胸腰椎骨质疏松性骨折自固化磷酸钙骨水泥椎体成形的实验研究

目的探讨自固化磷酸钙骨水泥(calciumphosphatecement,CPC)注射椎体成形术后对胸腰椎骨质疏松性骨折椎体的力学影响。方法自愿捐赠的4具甲醛固定的老年尸体,取胸腰椎骨质疏松标本,平均年龄69岁,男、女各2具。每具标本随机取6个椎体,制备24个单椎体标本,建立前屈方向加载单椎体骨折模型。将CPC粉末与固化液以2.5g∶1ml调和制备CPC骨水泥,对骨折标本行CPC成形强化,每个椎体注射CPC约4ml。分别进行骨折前、成形后屈曲压缩力学检测。结果骨质疏松椎体标本骨折前最大载荷为1954±46N,位移长度为5.60±0.70mm,刚度为349±18N/mm;骨折间隙CPC填塞成形后最大载荷为2285±34N,位移为5.35±0.60mm,刚度为427±10N/mm,各指标骨折前和成形后比较差异均有统计学意义(P<0.05)。CPC加强成形后单椎体的承载能力强度较骨折前提高16.92%,刚度较骨折前提高22.31%。结论椎体内注射CPC能明显恢复骨质疏松骨折椎体的力学性能。     

腰骶椎前路螺旋融合笼设计的解剖学依据

目的测量国人L3～S1终板凹陷深度(d)、椎间盘中央厚度(m)及椎体矢状径(S),找出兼顾机械稳定与生物融合效果的AFC直径和长度.方法用39具成人干燥腰骶椎骨L3～S1标本共156块,测量椎体中央高度(M)、椎体前后缘骺环处高度(A,P)及椎体上矢状径(S),并参考郭世绂椎间盘前后骺环处厚度值(a,p),通过统计学处理及几何运算,求得2d(±s)、S(±s)、m.结果L3、L4、L5的2d分别为3.95±0.75mm、4.02±0.82mm、4.01±0.55mm;L3、L4、L5、S1的S分别为29.72±1.71mm、30.18±2.15mm、30.58±1.94mm、30.69±1.88mm;L3/4、L4/5、L5/S1的m近似值为12～16mm、13～16mm、12～17mm,故AFC长度范围为15～26mm,AFC外直径范围分别是21～25mm、22～25mm、21～26mm.结论经前路椎体间正中前后向放置1枚AFC时,其所用AFC外径≈1/2(a+p)+12～16(mm);AFC长度≈S-6-S×滑脱百分比.     

颈胸段脊柱在模拟肿瘤破坏状态下稳定性预测的生物力学研究

目的评价颈胸段脊柱在模拟溶骨性肿瘤破坏的情况下的生物力学特性。从而为采取预防性稳定手术提供理论依据。方法取12具新鲜冷藏人体尸体脊柱标本(C7～T2),胸椎带有肋椎关节,分别进行完整标本和模拟颈胸段脊柱肿瘤溶骨性破坏状态时的生物力学测试。测试肿瘤破坏椎体面积的大小(完整标本,30%、40%、50%和90%的面积破坏)对脊柱稳定性的影响。结果椎体破坏面积从完整标本,30%、40%、50%和90%的面积破坏时,其屈服载荷分别为3549±254N、3203±223N、2822±182N、2707±174N和2510±176N。刚度分别从正常完整标本的910±210(N/mm),下降至781±90(N/mm)、664±60(N/mm)、585±40(N/mm)和482±30(N/mm)。T1椎体破坏面积在30%和40%时的屈服载荷有统计学显著性差异。结论在一定范围内,椎体破坏面积大小与椎体屈服载荷呈线性关系。颈胸段T1椎体在破坏面积达40%后,因稳定性下降容易出现椎体塌陷骨折和节段不稳,可作为外科采取预防性稳定手术的参考依据。     

