后路及单侧椎间孔和前路腰椎椎体间融合并置入椎弓根螺钉后相邻节段的生物力学变化

目的：比较经后路、单侧椎间孔、前路腰椎椎体间融合及附加椎弓根螺钉后相邻节段的力学性能。 方法：新鲜的雄性小牛L1~L5节段脊柱标本15具。随机取5只标本作为正常对照组,在非破坏状况下测试其力学指标后,再将15只标本随机分为3组,按要求制作L4/5前路椭圆形碳纤维Cage 1枚融合（前路腰椎椎体间融合组）、后路长方体碳纤维椎间Cage 2枚融合（后路腰椎椎体间融合组）和侧方椎间钛合金Cage 1枚融合（单侧椎间孔腰椎椎体间融合组）模型。测试完成后,每个标本附加L4/5节段双侧Moss-miamiTM椎弓根螺钉测试。 结果：3种融合方法在附加内固定前后应变和位移都高于正常对照组,强度低于正常对照组（P<0.01）,3组间以单侧椎间孔腰椎椎体间融合组变化最大,后路腰椎椎体间融合组最小（P<0.05）;在内固定前后配对比较,附加内固定后各组应变、位移增加,强度降低（P<0.05）。 结论：3种融合方法在附加内固定前后都有加速上位相邻节段退变的趋势,附加内固定比单纯融合更易导致相邻节段退变,单侧椎间孔腰椎椎体间融合退变趋势更加明显,后路腰椎椎体间融合的趋势相对较小。     

椎弓根螺钉置入内固定与单纯椎管减压治疗退行性腰椎滑脱的比较

背景：随着脊柱内固定和脊柱融合技术的发展,脊柱融合已成为腰椎退行性滑脱症毫无争议的“金标准”。同时,邻近节段退行性变的问题引起人们越来越多的关注。 目的：观察椎弓根螺钉内固定置入植骨融合治疗退行性腰椎滑脱的临床疗效、手术节段稳定性及其对相邻节段的影响,并与单纯椎管加压进行对比。 方法：选择天津医科大学总医院骨科收治的退行性腰椎滑脱患者38例,排除失访3例,余35例中采用椎弓根固定后外侧融合21例,单纯椎管减压14例。单纯椎管加压组用咬骨钳咬除黄韧带和椎板解除神经根后方的压迫,用骨凿凿除向前滑脱的椎体后缘与下位相邻椎体后缘形成的相对性突起;椎弓根螺钉固定植骨融合组按Wein-stein 法定位椎弓根钉进针,拧入椎弓根螺钉,根据受压情况进行椎板减压。按Oswestry功能障碍指数综合评价临床疗效,观察过伸、过屈位时的水平位移及角移位,采用UCLA系统来评价邻近节段退变情况。 结果与结论：35例患者随访时间1年。椎弓根螺钉固定植骨融合组优良率显著高于单纯椎管加压组(P < 0.05)。椎弓根螺钉固定植骨融合对腰椎稳定性影响不大,邻近节段退变置入前和置入后1年无明显变化。单纯椎管加压对腰椎稳定性影响显著,同时治疗前和治疗后1年邻近节段退变无明显变化。提示椎弓根螺钉内固定置入植骨融合治疗退行性腰椎滑脱疗效满意,对腰椎稳定性影响小,并且置入后早期对椎间盘的邻近节段影响不大。     

