青少年特发性脊柱侧凸患者的椎体及椎间盘楔形变的影像学研究

目的 观察进展型青少年特发性脊柱侧凸支具治疗前及手术治疗前椎体和椎间盘楔形角的变化,并探讨椎体和椎间盘楔形变与侧凸之间的相关性.方法 对2001年6月至2003年8月间37例青少年特发性脊柱侧凸患者支具治疗前和手术治疗前影像学上椎体和椎问盘的楔形变及侧弯的角度进行测量,本组男6例,女31例,年龄11～18岁,平均14.9岁.根据PUMC分型:PUMC la 8例,PUMC I b 3例,PUMC I c 5例,PUMC Ⅱ bl 12例,PUMCⅡ b2 3例,PUMC Ⅱ cl 3例,PUMC Ⅱ e3 l例,PUMC Ⅱ dl 2例.结果 发育成熟(Risser征Ⅳ～V)及月经初潮2年以上的患儿支具治疗前后的椎体、椎问盘楔形角与侧凸Cobb角的相关程度较低(r=0.17),而发育不成熟的患儿(Risser征0～Ⅲ,月经未来潮)支具治疗前后的椎体、椎间盘楔形角与侧凸Cobb角的相关程度较高(r=O.69).随着侧凸的进展,椎体和椎间盘的楔形角明显增加,椎体和椎间盘的楔形变同侧凸的进展明显相关,并与侧凸的程度呈正相关.结论 在侧凸的发生和进展过程中椎体和椎间盘出现明显的楔形变,并随着侧凸的加重而变得更加明显,表明椎体软骨终板的不对称生长可能是导致椎体楔形变的关键因素.     

脊柱侧弯应用PRSS矫正过程中的力学性能研究

[目的]脊柱侧弯时椎体和椎间盘出现凹侧低、凸侧高的楔形变，造成两侧的不对称应力；而在应用PRSS侧推矫形后不对称应力相应减少。本实验用模型实验方法研究PRSS矫正脊柱侧弯过程中的力学行为。[方法]椎体模型选择铝材，椎间盘及韧带模型材料选择聚碳酸脂，建立5个椎体、4个椎间盘的脊柱模型并模拟轻度侧弯情况，分别取纵向载荷为0kg、5kg、10kg、15kg、20kg，横向载荷分别为0kg、3kg、6kg、9kg、12kg。按原型矫正过程的载荷，进行加载试验，利用光弹性法及应变电测法测量了模型应力。利用有限元ANSYS软件模拟并验证实验的可靠性。[结果]脊柱受矫正力后，脊柱处于纵向力和横向力的联合作用状态，界面法向应力分布明显改变，凸侧的法向压应力增加，凹侧的压应力降低并可转变为拉应力。拉应力值与矫正力成正比关系。在一定的矫正力作用下，模型凹侧压应力值逐渐减小，直至出现拉应力，而凸侧依然是压应力，并且应力值比施加矫正力前更大。[结论]脊柱侧弯应用PRSS矫正过程中，随着矫正力的增加，凸侧的压应力增大，同时凹侧的压应力迅速减小并可产生拉应力。这样可促进凹侧骨的生长，抑制凸侧骨的生长，使脊柱生长变直，从而达到矫正脊柱侧弯的目的。     

青少年特发性脊柱侧凸支具治疗研究分析

[目的]探讨胸腰骶支具治疗青少年特发性脊柱侧凸的临床疗效,为开展青少年特发性脊柱侧凸的筛查和临床治疗提供参考依据。[方法]对2004年10月~2012年2月在云南部分地区筛查中确诊为青少年特发性脊柱侧凸的132例患者进行Lenke分型,并予胸腰骶支具治疗,比较治疗前后Cobb角。[结果]Lenke1型治疗前后Cobb角平均减小9°,差异具有统计学意义(P0.05),Lenke3型治疗前后胸弯Cobb角平均减小5.2°,胸腰弯Cobb角平均减小6.4°,差异均具有统计学意义(P0.05),Lenke5型治疗前后Cobb角平均减小12.7°,差异具有统计学意义(P0.05),Lenke6型治疗前后胸弯Cobb角平均减小2.0°,胸腰弯Cobb角平均减小6.8°,差异没有统计学意义(P0.05)。[结论]12~16岁是青少年特发性脊柱侧凸重点普查对象,胸腰骶支具对减缓或阻止Lenke1型、Lenke3型和Lenke5型畸形具有显著作用,而对Lenke6型没有明显效果,支具治疗对阻止或减缓病情发展不受年龄、性别和分型的影响。     