基于CT技术的成年人腰椎间盘及终板解剖参数研究

目的:应用CT三维重建技术测量健康成年人腰椎间盘及椎体终板的解剖参数,为临床应用及腰椎间盘假体的个体化设计提供基本数据。方法:对2019年9月至2020年12月在新疆医科大学第二附属医院影像中心住院或门诊就诊腰椎正常椎间盘及椎体终板的解剖参数进行测量,男女各200例,年龄20~60(40.61±11.22)岁,测量节段为L_(1)-S_(1)椎间盘,测量指标包括椎间盘轴位前后径和横径、矢状位前中后高度、冠状位左右高度、椎间隙角度及各椎体上下终板的横径和前后径。结果:(1)在性别上,男性L_(1)-S_(1)椎间盘轴位前后径和横径、矢状位前中后高度、冠状位左右高度、椎间隙角度的解剖参数均大于女性(P<0.05),男性L_(1)-S_(1)椎体上下终板的解剖参数大于女性(P<0.001)。(2)在矢位前中后高度比较中,男性和女性L_(1)-L5各椎间盘矢位高度均为中高>前高>后高(P<0.001),而L5S_(1)椎间盘矢位高度为前高>中高>后高(P<0.001)。(3)在冠状位左右高比较中,男性和女性L_(1)-S_(1)椎间盘冠状位左右高度差异均无统计学意义(P>0.05)。(4)男性和女性L_(1)-S_(1)各椎间隙夹角均随椎体节段的增加而增大。(5)男性L_(1)-S_(1)椎体上下终板的前后径及横径均大于女性(P<0.001)。结论:在成人腰椎间盘假体的设计中应考虑性别差异。各节段腰椎间盘的解剖参数随椎体序列的增加而变化,在人工椎间盘的设计中应考虑不同椎间盘的解剖参数,从矢位的高度变化判定椎间盘的设计应为楔形。     

运动与骨盆牵引治疗胸腰椎压缩性骨折的疗效比较

目的: 对比运动疗法与传统骨盆牵引疗法治疗Ⅰ~Ⅱ度胸腰椎压缩骨折效果, 为运动疗法推广应用治疗胸腰椎压缩骨折, 提供合理的临床治疗依据。方法: 选择Ⅰ~Ⅱ度胸腰椎压缩的患者, 共计92例进入统计组。根据X线测量胸腰椎压缩骨折治疗前的椎体高度, 按照个人意愿分别采取运动疗法与骨盆牵引疗法, 根据治疗方法分组。1年后复查, 测量腰椎高度, 进行数据处理, 分析疗效差异。结果: 1年后随访, 压缩椎体高度变化, 1组: 治疗前为(17. 2±2. 3)mm; 治疗后为(24. 4±3. 1)mm; 2组: 治疗前为(16. 8±2. 6)mm; 治疗后为(23. 9±2. 7)mm。结论: 根据数据统计分析, 运动疗法与骨盆牵引疗法对Ⅰ~Ⅱ度胸腰椎压缩的患者治疗效果基本相近, 对于大多数Ⅰ~Ⅱ度胸腰椎压缩的患者, 如果他们能够积极配合, 可积极选用运动疗法。     

胸、腰椎椎体结核病椎置钉短节段内固定的疗效分析

 目的 总结胸、腰椎椎体结核前路一期病灶清除、椎体间植骨融合、病椎置钉短节段内固定的疗效,并探讨其安全性和有效性。方法 2009年6月至2013年11月,行前路一期病灶清除、椎体间植骨融合、病椎置钉短节段内固定治疗胸、腰椎椎体结核患者46例,男25例,女21例;年龄13~69岁,平均39.6岁。病变节段为T6~L4(均≤ 3个节段)。术前Frankel分级：B级3例、C级6例、D级4例、E级33例。术前后凸Cobb角平均为16.34°±3.19°。术前红细胞沉降率为19~81 mm/1 h。术前均行胸、腰椎CT平扫及二维重建,测量残余椎体冠状位及矢状位前、中柱最低有效残留高度,当最低残留有效高度>10 mm时,结合术中测量选择合适的内固定器械行前路病灶清除、植骨融合、病椎置钉内固定。对手术前后Cobb角、视觉模拟评分(visual analogue scale,VAS)、红细胞沉降率、Frankel分级行统计分析,并观察内植物稳定性和植骨融合情况。结果 46例患者随访12~48个月,平均26个月。所有患者结核中毒症状均消失,红细胞沉降率为0~15 mm/1 h。末次随访Frankel分级：D级2例、E级44例。术后1周后凸Cobb角平均为4.16°±2.71°,末次随访平均为4.52°±1.29°;VAS评分由术前(6.85±1.22)分,恢复至术后1周(4.79±0.95)分,末次随访时(2.26±0.93)分;红细胞沉降率由术前(41.25±1.61) mm/1 h,恢复至术后1周(17.36±6.82) mm/1 h,末次随访时(10.67±0.72) mm/1 h。术后6个月植骨融合优44例、良2例。结论 胸、腰椎椎体结核残余椎体有效高度>10 mm时行病椎置钉短节段内固定安全且可靠。     