单侧椎弓根螺钉置入并椎间融合对邻近椎间盘节段退变的影响

背景：坚强内固定和良好融合存在严重缺陷和不足。目前还未见临床应用单侧椎弓根螺钉固定结合椎间cage植骨融合治疗腰椎退变性疾病对邻近节段退变影响的相关报道。 目的：回顾分析单侧椎弓根螺钉固定结合椎间cage植骨融合治疗部分腰椎退变性疾病后对固定融合邻近上下节段退变的影响。 方法：2006-03/2009-12对收治的部分腰椎管狭窄症、腰椎失稳及腰椎间盘脱出症患者22例,进行了单侧椎弓根螺钉固定加椎间cage植骨融合,术中不显露对侧。在固定融合后3,6,12,20个月及取出内固定钉棒后3,6个月,随访X射线片及MRI。针对X射线片运用角平分线法测量固定融合邻近上位椎间隙高度变化,MRI测量椎间盘髓核退变情况。 结果与结论：所有病例获得随访,患者椎管狭窄症状及神经根性症状消失,并且在随访期间内没有新的临床症状出现。固定融合前、固定融合后3,6,12,20个月邻近节段上位椎间隙高度分别为(7.420±0.035 4),(7.426 6±0.036 9),(7.453 3±0.036 9),(7.516 6±0.036 9),(7.430 8±0.036 9) mm,结果表明,腰椎单侧固定融合后邻近节段椎间隙高度无明显变化(P > 0.05)。MRI测量结果显示,固定融合邻近上位椎间盘髓核信号在T2加权像无明显退变。提示单侧椎弓根螺钉固定结合椎间融合治疗部分腰椎退变性疾病能有效预防固定融合邻近上下节段退变。     

腰椎后部结构切除对腰椎抗压强度的影响

本文测定了9个脊柱功能单位(functional spinal unit,FSU)的抗压强度,结果表明后部结构切除使腰椎抗压强度降低。本文指出手术中应尽量减少对后部结构的破坏,保持腰椎的稳定。     

不同融合方式对腰椎生物力学的影响

背景：腰椎融合已广泛应用于腰椎疾患,但腰椎融合后对邻近节段的影响尚存争议,不同融合方式的节段稳定性及对邻近节段的影响尚不清楚。 目的：利用动物模型研究腰椎融合节段生物力学稳定性及相邻上节段的生物力学特点。 方法：将新西兰大白兔随机分为前路椎体间融合组(切除L5~6椎间盘,终板去皮质化,自体髂骨移植)、后外侧融合组(L5~6双侧横突去皮质化后自体髂骨移植)、环状融合组(先行前路椎体间融合,1周后作后外侧融合)、对照组(不作手术)。术后12周处取标本作影像学检查、手触测试、生物力学测试。对融合标本分别施加屈伸,左右侧弯,左右旋转6个方向的纯力矩,比较不同融合方式融合节段的稳定性及邻近节段运动范围。 结果与结论：与对照组比较,前路椎体间融合组、环状融合组、后外侧融合组L5~6节段屈曲活动度分别下降86.24%(P < 0.05),88.74%(P < 0.05),73.10%(P < 0.05),融合节段近上节段L4~5屈曲运动范围分别增加52.22%(P < 0.05),55.89%(P < 0.05),27.11%(P < 0.05)。说明3种融合方式均显著提高融合节段稳定性,环状融合提供的节段稳定性最高,后外侧融合提供的节段稳定性最低。3种融合方式均使融合节段邻近上节段运动范围显著增加。前路椎体间融合,360°融合使邻近上节段屈曲运动范围增加无统计学差异。后外侧融合使邻近上节段屈曲运动范围增加最少。     