青少年特发性脊柱侧凸与神经源性脊柱侧凸患者椎体和椎间盘的楔形变及其临床意义

目的:观察青少年特发性脊柱侧凸(adolescent idiopathic scoliosis,AIS)与神经源性脊柱侧凸(neurological scoliosis,NS)患者的椎体和椎间盘的楔形变情况,探讨其临床意义。方法:对35例AIS患者和31例NS患者(继发于Chiari畸形)应用Cobb法测量胸椎和腰椎每个侧凸范围内顶椎及其上、下各两个椎体和相应椎间盘的楔变角,计算其占整个侧凸角度的百分比(楔变率),得出侧凸范围内5个椎体的平均楔变率和4个椎间盘的平均楔变率。应用SPSS10.0统计软件进行统计分析,组间比较采用单因素方差分析。结果:相同病因、相同侧凸部位、相同Cobb角分组情况下,椎体与椎间盘的楔变率存在显著性差异(P0.05)。相同病因、相同侧凸部位,Cobb角60°组的椎体楔变率和椎间盘楔变率与Cobb角≥60°组比较均无显著性差异(P0.05)。相同侧凸部位、相同Cobb角分组,AIS组椎体和椎间盘的楔变率分别与NS组比较均无显著性差异(P0.05)。结论:AIS与NS患者椎体与椎间盘的相对楔形变方式相同,AIS患者的椎体楔形变可能是继发的。在治疗脊柱侧凸时,即便是较小角度的脊柱侧凸,都应该考虑到其存在椎体和椎间盘的楔形变。     

采用关键椎置钉及选择性融合治疗Lenke6型AIS可行性的有限元分析

[目的]通过有限元模型矫形手术模拟的方法探讨关键椎置钉技术的可行性及矫形效果,分析Lenke 6型脊柱侧凸是否适合采用选择性融合策略.[方法]通过CT图像建立1例Lenke 6型特发性脊柱侧凸三维有限元模型,并验证其有效性后,利用后路CD矫形手术模拟技术,分别模拟全节段椎弓根钉技术矫形工况、关键椎置钉技术矫形工况、胸腰弯选择性融合工况等.测量各种工况完成后双弯Cobb角度、计算矫形率,分析各种工况的矫形效果.[结果]全节段椎弓根钉技术(非选择性融合):胸腰弯矫形率47.8％,主胸弯矫形率43.9％;关键椎置钉技术:胸腰弯矫形率44.2％,主胸弯矫形率19.1％;胸腰弯选择性融合:胸腰弯矫形率43.5％,主胸弯矫形率14.3％.[结论]全节段椎弓根钉技术因矫形力施加点更多,矫形效果较关键椎置钉技术更佳;Lenke 6型脊柱侧凸采用选择性融合策略应慎重,非选择性融合策略能明显矫正双弯,纠正脊柱序列,更适合该类型病例.     

青少年特发性脊柱侧凸支具治疗结束后近期矫正丢失及影响因素

目的:观察青少年特发性脊柱侧凸(adolescent idiopathic scoliosis,AIS)支具治疗结束后短期内侧凸的矫正丢失情况,并探讨其影响因素。方法:选取2002年10月～2007年12月在我院完成规范化支具治疗后短期随访的AIS患者84例,其中男4例,女80例。初诊时年龄10～15岁,平均12.8岁;Risser征0～3级,平均1.6级;主弯Cobb角20°～43°,平均29.5°。胸腰双主弯36例,单胸弯22例,单胸腰弯或腰弯26例。所有患者在初诊、复查时均摄佩带支具前后站立位全脊柱正位X线片。分别测定不同时期侧凸Cobb角,记录侧凸类型、Risser征、患者的生理年龄及月经初潮时间,分析去除支具后侧凸的矫正丢失情况及影响因素。结果:AIS患者支具治疗后主弯Cobb角的平均矫正率为12.4%,其中14例(16.7%)患者在治疗期间出现脊柱侧凸进展,不同弯型脊柱侧凸的侧凸矫正率、进展率比较差异无显著性(P0.05)。支具治疗结束时主弯Cobb角10°～37°,平均25.5°,明显小于初诊时的29.5°(P0.05),停用支具后6～18个月主弯Cobb角为27.2°,与支具治疗结束时比较无显著性差异(P0.05)。停用支具后,有15例(17.6%)患者出现脊柱侧凸进展,不同弯型脊柱侧凸进展差异无统计学意义(P0.05);侧凸进展的患者在支具治疗时主弯Cobb角的平均矫正率为23.3%,明显高于未出现侧凸进展患者的10.6%,且差异具有统计学意义(P0.05)。停用支具时不同Cobb角组后期出现侧凸进展的概率无显著性差异(P0.05)。结论:支具治疗能够有效控制AIS患者侧凸的进展。在结束支具治疗后短期内随访侧凸矫正基本稳定,但仍有一小部分患者会出现侧凸进展,这种进展与弯型、侧凸的严重程度无关,可能与支具治疗期间侧凸的矫正率较大有关。     