应用Sky bone expander system经皮椎体成型术的生物力学评价

目的应用Sky bone expander system在体外经皮椎体成型术治疗椎体压缩性骨折,观察并评价生物力学性能。方法选取8具尸体脊柱标本(T10～L2)并游离成40个椎体,测定骨密度后随机分为3组；Ⅰ组为空白对照组(n=20)；Ⅱ组为球囊经皮椎体成型术组即球囊组(n= 10)；Ⅲ组为应用Sky bone expander system经皮椎体成型术组即Sky组(n=10)。在C型臂X线机导引下对Ⅱ和Ⅲ组椎体经双侧椎弓根行充填PMMA。在万能材料试验机上将所有椎体前缘压缩至原来高度的50%,测得最大载荷及刚度；然后将Ⅰ组在随机分为ⅠA组和ⅠB组,分别用球囊和Sky bone expander system行椎体成型术,再次按前述加载方法将椎体前缘压缩至充填后高度得50%,测得高度、最大载荷及刚度变化。结果实验前各组骨密度(BMD)为(0．298～0．650)g/ cm~2,高度为(1．87～2．83)cm。实验后Ⅰ组椎体的最大载荷为(2 632．75±64．83)N,刚度为(602．70±30．24)N/mm；Ⅱ组椎体的最大载荷为(5 215．60±70．46)N,刚度为(1 012．32±92．45) N/mm；Ⅲ组椎体的最大载荷为(5 320．75±92．38)N,刚度为(980．40±73．63)N/mm；最大载荷方面：Ⅰ组与Ⅱ、Ⅲ、ⅠA和ⅠB组间差异有统计学意义(P＜0．05)。刚度方面：Ⅰ组与Ⅱ、Ⅲ、ⅠA和ⅠB组间差异有统计学意义(P＜0．05),Ⅱ、Ⅲ、ⅠA和ⅠB组间差异无统计学意义(P＞0．05)。结论Sky bone expander system可有效的恢复椎体的生物力学性能,可为临床提供一种新的经皮椎体成型术方法。     

硫酸钙骨水泥在胸腰椎爆裂骨折椎体成形术中的生物力学性能

[目的]评价硫酸钙骨水泥(CSC)椎体成形术在胸腰椎爆裂骨折中的生物力学性能及临床应用价值.[方法]将16具新鲜小牛胸腰椎标本分为4组,A、B、C 3组制成爆裂骨折模型后分别实施CSC磷酸钙骨水泥(CPC)、聚甲基丙烯酸酯(PMMA)椎体成形术,D组为无骨折对照组.测量指标包括:爆裂骨折前、后与复位后及椎体成形术后的椎体前缘高度;达到完全填充时的3种骨水泥的注射量;生物力学检测4组标本的极限抗压强度及刚度.[结果](1)实验组12具标本均形成胸腰椎爆裂骨折模型,平均撞击能量为66.2 J;(2)CSC、CPC、PMMA的注射量分别为:4.4 ml±0.8 ml、3.7 ml±0.7 ml、4.0 ml±0.6 ml,组间无差别(P>0.05);(3)3种骨水泥均能有效充填爆裂骨折椎体复位后遗留的骨缺损,显著恢复了伤椎高度(P<0.01);(4)A、B、C、D组的极限抗压强度分别为:1 659 N±154 N、1 011 N±142 N、2 821 N±897 N及2 439 N±525 N.PMMA能够完全恢复骨折椎的抗压强度,CSC、CPC均只能部分恢复骨折椎的强度,但CSC优于CPC(P<0.01);(5)4组椎体的刚度分别为:(140±40)N/mm、(148±33)N/mm、(236±97)N/mm、(224±38)N/mm.CSC的刚度低于完整椎体68.0%,(P<0.05),但与PMMA、CPC无显著差异(P>0.05).[结论]经CSC椎体成形术的骨折椎强度优于CPC,刚度与PM-MA、CPC相当.将CSC椎体成形术作为一种辅助治疗方式用于胸腰椎爆裂骨折能满足力学要求,手术安全可行.     