1000/胸腰段单节段骨折经椎弓根植骨结合短节段固定临床疗效评价

目 的 评价胸腰段单节段骨折经椎弓根植骨结合不同节段固定的临床治疗效果。方 法 自2005.1～2009.1年,资料完整并得到随访患者14例。所有患者骨折位置在T11～L2之间,椎体A型骨折,没有严重神经功能障碍。所有患者按照年龄分为A、B两组,A组：青壮年,平均年龄30.5岁（18～50岁）,7例,随访时间平均13.7个月（10～26个月）;B组：高龄组,平均年龄为65.9岁（51～79岁）,7例,随访时间平均14.4个月（11～24个月）。采用胸腰段后路经过椎弓根植骨及椎弓根螺钉系统内固定治疗,按照固定范围分为长节段固定和短节段固定。比较A、B两组患者手术时间、出血量、并发症及手术前,术后1周内,术后1年后骨折椎体高度及骨折节段后凸角度变化。结 果 所有患者术后脊柱后凸角度均得到明显矫正,骨折椎体高度得到明显恢复。随访1年后,A、B两组采用短节段固定者均发生一定程度的矫正角度丢失,但两组之间没有明显统计学差异。在A组虽然长、短节段固定组之间存在不同程度的矫正角度丢失,但无统计学差异;在B组采用长、短节段固定之间存在显著差异,P＜0.05。结 论 青壮年单节段胸腰段骨折患者后路经椎弓根植骨结合短节段固定临床疗效满意;高龄患者选择经椎弓根植骨结合长节段固定疗效更为理想。     

有限元法分析举重运动员预备提铃动作过程中腰椎节段的受力变化

背景：多年来,国内外学者对腰椎的生物力学特性进行了大量的研究,但是由于腰椎生理结构的复杂性以及研究手段的局限性,很多问题有待于进一步探索,特别是对举重运动员腰部损伤的防治是目前亟待解决的问题。 目的：建立人体完整腰段脊柱三维有限元模型,分析举重运动员预备提铃动作时腰椎节段的受力特点。 方法：引入“组装搭配式”思想,利用Dicom数据,建立人体脊柱腰椎节段(L1~5)完整的、真实的三维有限元模型。并模拟举重运动员预备提铃动作时,各椎体及椎间盘所受应力情况。 结果与结论：举重运动员预备提铃动作时,各椎体应力分布在椎体前下方,此处应力水平明显高于其他部位,椎体后部结构中椎弓根处出现应力集中现象,应力也处于较高水平。椎间盘应力分布在纤维环的中部和前部,但是前部更为明显。此时,不同椎体、腰椎间盘所承受的应力不同,其应力表现为自上向下呈逐渐增大趋势。各椎体的应力值大于其下方椎间盘的应力值,各椎体应力值是其下方椎间盘的四五倍。证实实验所建腰椎节段三维有限元模型可以用于模拟脊柱腰椎节段的生物力学特性研究。     

腰椎运动节段流固耦合有限元模型的建立与验证*

背景：传统的脊柱生物力学体外实验难以取得椎间盘液体相关的力学性能数据,国外可见多孔弹性有限元模型用于腰椎的固液二相性的研究,然而国内罕见相关报道。 目的：利用ANSYS12.1有限元分析软件,建立腰椎运动节段流固耦合有限元模型,旨在推动有限元分析技术在脊柱生物力学方面的广泛应用。 方法：对1名健康男性志愿者进行L4~5运动节段的螺旋CT扫描成像,利用医学图像处理软件Mimics10.01对其进行预处理,再利用逆向工程软件Geomagic9.0对模型进行NURBS曲面重构,然后导入有限元软件ANSYS12.1重建椎体皮质骨、松质骨、纤维环和髓核等结构,最后通过划分网格、定义材料属性、定义接触、加载求解等操作建立了腰椎运动节段流固耦合三维有限元模型,并将椎间盘高度随时间变化的数据与文献数据进行比较,以验证模型的有效性。 结果与结论：建立了L4~5运动节段的流固耦合有限元模型,模型的总节点数210 718个,总单元数85 973个。将本模型所测得的椎间盘高度数据与文献数据进行比较,结果基本一致。腰椎流固耦合有限元模型更加符合人体的生物力学特点。     

