation Committee(JIC)classification for ONFH(type C1),with the anterior and lateral preserved angles of the femoral head set to 70 degrees,and the volume of the necrotic zone defined as 30％of the total volume of the femoral head.The load-bearing situation of the model in the static standing state of lower limbs was simulated to measure the maximum stress of the femoral head,the maximum stress of the necrotic zone,and the maximum displacement of the necrotic zone of the ONFH finite element models with different MSRs,as well as the maximum stress of the femoral head,the maxi-mum stress of the necrotic zone,and the lateral displacement of the femoral head of the ONFH finite element models with different GM sta-tuses.Results:①The model verification results.The main load-bearing zones of the ONFH finite element models established in this study presented in the anterior and lateral regions of the femoral head.The stress concentrated in the overlapping area of the necrotic zone with the load-bearing zone,with the maximum stress as 5.050±0.377 MPa in the femoral head,which was basically consistent with the stress con-duction characteristics of the necrotic femoral heads reported in previous studies.②The stress and displacement of ONFH finite element models with different MSRs.In the case of MSR ≤20.35(i.e.,MSR was 14.35,16.35,18.35,and 20.35,respectively),the difference was not statistically significant among the groups in the maximum stress of the femoral head,the maximum stress of the necrotic zone,and the maximum displacement of the necrotic zone,while,in the case of MSR＞20.35(i.e.,MSR was 22.35,24.35,and 26.35,respectively),the maximum stress of the femoral head,the maximum stress of the necrotic zone,and the maximum displacement of the necrotic zone in the models were all greater than those in the models with MS ≤20.35.③The stress and lateral displacement of the femoral head in ONFH finite element models with different GM statuses.In the finite element model of ONFH with a normal MSR,the maximum stress of the femoral head,the maximum stress of the necrotic zone,and the lateral displacement of the femoral head kept decreasing as the GM status improved.Conclusion:In the case of MSR＞20.35,the stresses of the femoral head and necrotic zone significantly enhanced,which increased the risk of collapse.A good status in GM can not only reduce the stresses of the femoral head and necrotic zone but also counteract the lateral dis-placement of the femoral head,thereby reducing the risk of collapse in the femoral head.
femur head necrosiship joint medial space ratiogluteus medius musclefinite element analysisbiomechanical phenomena
万方数据
维普