椎体和椎间盘矢状面形态学改变对退变性脊柱后凸畸形的影响

目的：探讨椎体楔形变和椎间盘退变（塌陷）等形态学改变对成人退变性胸腰椎/腰椎后凸畸形的影响。方法：回顾性分析2015年8月至2020年12月收治的32例脊柱退变性胸腰椎/腰椎后凸畸形患者,其中男8例,女24例,年龄48~75（60.3±12.4）岁。在站立位全脊柱正侧位X线片上测量脊柱冠状面侧凸Cobb角和矢状面胸腰椎/腰椎后凸角（kyphosis angle,KA）,评估顶椎（apex vertebral,AV）及顶椎上下各2个椎体（AV-1,AV-2,AV+1,AV+2）与椎间盘（AV-1D,AV-2D,AV+1D,AV+2D）的高度及楔变参数,包括椎体前缘高度（anterior vertebral body height,AVH）,椎体后缘高度（posterior vertebral body height,PVH）,椎体楔变角（vertebral wedge angle,VWA）,椎体楔变率（ratio of vertebral wedging,RVW）;椎间盘前缘高度（anterior disc height,ADH）,椎间盘后缘高度（posterior disc height,PDH）,椎间盘楔变角（disc wedge angle,DWA）,椎间盘楔变率（ratio of disc wedging,RDW）,椎间盘贡献率（DWA/KA）。结果：所纳入患者KA为（44.2±19.1）°,后凸节段内椎体前缘高度均显著低于椎体后缘高度（P<0.05）,提示椎体发生不同程度楔形变;而后凸节段内椎间盘前后缘高度差异无统计学意义。后凸节段内椎体楔变率/贡献率分别为AV-2（14.98±10.95）%/（14.21±8.08）%,AV-1（21.08±12.39）%/（18.09±7.38）%,AV （26.94±11.94）%/（25.52±8.64）%,AV+1（24.19±8.42）%/（20.82±8.69）%,AV+2（20.56±7.80）%/（15.60±9.71）%,椎体总贡献率为（94.23±22.25）%;后凸节段内椎间盘楔变率/贡献率分别为AV-2D （2.88±2.57）%/（5.27±4.11）%,AV-1D （1.98±1.41）%/（2.29±2.16）%,AV+1D （-5.54±3.75）%/（-0.57±0.46）%,AV+2D （-8.27±4.62）%/（-1.22±1.11）%,椎间盘总贡献率（5.77±4.79）%,且顶椎贡献率明显大于邻近椎体贡献率（P<0.05）。结论：椎体楔形变及椎间盘塌陷共同构成了成人退变性胸腰椎/腰椎后凸畸形状态。就对后凸贡献率而言,椎体形态改变对后凸的贡献要远超椎间盘的贡献,且顶椎的楔形变对胸腰椎/腰椎后凸的贡献尤为明显。     

