不同腰椎生理曲度下牵引的三维有限元分析

文题释义：腰椎牵引：是指令患者平卧于治疗床上，使用束带将患者前臂固定，达到医者固定患者双臂的目的；波浪式滚动气柱以腰背部为作用点进行顶推，控制多层气柱叠加高度使受试者腰部逐渐过伸牵引脊柱关节，实现对软组织的牵伸，并结合自身重力过伸牵引脊柱关节，能够增大椎间隙及调整椎小关节，最终达到理筋整复的作用。 三维有限元分析：是指在获取腰椎的CT图像数据，并导入到Mimics等软件当中建立的有限元模型基础上，将L₃的发生的位移变化带入MSC.Nastam软件中，高度仿真模拟人体在不同生理曲度下，计算分析出全腰椎各节段椎体、椎间关节、椎间盘、前纵韧带的应力值及分布情况的变化。 背景：近年来利用有限元分析方法研究腰椎生物力学成为热点，研究认为腰椎生理性前凸可减少腰椎间盘压力负荷，而对腰椎起保护效应。 目的：研究腰椎在正常生理曲度、屈曲位及最大过伸位下进行腰椎牵引时对L₁-L₅腰椎各节段的生物力学效应，并评估腰椎牵引的最佳生理曲度。 方法：选取1名健康男性志愿者，26岁，身高174 cm，体质量60 kg，既往体健，排除腰椎骨骼异常疾病。以受试者L₃为作用点徒手操作南少林倒盖金被法，利用DR机分别获得受试者腰椎起始位和最大过伸位的腰椎侧位片，构建全腰椎有限元模型。计算腰椎不同生理曲度下全腰椎各节段椎体、椎间关节、椎间盘、前纵韧带的应力值及分布情况的变化。研究方案的实施符合福建中医药大学附属康复医院相关伦理要求，受试者对试验过程完全知情同意。 结果与结论：①模拟腰椎前屈、后伸，左右侧弯，左右旋转6种工况活动度：L₁-L₂的前屈与后伸活动度之和为9.31°，左右侧弯9.84°，左右旋转4.43°；L₂-L₃：前屈与后伸10.22°，左右侧弯12.35°，左右旋转4.57°；L₃-L₄的前屈与后伸的活动度之和为11.20°，左右侧弯11.63°，左右旋转5.32°；L₄-L₅前屈与后伸活动度之和13.16°，左右侧弯11.58°，左右旋转5.05°；②在正常生理曲度牵引腰椎时，腰椎各个结构的应力值远大于过伸位牵引的应力值；前纵韧带应力值正常曲度是2.47 MPa，过伸位是21.20 MPa；L₃的椎体应力值达到最大，是过伸位牵引应力值的4倍；L₂-L₃的椎间关节及椎间盘的应力值在腰椎各个节段是最大的；③结果说明，腰椎在过伸位较正常生理曲度牵引下椎体、椎间关节、椎间盘的压力减轻更大，而且前纵韧带的压力值始终在安全范围内。腰椎在过伸位牵引时可能获得更好的临床疗效，同时具备一定的安全性。 ORCID: 0000-0002-4468-1464(李民) 中国组织工程研究杂志出版内容重点：组织构建；骨细胞；软骨细胞；细胞培养；成纤维细胞；血管内皮细胞；骨质疏松；组织工程

Three-dimensional finite element analysis of traction under different lumbar physiological curvatures

BACKGROUND:In recent years,the finite element analysis of lumbar biomechanics has become a hot topic.Lumbar lordosis is considered to reduce the pressure load on the lumbar intervertebral disc and protect the lumbar spine.OBJECTIVE:To study the biomechanical effects of lumbar traction on L1-L5 lumbar segments in normal physiological curvature,flexion position and maximum overextension position,and to evaluate the optimal physiological curvature of lumbar traction.METHODS:A healthy male volunteer,aged 26 years,with a height of 174 cm and a weight of 60 kg,was selected,who had no history of lumbar spine diseases.With the L3 segment as the traction site,a finite element model of the whole lumbar spine was established based on lateral radiographs of the lumbar spine at the initiation site and during the maximal overextension as photographed by a DR machine.Based on the three-dimensional finite element model of the lumbar spine,the stress values and distributions of the lumbar vertebrae,the intervertebral joints,the intervertebral discs and the anterior longitudinal ligaments of the whole lumbar spine under different physiological curvatures were calculated.The patient was fully informed of the study protocol and signed an informed consent.The study protocol was approved by the Ethics Committee of Rehabilitation Hospital Affiliated to Fujian University of Traditional Chinese Medicine.RESULTS AND CONCLUSION:(1)Under six kinds of simulated working conditions,the range of motion of L1-L2 was 9.31°for flexion and extension,9.84°for right and left bending,and 4.43°for right and left rotation;the range of motion of L2-L3 was 10.22°for flexion and extension,12.35°for left and right bending,and 4.57°for left and right rotation;the range of motion of L3-L4 was 11.20°for flexion and extension,11.63°for left and right bending,and 5.32°for left and right rotation;the range of motion of L4-L5 was 13.16°for flexion and extension,11.58°for left and right bending,and 5.05°for left and right rotation.Under the normal physiological curvature of the lumbar vertebrae,the stress value of different lumbar spine structures was much greater than the stress value of hyperextension traction.The normal curvature of the anterior longitudinal ligament was 2.47 MPa,and the curvature of hyperextension traction value was 21.20 MPa.The stress value of L3 was the highest,which was four times that of the hyperextension traction.The stress value of the intervertebral joints at L2-L3 and intervertebral disc was highest than that of any other segment of the lumbar spine.These findings indicate that the pressure of lumbar vertebrae,intervertebral joints and intervertebral discs in hyperextension position is less than that in normal physiological curvature traction,and the pressure of anterior longitudinal ligament is always within the safe range.Lumbar traction may have better clinical efficacy and definite security in hyperextension position.