胸椎楔形截骨术矫正胸段侧凸畸形

目的　探讨胸椎体楔形截骨在顶椎位于胸段脊柱侧凸矫形中的应用价值。方法　采用后路凸侧椎体楔形截骨、凹侧软组织松解、椎弓根系统内固定治疗胸段脊柱侧凸 2 3例 ,其中特发性脊柱侧凸畸形 2 0例 ,侧方半椎体畸形3例。共行截骨 2 9个椎体 ,T10 以上椎体截骨 14个 ,最高为T5椎体 ,T10 以下椎体截骨 15个。所有病例皆采用椎体冠状面楔形截骨。结果　术后随访平均 19.2个月 (4个月～ 36个月 )。术前Cobb角为 6 5°～ 110° ,平均为 74 .4°。术后测量的Cobb角为 10°～ 35° ,平均矫正率为 76 .5 % ;术后平均身高增长 4 .5cm。手术中失血为 80 0～ 82 0 0ml,平均170 0ml。术后皆无神经系统及其他方面的并发症。结论　单一后路椎体楔形截骨可有效矫正胸段脊柱侧凸     

单纯后路半椎体切除楔形截骨治疗先天性脊柱侧凸

目的 探讨单纯后路半椎体切除楔形截骨治疗先天性脊柱侧凸的治疗效果.方法 回顾性研究采用后路半椎体切除楔形截骨治疗先天性脊柱侧凸11例,对于重度僵硬的病例结合后路广泛松解.依据患者的影像学资料,并发症的发生情况等评估临床效果.结果 脊柱侧凸的主弯平均Cobb角为74°(62°～95°),术后矫正率为60%(48%～73%).后凸平均Cobb角为52°(40°～72°),术后矫正率为51%(41%～69%),手术前的冠状面失衡约19mm,术后为8mm,手术无任何严重并发症发生.结论 单纯后路半椎体切除楔形截骨治疗先天性脊柱侧凸疗效满意,对于重度僵硬的病例后路广泛松解效果较好.     

脊柱侧凸若干治疗问题的研究进展

1脊柱侧凸的椎体特征性楔形变对于制定矫形手术的计划来说,椎体楔形变是很重要的,比如对椎体截骨和对生长能力的评估。Stefan等在2004年第20期《Spine》上发表文章,对30具脊柱侧凸解剖标本椎体形变的量化分析:运用三维数字测量技术对椎体进行三维重建,对30具不同侧凸度数的标本进行测量,然后与正常标本相对照,包括胸椎和腰椎,作好记录进行差异分析和t检验,设定P=0.05。结果总共测量了471个侧凸椎体标本和510个正常椎体标本。椎体的楔形变随着接近顶椎而不断增加,其中最大的形变位于顶椎处。楔形变在冠状面较在矢状面明显。特别在上胸弯T3…     

青少年先天性半椎体脊柱侧凸畸形的手术治疗

[目的]探讨治疗青少年先天性半椎体脊柱侧凸畸形的手术方法及治疗效果。[方法]对18例青少午先天性半椎体脊柱侧凸患者,按照术式分为侧前路矫正、前后路联合矫正。首先通过胸腰段、腰段脊柱侧凸的半椎体、椎间盘切除,然后采用侧前路短节段椎体螺钉固定,旋转棒的三维旋转矫正脊柱的畸形7例;采用前后路联合入路,经后路行残余半椎体的关节突、椎板切除,凸侧加压、凹侧支撑固定11例。[结果]18例患者中侧凸平均矫正Cobb's角36.7°,矫正率77%,经18~28个月随访,达到满意的矫形效果,丢失率低,融合良好。[结论]小儿半椎体畸形应早期手术治疗。侧前路和前、后路联合半椎体切除临床效果满意,其中前路矫正手术用于胸腰椎、腰椎单一半椎体畸形。     