双源CT连续动态扫描评价腰椎不同曲度对椎间孔和椎间盘的影响

目的采用双源CT连续动态扫描评价腰椎不同曲度对腰椎间盘突出症患者腰椎间盘突出与椎间孔变化的影响。方法选取自2013-10—2014-10确诊的L4、5椎间盘突出症40例。仰卧位0°的位置为运动过程中动态扫描时的0°位置,根据腰椎矢状面Cobb角测量方法测量运动过程中伸展10°、20°和屈曲10°、20°的图像。测量腰椎间盘突出距离和椎间孔面积。结果在过屈位到过伸位运动过程中,L4、5椎间盘后缘突出程度逐渐增加,从中立位向过屈位运动时L4、5节段椎间盘突出程度变化更加明显。腰椎屈曲运动过程中腰椎每屈曲10°椎间盘突出减少(0.87±0.26)mm;伸展运动过程中腰椎每伸展10°椎间盘突出增加(1.24±0.45)mm。腰椎运动过程中,腰椎每伸展10°其椎间孔面积比仰卧位静态扫描时减小(8.02±0.34)mm~2;腰椎屈曲10°时,90%的患者椎间孔面积比常规仰卧位扫描时减小(6.72±0.23)mm~2;屈曲20°时,82.5%的患者L4、5节段椎间孔面积比静态扫描增时大(7.02±0.15)mm2。结论腰椎双源CT连续动态扫描可以明确诊断常规CT扫描阴性而下肢症状典型和常规CT结果与临床症状差异较大的腰椎间盘突出症患者。     

Lumbar facet joint and intervertebral disc loading during simulated pelvic obliquity

Background contextIntervertebral disc and facet joints are the two primary load-bearing structures of the lumbar spine, and altered loading to these structures may be associated with frontal plane spinal deviations.PurposeTo determine the load on the lumbar facet joint and intervertebral disc under simulated frontal plane pelvic obliquity combined loading, an in vitro biomechanical study was conducted.Study design/settingAn in vitro biomechanical study using a repeated-measures design was used to compare L4–L5 facet joint and intervertebral disc loading across pure moment and combined loading conditions.MethodsEight fresh-frozen lumbosacral specimens were tested under five loading conditions: flexion/extension, lateral bending, axial rotation using pure moment bending (±10 Nm), and two additional tests investigating frontal plane pelvic obliquity and axial rotation (sacrum tilted left 5° and at 10° followed by a ±10-Nm rotation moment). Three-dimensional kinematics, facet load, and intradiscal pressures were recorded from the L4–L5 functional spinal unit.ResultsSagittal and frontal plane loading resulted in significantly smaller facet joint forces compared with conditions implementing a rotation moment (p<.05). The facet joint had the highest peak load during the 10° combined loading condition (124.0±30.2 N) and the lowest peak load in flexion (26.8±16.1 N). Intradiscal pressure was high in lateral flexion (495.6±280.9 kPa) and flexion (429.0±212.9 kPa), whereas intradiscal pressures measured in rotation (253.2±135.0 kPa) and 5° and 10° combined loading conditions were low (255.5±132.7 and 267.1±127.1 kPa, respectively).ConclusionsFacet loading increased during simulated pelvic obliquity in frontal and transverse planes, whereas intradiscal pressures were decreased compared with sagittal and frontal plane motions alone. Altered spinopelvic alignment may increase the loads experienced by spinal tissue, especially the facet joints.     

CT辅助山羊腰椎解剖测量及与人体腰椎的对比研究

目的:通过对山羊腰椎的解剖测量以及与人体腰椎的对比研究,为腰椎假体的动物模型建立奠定基础。方法:通过计算机辅助软件Mimics 16.0对波尔山羊新鲜腰椎标本及健康成人腰椎的椎体、椎弓根、椎间盘等部位的解剖参数进行采集,最终运用统计学软件对两者腰椎解剖特点进行对比研究。结果:山羊椎体前高中高后高,最大值分别为(38.7±2.9)、(40.1±2.6)、(40.7±2.7)mm。其终板宽度大于其深度,整体呈心形或肾形外观。山羊上终板向外凸出,下终板凹陷较小,最大值为(1.6±0.6)mm。山羊椎弓根高自L1至L6不断增大,最大值为(30.5±1.9)mm;其椎弓根宽与夹角随着椎体序列的增加先减小后增大,最小值分别为(6.7±0.4)mm与(45.9±2.6)°。山羊椎间盘前高中高后高,三者随着椎间隙的变化数值波动较小;其椎间孔高与宽亦变化较小,分别在(12.9±0.3)~(14.3±1.0)mm与(5.7±1.0)~(6.7±0.9)mm波动。对比结果显示山羊腰椎椎体高、椎弓根高及夹角明显大于人类(P0.05),而其终板宽与深、椎间盘高等明显小于人类(P0.05)。此外,两者某些结构如椎弓根高、椎间盘高等随着椎体序数的增加亦呈现出不同变化规律。结论:山羊腰椎虽然在某些方面如终板及椎间孔形态等与人体存在相似性,但是在诸多方面仍存在较大差异。掌握山羊腰椎的解剖特点及与人体之间的差异对于腰椎假体及相关技术的山羊动物研究具有重要的指导意义。     

