骨量改变对特发性侧凸脊柱的影响机制  

Effects and mechanism of bone mineral mass changes in adolescent idiopathic scoliosis

作　　者：李新锋[1] 宋超[1] 刘祖德[1] 

机构地区：[1]上海交通大学医学院附属仁济医院骨科,200127

出　　处：《中华小儿外科杂志》2013年第10期757-760,共4页Chinese Journal of Pediatric Surgery

基　　金：上海交通大学医工（理）交叉研究基金（YG2012MS25）;上海交通大学医学院科技基金项目（2008xJ016）

摘　　要：目的研究轴向负载条件下，骨量改变对特发性脊柱侧凸不同脊柱结构的力学影响。方法基于特发性脊柱侧凸患儿CT扫描数据，构建骨量正常和骨量减少两种三维有限元模型，进入软件前处理器，设置边界条件和载荷，进入求解模块，进行轴向负载模拟计算，最后进入软件后处理器，读取并分析不同骨量情况下，脊柱侧凸不同部位和结构内生物力学响应特征。结果骨量改变会影响侧凸脊柱的力学响应。骨量减少后，胸主弯凹侧椎体皮质骨应力增加约155MPa，侧凸顶椎区域椎间盘应力平均增加8．46MPa，而L/4-5；和L5～S1椎间盘分别轻度降低约1．23MPa和0．04MPa，胸椎和腰椎终板内应力分别增加116．58MPa和10．54MPa，位于胸主弯凹侧和凸侧的胸椎和腰椎终板间的应力差增大，腰椎关节突关节内应力增加。结论特发性脊柱侧凸患儿合并骨量减少后，长期的非对称性载荷会造成胸主弯部位的椎体和椎间盘组织更为严重的楔形改变，凹侧终板可能会有更为严重的生长抑制。力学模拟提示，低骨量会加重特发性脊柱侧凸患儿的畸形进展和造成更为严重的腰椎代偿性畸形改变。Objective To investigate the influence of the bone mineral status changes on the biomechanical responses in adolescent idiopathic scoliosis （AIS） under axial load condition. Methods Three dimensional finite element models of adolescent idiopathic scoliosis with normal and bone mineral loss were built based on the data of computer tomography. The model was imported into the preprocessor of the model software for assigning boundary and loading conditions. Then the axial loading condition was simulated after entering the solution modular. The biomechanical response of the different parts and structures of the scoliotic spine were read and analyzed in the postprocessor of the model software. Results Bone mineral loss changed the mechanical response of scoliotic spine. With bone mineral loss, the stress increased 155 MPa in cortical bone of the concave side of the thoracic structure curves, the disc at the apex of the scoliosis experienced 8. 46 MPa stress increasing, whereas IA-5 and L5-S1 disc had mild stress decrease of i. 23 MPa and 0. 04 MPa, the stress of 116. 58 MPa or 10. 54 MPa increase in either thoracic or lumbar endplate were shown respectively; the stress difference in endplate between the concave and the convex side of the thoracic structure curve and the lumbar curve was increased and the stress in lumbar facet joints was also increased. Conclusions In low bone mineral status, long term of high asymmetrical stress could result in more serious wedging of the vertebrae and disc at the thoracic structure concave curve,and probably more serious endochondral longitudinal growth inhibition happens in the endplate at the concave major curve side. Biomechanical simulation indicates that low bone mineral mass could aggravate curve progression and induce more serious lumbar compensatory scoliosis in AIS patients.

关 键 词：脊柱侧凸 有限元分析 生物力学 

分 类 号：R726.8[医药卫生—儿科]