脊柱侧凸顶椎区椎间盘纤维环中多聚蛋白多糖的表达及意义

目的：探讨脊柱侧凸患者顶椎区椎间盘纤维环中多聚蛋白多糖的表达及其意义。方法：采集2003年7月至2004年9月间行前路松解或矫形手术的40例脊柱侧凸患者侧凸顶椎区椎间盘组织。青少年特发性脊柱侧凸患者（adolescent idiopathic scoliosis，AIS）25例，胸椎椎间盘11例，腰椎椎间盘14例；先天性脊柱侧凸患者（congenital scoliosis，CS）15例，胸椎椎间盘6例，腰椎椎间盘9例。利用RT—PCR扩增多聚蛋白多糖（Aguecan），琼脂糖凝胶电泳，在UVP（紫外光测定法）成像系统进行扫描．GelWork图像分析系统中进行灰度测定半定量分析。分别计算AIS组和CS组凹侧、凸侧纤维环中Aggrecan含量，并对CS组和AIS组胸椎和腰椎以及椎间盘的凹侧和凸侧进行比较。结果：AIS组和CS组椎间盘凹侧纤维环中Aggrecan含量低于凸侧．差异有显著性（P〈0．01），胸椎椎间盘纤维环中Aggrecan的含量低于腰椎，但无统计学差异。AIS组Aggrecan的含量和CS组相应部位Aggrecan的含量无明显差别。结论：AIS椎间盘纤维环凹凸侧存在Aggrecan代谢差异．并且可能是脊柱侧凸所致的继发改变．但也可能是脊柱侧凸发生、发展中的重要因素。     

退变性腰椎侧凸形成和发展的相关因素分析

目的 探讨退变性腰椎侧凸患者椎问盘的不对称指数、腰椎间盘退变程度以及骨密度降低对侧凸角度的影响.方法 采用回顾性研究的方法,选取2002年1月至2010年8月,共96例退变性腰椎侧凸患者为研究对象(侧凸组);2002年1月至2010年8月确诊为腰椎管狭窄症并且资料齐全的患者96例为对照组;两组间性别、年龄、体质量指数匹配.侧凸组:在腰椎正位X线片上测量凸凹侧顶椎间盘及其上下椎间盘的高度和顶椎及其上下椎体的高度,利用Adobe Photoshop 6.0软件,测量MRI图像T2WI顶椎及其上下椎间盘内髓核与脑脊液的相对信号强度.对照组:取2～3、L3-4、L4-5这3个椎间盘为研究对象测定上述指标.应用双能X线吸收法测定两组患者腰椎(L2-4)及股骨颈、股骨粗隆和Ward's三角的T值.结果 侧凸组凸侧椎间盘高度和为(40±7)mm高于凹侧的(28±7)mm(P<0.01),凸侧椎体高度和为(76±12)mm高于凹侧的(72±10)mm(P=0.016):两组之间的椎间盘退变程度差异有统计学差异(P=0.003);两组之间骨密度T值的平均值和骨质疏松的发生率差异有统计学意义(均P<0.01).通过多元线性回归分析结果 显示患者椎间盘的不对称指数、椎间盘的退变程度、骨密度T值影响退变性腰椎侧凸角度.结论 退变性腰椎侧凸常伴有凸凹两侧椎间盘高度以及椎体高度不对称.侧凸角度与椎间盘的不对称指数、椎间盘的退变程度呈正相关,与骨密度值T值呈负相关.