颈椎过伸伤患者MRI椎前高信号、椎管矢状径与神经功能的相关性分析

目的:探讨成人无骨折脱位型颈椎过伸伤患者MRI椎前高信号、椎管矢状径与神经功能的相关性。方法:回顾性分析2010年9月至2013年12月收治的无骨折脱位型颈椎过伸伤患者病例资料100例,根据MRI T2序列有无椎前高信号分为椎前高信号组和无椎前高信号组,其中椎前高信号组39例,男31例,女8例,年龄21～83岁,平均(58.10±14.78)岁;无椎前高信号组61例,男49例,女12例,年龄32～77岁,平均(55.05±10.36)岁。通过MRI正中矢状面测量下颈椎各椎间盘层面椎管矢状径,并记录年龄、性别、受伤原因及椎管狭窄节段数;采用美国脊髓损伤协会(American Spinal Injury Association,ASIA)神经功能分级及运动评分对神经功能进行评价。 结果:ASIA运动评分椎前高信号组为52.56±31.97,无椎前高信号组为67.70±22.83,两组差异有统计学意义(P=0.013);椎前高信号组患者的髓内高信号发生率明显高于无椎前高信号组(P=0.006);两组患者ASIA运动评分与损伤节段椎间盘层面椎管矢状径存在正相关(P=0.003),且椎管狭窄节段越多,ASIA分级越差。结论:成人无骨折脱位颈椎过伸伤MRI椎前高信号、椎管矢状径均与伤后神经功能相关,而存在多节段椎管狭窄的患者更易遭受严重的颈髓损伤。     

Mature runt cow lumbar intradiscal pressures and motion segment biomechanics

Background contextThe optimal animal model for in vivo testing of spinal implants, particularly total or partial disc replacement devices, has not yet been determined. Mechanical and morphological similarities of calf and human spines have been reported; however, limitations of the calf model include open growth plates and oversized vertebrae with growth. Mature runt cows (Corrientes breed) may avoid these limitations.PurposeThis study compared vertebral morphology and biomechanical properties of human and runt cow lumbar motion segments.Study designIn vivo disc pressure measurements were obtained in six mature runt cows at L4–L5. In vitro evaluation was performed on these same segments and repeated on 12 human motion segments.MethodsDisc pressures were measured in vivo in runt cow (Corrientes breed) L45 discs using a percutaneous transducer with the animal performing various activities. These motion segments were then harvested and morphologic and biomechanical evaluations (disc pressure in compression, flexibility tests to 7.5 Nm) were performed on both cow and male human L23 and L45 segments.ResultsThe transverse lumbar disc dimensions were slightly smaller for (mixed gender) cow versus (male) humans, but were within the range of reported (mixed gender) human values. The mean±SD disc height was smaller for runt cow (7±1 mm) versus human discs (13±2 mm, p<.001). The vertebral bodies of the cow were approximately twice as tall as the human. In vitro testing revealed significantly greater disc pressure response to applied axial loading in the runt cow versus humans (1.27±0.18 vs. 0.84±0.15 kPa/N, respectively) but similar overall stiffness (2.15±0.71 vs. 1.91±0.94 kN/mm, respectively). Runt cow and human segment flexibility curves were similar with the following exceptions: runt cow stiffness was ～40% greater in torsion (p<.05), runt cow segment lateral bending motion was greater versus humans (range of motion by 30%, neutral zone by 100%; both p<.05), and flexion range of motion tended to be smaller in runt cow versus human specimens (by ～40%, p=NS). In vivo, the standing disc pressure in the runt cow was 0.80±0.24 MPa.ConclusionsAlthough no animal replicates the human motion segment, the runt cow lumbar spine had a number of biomechanical and morphological measurements within the range of human values. The closed physes and temporally stable morphology of the mature runt cow may make this model more suitable versus standard calf models for human intradiscal implant studies.     