Abstract：

Objectives To investigate the correlation between scoliosis angle and the asymmetric index of degenerative lumbar scoliosis, the degree of intervertebral disc degeneration, decreased bone density. Methods As a retrospectively study, a total of 96 patients with degenerative lumbar scoliosis were retrospectively enrolled from January 2002 to August 2010 as scoliosis group, meanwhile % patients with lumbar spinal stenosis matched in gender, age and body mass index (BMI) were selected as control group.All patients were studied with plain radiographs, MRI and dual energy X-ray absorptiometry at presentation. Radiographic measurements include Cobb angle, the height of the convex and concave side of the apical disc and the contiguous disc superiorly and inferiorly, the height of the convex and concave side of the apical and the contiguous vertebral body superiorly and inferiorly in scoliosis group, the height of L2-3, L3-4, L4-5 discs and the height of L2-4 vertebral body in control group. The average relative signal intensity of lumbar intervertebral disc and cerebrospinal fluid in T2WI sagittal image was measured in apex intervertebral disc and adjacent discs by Adobe Photoshop 6.0 in scoliosis group, which was measured in L2-3, L3-4, L4-5 disc in control group. The bone density of lumbar, femoral neck, trochanter, and Ward's triangle regions were measured with dual-energy X-ray absorptiometry. Results The intervertebral disc height in convex side was greater than the height in the concave side [(40 ± 7) mm vs. (28 ± 7) mm, P < 0. 01] , the vertebral body height in convex side was greater than the height in the concave side [(76 ± 12) mm vs. (72 ± 10) mm, P =0.016] in scoliosis group. There was significant statistically difference in the degenerative degree of intervertebral discs between two groups (P = 0. 003). There was significant statistically difference of the average T-value and the rate of osteoporosis between two groups (P < 0. 01). Multiple linear regression analysis showed that the asymmetric disc index, the degenerative degree of intervertebral disc and osteoporosis were the predominant correlative factors, which affected the development of degenerative lumbar scoliosis. Conclusions Degenerative lumbar scoliosis is always accompanied by the height asymmetry of intervertebral discs and vertebral body from convex and concavity sides. There is positive correlation between the angle of scoliosis and the asymmetric disc index, the degeneration of intervertebral disc, and negative correlation between the angle of scoliosis and the bone density (T-value).     

Recovery from exercise-induced desaturation in the paraspinal muscles in idiopathic scoliosis.

STUDY DESIGN: A study using near-infrared light spectroscopy to measure recovery from exercise-induced desaturation in the paraspinal muscles of patients with idiopathic scoliosis. OBJECTIVES: To measure oxygenation of the paraspinal muscles and obtain differences between the convex and concave sides. SUMMARY OF BACKGROUND DATA: Authors of previous studies have reported that some patients experience pain on the convex side of the paraspinal muscles. The muscles on the convex side are more stretched and stressed than those on the concave side. The current authors investigated the degree of stress by measuring oxygenation and blood volume changes. METHODS: Paraspinal muscle spectral properties at L3 were investigated using near-infrared light spectroscopy. Thirty-six patients (8 men and 28 women) underwent this procedure. To assess a level of peripheral adaptations to exercise, the half-time of Oxyhemoglobin/Myoglobin recovery was measured, which indicates the recovery from energy deficit after exercise. RESULTS: The average half-time recovery on the convex side was 3.38 seconds (range, 1.5-5.5 seconds), whereas that on the concave side was 1.51 seconds (range, 0.7-4.0 seconds). The average difference between the convex side and the concave side was 1.87 seconds (range, 0.9-3.5 seconds). CONCLUSIONS: Half-time recovery on the convex side in the patients with idiopathic scoliosis was slower than that in healthy adults (P < 0.05). Half-time recovery on the concave side in such patients was faster than that on the convex side (P < 0.01). The authors consider half-time recovery an indication of back muscle stress.     

An experimental study on the pathology and role of intervertebral discs in the progression and correction of scoliotic deformity

This experimental study was designed to clarify the role of the intervertebral disc in the progression and correction of scoliosis. A total of 186 Wistar strain rats were used. Progressive scoliosis-like deformity was produced in tails by fixation of a given strain for a certain period. Changes in the intervertebral disc and epiphysis of one group with removal of the nucleus pulposus, and the other without removal were examined radiologically and pathohistologically. The results are as follows: 1) deformity originated from deviation of the nucleus pulposus toward the convex side and was followed by changes of the concave side, and led to deformities of the epiphysis and vertebral body; 2) on correction of the deformity, deviated nucleus pulposus and contracture of the concave side served as correction-inhibiting factors. The author's results indicate that intervertebral disc affecting the progression and correction of scoliosis are of great clinical significance.     

Ⅱ型胶原、转化生长因子β1和碱性成纤维细胞生长因子在脊柱侧凸患者关节突软骨中分布及表达的实验研究

目的研究青少年特发性脊柱侧凸（AIS）和先天性脊柱侧凸（CS）畸形最严重部位一顶椎凸、凹侧下关节突软骨中Ⅱ型胶原、转化生长因子β1（TGF—β1）和碱性成纤维细胞生长因子（bFGF）的表达特点。方法22例AIS患者,18例CS患者作为研究对象。取两组患者的顶椎和端椎凸、凹侧的下关节突,采用苏木素-伊红（HE）染色、免疫组化和原位杂交方法观察关节突的病理改变和Ⅱ型胶原、TGF-β1及bFGF在关节突中分布的特点。将所得的免疫组化和原位杂交图像输入图像分析系统,进行半定量分析,并作统计学分析。结果Ⅱ型胶原、TGF-β1、bFGF在AIS和CS中的有基本相似的表达特点,免疫组化和原位杂交方法均显示顶椎凹侧的表达高于凸侧,差异有统计学意义（P〈0．05）;上下端椎的凸凹侧之间及凸凹侧的上下端椎之间的表达差异无统计学意义,顶椎、上下端椎各对应部位在AIS与CS之间的表达差异无统计学意义;Ⅱ型胶原在凸侧与凹侧顶椎的表达高于同侧上、下端椎,差异有统计学意义（P〈0．05）。结论AIS和CS顶椎关节突软骨呈现退变及发育不全等征象,凹侧较凸侧明显。AIS和CS中Ⅱ型胶原、TGF—β1及bFGF在顶椎凹侧表达的增高可能为脊柱畸形后异常的生物力学引起了关节突细胞间基质重建而进行代偿的结果。压应力可引起TGF—β1及bFGF的表达增高;压应力和张应力均可以引起Ⅱ型胶原的表达增高,但顶椎凹侧压应力比凸侧张应力的影响更大。     

Rib cage surgery for the treatment of scoliosis: a biomechanical study of correction mechanisms.

Rib shortening or lengthening are surgical options that are used to address the cosmetic rib cage deformity in scoliosis, but can also alter the equilibrium of forces acting on the spine, thus possibly counteracting in a mechanical way the scoliotic process and correcting the spinal deformities. Although rib surgeries have been successful in animal models, they have not gained wide clinical acceptance for mechanical correction of scoliosis due to the lack of understanding of the complex mechanisms of action involved during and after the operation. The objective of this study was to assess the biomechanical action of different surgical approaches on the rib cage for the treatment of scoliosis using a patient-specific finite element model of the spine and rib cage. Several unilateral and bilateral rib shortening/lengthening procedures were tested at different locations on the ribs (convex/concave side of the thoracic curvature; at the costo-transverse/costo-chondral joint; 20 and 40 mm adjustments). A biomechanical analysis was performed to assess the resulting geometry and load patterns in ribs, costo-vertebral articulations and vertebrae. Only slight immediate geometric variations were obtained. However, concave side rib shortening and convex side rib lengthening induced important loads on vertebral endplates that may lead to possible scoliotic spine correction depending on the remaining growth potential. Convex side rib shortening and concave side rib lengthening produced mostly cosmetic rib cage correction, but generated inappropriate loads on the vertebral endplates that could aggravate vertebral wedging. This study supports the concept of using concave side rib shortening or convex side rib lengthening as useful means to induce correction of the spinal scoliotic deformity during growth, though the effects of growth modulation from induced loads must be addressed in more detail to prove the usefulness of rib shortening/lengthening techniques.     

人工腰椎间盘三维有限元模型的建立及其应力分析

目的 研究人工腰椎间盘三维有限元模型的建立及其应力分布。方法 利用有限元软件MSC MARK，建立人工椎间盘及L4-5运动节段的三维模型。并赋予各自生物材料特性，然后模拟腰椎节段的运动，研究人工椎间盘的应力分布。结果 建立了具有相应力学特性人工椎间盘和L4-5运动节段的模型。人工椎间盘的应力分布特点为：（1）在所有的运动状态中，滑动核及盖板的中心部位承受的应力最大，其次为滑动核在运动状态下偏向的部位；（2）滑动核及盖板上表面承受各自的下表面2-3倍的应力；（3）在所有的运动状态中，压缩状态下滑动核和盖板的中心部位承受的应力最大。结论 建立人工腰椎间盘三维有限元模型并进行其应力分析是可行的，结果是可信的。     