胫骨平台塌陷性骨折克氏针网状固定的生物力学评价

目的：评价采用克氏针束网状支撑固定治疗胫骨平台塌陷性骨折的生物力学性能。方法：在自行设计的骨折模型上,分别用8枚1．5mm克氏针网状固定和2枚3．5mm皮质骨螺钉固定,分别进行面压缩试验和点压缩试验,对这两种固定方式在最大抗压缩力、固定强度等方面进行生物力学评价。结果：面压缩试验中,平均最大抗压缩力,螺钉固定为（1925．31±444．26）N,克氏针束网状固定为（1609．62±277．72）N;平均最大固定强度,螺钉固定为（2．28±0．53）N／mm2,克氏针束网状固定为（1．90±0．33）N／mm2,两种固定方式生物力学性能接近（P〉0．05）;在点压缩试验组中平均最大抗压缩力,螺钉固定为（411．13±233．88）N,克氏针束网状固定为（1105．58±290．66）N;平均最大固定强度,螺钉固定为（2．66±1．52）N／mm2,克氏针束网状固定为（7．18±1．89）N／mm2,网状固定明显具有生物力学优势（P〈0．01）。结论：克氏针网状支撑固定胫骨平台骨折,对骨折施行生物学固定,固定牢靠。     

Three-dimensional digital measurement of the facet joint in normal individual and lumbar intervertebral disc herniation patients aged 13 – 18 years

BackgroundLumbar facet joint is an important element of spinal “three-joint complex”. Whether there is a relationship between strange structure of facet joint and adolescent lumbar disc herniation (ALDH) is nonetheless controversial, and the current research is mainly centered on adults.ObjectiveTo find out the normal lumbar facet joints between 13 and 18 years old to provide anatomical basis for early diagnosis and therapy of lumbar disc herniation.MethodsCT imaging information of 32 sufferers with lumbar disc herniation aged from 13 to 18 years old in Inner Mongolia have been collected as the ALDH group, and 62 wholesome subjects in the equal period had been chosen as the normal group. Uncooked records of continuous scanning lumbar tomography pix were imported into MIMICS 21.0 for evaluation and size in DICOM format. The parameters include facet joint height, facet joint width, et al.Results1. The left and right transverse angle of L₅S₁ segment in the ALDH group were (52.41 ± 9.2) ° and (55.99 ± 10.91) ° (P < 0.05), and the differences were statistically significant. The right side is larger than the left side. 2. Facet joint thickness in L₃-L₅ segment of the normal group was significantly higher than that of male (1.63 ± 0.32) mm than that of female (1.38 ± 0.25) mm; In 16–18 years old group, comparison of facet joint cross-sectional area was statistically significant (22.1 ± 3.04) mm² in male than (18.92 ± 3.71) mm² in female. 3. In comparison between normal and ALDH group, there was significant difference in L_3-4 transverse angle (P < 0.05), L_4-5 facet joint height and facet joint thickness (P < 0.05), L₅S₁ facet joint thickness and transverse angle (P < 0.05).ConclusionWhen ALDH occurs in the L₅S₁ segment, there is a substantial difference between the left and right sides of the transverse angle, and there is a difference in the thickness and the facet joint cross-sectional area between males and females, which is generally larger in males than in females. Facet joint height is larger, transverse angle of left and right is asymmetric, inferior articular process is larger, and facet joint thickness is smaller can indicate that lumbar disc herniation is effortless to occur.     

An investigation of range of motion preservation in fusionless anterior double screw and cord constructs for scoliosis correction

Purpose

To evaluate the motion-preserving properties of vertebral body tethering with varying cord/screw constructs and cord thicknesses in cadaveric thoracolumbar spines.