Anulus fibrosus tension inhibits degenerative structural changes in lamellar collagen

Mechanical stress is one of the risk factors believed to influence intervertebral disc degeneration. Animal models have shown that certain regimes of compressive loading can induce a cascade of biological effects that ultimately results in cellular and structural changes in the disc. It has been proposed that both cell-mediated breakdown of collagen and the compromised stability of collagen with loss of anular tension could result in degradation of lamellae in the anulus fibrosus (AF). To determine whether this may be important in the AF, we subjected entire rings of de-cellularized AF tissue to MMP-1 digestion with or without tension. Biomechanical testing found trends of decreasing strength and stiffness when tissues were digested without tension compared with those with tension. To determine the physiologic significance of tissue level tension in the AF, we used an established in vivo murine model to apply a disc compression insult known to cause degeneration. Afterward, that motion segment was placed in fixed-angle bending to impose tissue level tension on part of the AF and compression on the contralateral side. We found that the AF on the convex side of bending retained a healthy lamellar appearance, while the AF on the concave side resembled tissues that had undergone degeneration by loading alone. Varying the time of onset and duration of bending revealed that even a brief duration applied immediately after cessation of compression was beneficial to AF structure on the convex side of bending. Our results suggest that both cell-mediated events and cell-independent mechanisms may contribute to the protective effect of tissue level tension in the AF.     

Biological and mechanical consequences of transient intervertebral disc bending

Degenerative mechanisms for the intervertebral disc are unclear, particularly those associated with cumulative trauma. This research focuses on how mechanical loading at levels below those known to cause acute trauma can lead to cellular injury. Mouse-tail discs were subjected to static bending for 1 week, then allowed to recover unloaded for 3 weeks and 3 months. Discs were analyzed using histology, in situ hybridization (collagen and aggrecan gene expression), TUNEL assay for apoptotic cell death, and biomechanics. The bent discs demonstrated loss of annular cellularity on the concave (compressed) side, while the nucleus and convex annulus appeared normal. Chondrocyte-like cells were apparent within the inner, concave annulus on the recovered discs, with evidence of proliferation at the annulus/endplate interface. However, annular architecture and biomechanical properties for the recovered discs were not different from controls, suggesting that restoration of physiologic tissue stress prevents the inner annular degradation noted in previous compression-induced degeneration models. These data demonstrate that cellular injury can be induced by transient compressive stress, and that recellularization is slow in this avascular tissue. Taken together, this suggests that cellular damage accumulation may be an important injury mechanism that is distinct from acute mechanical failure.     

Histomorphological study of the spinal growth plates from the convex side and the concave side in adolescent idiopathic scoliosis

Asymmetrical growth of the vertebrae has been implicated as one possible etiologic factor in the pathogenesis of adolescent idiopathic scoliosis. The longitudinal vertebral growth derives from the endochondral ossification of the vertebral growth plate. In the present study, the growth plates from the convex and concave side of the vertebrae were characterized by the method of histology and immunohistochemistry to evaluate the growth activity, cell proliferation, and apoptosis. Normal zoned architectures were observed in the convex side of the growth plate and disorganized architectures in the concave side. The histological grades were significantly different between the convex and the concave side of the growth plate in the apex vertebrae (P < 0.05). The histological difference was also found significant statistically between end vertebrae and apex vertebrae in the concave side of vertebral growth plates (P < 0.05). The proliferative potential indexes and apoptosis indexes of chondrocytes in the proliferative and hypertrophic zone in the convex side were significantly higher than that in the concave side in the apex vertebral growth plate (P < 0.05). There was a significant difference of the proliferative potential index (proliferating cell nuclear antigen, PCNA index) between convex side and concave side at the upper end vertebra (P < 0.05). The difference of the proliferative potential index and apoptosis index were found significant statistically in the concave side of the vertebral growth plate between end vertebrae and apex vertebrae (P < 0.05). The same result was also found for the apoptosis index (terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate biotin nick end labeling assay, TUNEL index) in the convex side of vertebral growth plate between end vertebrae and apex vertebrae (P < 0.05). Some correlation were found between radiographic measurements and proliferation and apoptosis indexes. The difference in histological grades and cellular activity between the convex and concave side indicated that the bilateral growth plate of the vertebrae in AIS patients have different growth kinetics which may affect the curve progression.