Methods

In vitro flexibility tests were performed on six fresh-frozen human cadaveric spines (T1-L5) (2 M, 4F) with a median age of 63 (59-to-80). An ± 8 Nm load was applied to determine range of motion (ROM) in flexion–extension (FE), lateral bending (LB), and axial rotation (AR) in the thoracic and lumbar spine. Specimens were tested with screws (T5-L4) and without cords. Single (4.0 mm and 5.0 mm) and double (4.0 mm) cord constructs were sequentially tensioned to 100 N and tested: (1) Single 4.0 mm and (2) 5.0 mm cords (T5-T12); (3) Double 4.0 mm cords (T5-12); (4) Single 4.0 mm and (5) 5.0 mm cord (T12-L4); (6) Double 4.0 mm cords (T12-L4).

Results

In the thoracic spine (T5-T12), 4.0–5.0 mm single-cord constructs showed slight reductions in FE and 27–33% reductions in LB compared to intact, while double-cord constructs showed reductions of 24% and 40%, respectively. In the lumbar spine (T12-L4), double-cord constructs had greater reductions in FE (24%), LB (74%), and AR (25%) compared to intact, while single-cord constructs exhibited reductions of 2–4%, 68–69%, and 19–20%, respectively.

Conclusions

The present biomechanical study found similar motion for 4.0–5.0 mm single-cord constructs and the least motion for double-cord constructs in the thoracic and lumbar spine suggesting that larger diameter 5.0 mm cords may be a more promising motion-preserving option, due to their increased durability compared to smaller cords. Future clinical studies are necessary to determine the impact of these findings on patient outcomes.

     

Volumetric analysis of thoracic and lumbar vertebral bodies

Background contextDuring the last decade, vertebral augmentation techniques with cement (kyphoplasty and vertebroplasty) have revealed that 75% to 100% of individuals with osteoporotic vertebral compression fractures have good to moderate pain relief postoperatively, as well as adequate restoration of the vertebral body height. The volume of cement injected into a vertebra varied in different reports. To our knowledge, there are no studies that report on the physiological distribution of thoracic and lumbar vertebrae body volumes.PurposeThe purpose of this study was to quantitatively evaluate thoracic and lumbar vertebral body volumes.Study design/settingForty computed tomography (CT) scans of the thoracic and lumbar spines were used to measure a volume of each vertebral body.MethodsForty CT scans with standard 2.5-mm bone window cuts of the thoracic and lumbar vertebrae (20 men and 20 women) were analyzed to measure the volumetric capacity of vertebral bodies using a BrainLAB Software (iPlan RT image 4.0) program. The software was tested for validity and reliability in two pilot studies. Mean and standard deviations for each vertebral body volume were calculated and recorded. The vertebral body working distance and the so-called “safe zone” were also measured to determine a size of a balloon to be used in kyphoplasty.ResultsVertebral body volume increased gradually from T1 to L4 with the exception of L5, which measured to be smaller than L4. The mean thoracic vertebrae volume was 15.0 cm³ (ranged in the absolute values from 5.2 to 39.5 cm³), and the mean lumbar vertebrae volume was 35 cm³ (ranged in the absolute values from 19.7 to 61.5 cm³). Men had larger volume vertebral bodies only in the lumbar spine compared with women. The average vertebral body working distances from T1 to T4 was 23.4±2.7 mm, from T5 to T9 was 30.3±3.6 mm, and from T10 to L5 was 35.5±3.9 mm.ConclusionsKnowing the physiological variability of vertebral body volumes may help prevent complications as a result of underaugmentation or overaugmentation with excessive amount of cement during kyphoplasty or vertebroplasty in osteoporotic compression fractures. We recommend using 10 mm balloons from T1 to T4, 15 mm balloons from T5 to T9, and 20 mm balloons from T10 to L5 for kyphoplasty.     

微创腰椎斜前方椎间融合术治疗退变性腰椎疾病的中早期疗效和并发症分析

目的:探讨微创经腹膜外斜前方入路椎体间融合术(oblique lumbar interbody fusion,OLIF)治疗退变性腰椎疾病的中早期疗效并分析其并发症.方法:回顾性分析2017年10月至2019年3月以OLIF术式治疗的退变性腰椎疾病患者22例,男14例,女8例,年龄51～72(63.15±7.22)岁,...