多节段脊髓室管膜瘤的显微外科治疗

目的 探讨多节段脊髓室管膜瘤的手术技术和手术治疗疗效。方法 本文回顾分析了2003年至2005年治疗的10例多节段脊髓室管膜瘤的临床资料。结果 颈髓室管膜瘤6例，胸髓室管膜瘤3例，1例术后复发肿瘤累及胸、腰髓并累及椎旁。平均累及脊髓9．4个节段。双下肢截瘫4例，高位截瘫6例，括约肌功能障碍5例，呼吸困难4例。MRI可见脊髓空洞形成8例。手术采用椎板复位9例，C-D钉棒系统脊柱后路内固定1例。术后患者肌力恢复7例，无改变3例。呼吸困难，应用呼吸机辅助呼吸1例。术后复查MRI无肿瘤残留9例，1例部分椎旁肿瘤残留。结论 采用显微神经外科技术可以达到镜下多节段室管膜瘤全切，患者术后症状大多数可以明显改善。多节段椎板切开术后应考虑椎板复位或脊柱内固定，以保持脊柱的稳定性。     

椎体后凸成形对邻近节段力学影响的有限元分析

背景：椎体后凸成形术自应用临床以来取得了令人鼓舞的临床效果,但是术后邻近椎体发生骨折时有报道。从生物力学角度来分析邻近椎体发生骨折的可能原因具有重要价值。 目的：以有限元方法观察椎体后凸成形术对相邻椎体生物力学的影响,分析相邻椎体继发骨折的原因。 方法：利用MIMICS软件对1例T12压缩骨折椎体后凸成形术前后的CT图片进行预处理,后导入ABAQUS软件中建立T10~L2的三维有限元模型,设置0.3,1.0 ,4.0 MPa三种轴向载荷进行生物力学分析,观察不同载荷下模型整体及各部分的Von Mises应力,重点评价椎体后凸成形术对骨折相邻椎体生物力学的影响。 结果与结论：成功建立了椎体后凸成形术前后的三维有限元模型,当轴向压力以0.3,1.0,4.0 MPa增加后,椎间盘、软骨终板和椎体整体的应力也成比例增加。椎体后凸成形术后脊柱胸腰段各部位的应力开始重新分布,增强椎体(T12)的相邻椎间盘(T11~12、T12~L1)及相邻终板(T11下终板、L1上终板)的应力增强区域增加;T12相邻椎体(T11,L1)所受最大应力明显增加,但远端椎体(T10,L2)的最大应力明显减少。提示椎体后凸成形术后引起上下相邻椎体继发骨折可能与术后生物力学行为的改变有关。     

金属植入物作用下腰椎后路3种融合方式的比较

背景：融合是腰椎减压椎弓根螺钉置入内固定后稳定运动节段的重要方式,经典的融合方式包括后外侧融合、后方椎间融合、后外侧融合并后方椎间融合。很多研究报道过几种融合方式的优势、技术要求、临床疗效和融合后并发症,但结论各异,很难明确最佳融合方式。 目的：比较后外侧融合、后方椎间融合、后外侧融合并后方椎间融合的疗效差异,以期寻求最佳融合方式。 方法：选择167例因退变性腰椎疾病行1个或2个节段融合,随访时间最短为3年的患者,分为3组,后外侧融合组62例,后方椎间融合组57组,后外侧融合+后方椎间融合组48例。通过目测类比评分、ODQ问卷和Kirkaldy-Willis 量表评价患者的腰痛、下肢疼痛和功能状况,并进行影像学评价,包括椎间盘高度、腰前凸、病变节段间角度、融合情况及融合后并发症。 结果与结论：最后1次随访结果表明,后外侧融合组患者中50例(80.7%)疗效优良,后方椎间融合组患者中50例(87.8%)疗效优良,后外侧融合+后方椎间融合组41例(85.5%)疗效优良,3组差异无显著性意义(P = 0.704)。3种融合方式都明显改善了椎间盘高度(P < 0.05),其中后外侧融合组椎间盘高度丢失最多,腰前凸和节段间角度明显增大,3种融合方式的节段间角度变化差异有显著性意义(P < 0.05)。最后1次随访时,3种融合方式的不融合率差异无显著性意义(P > 0.05)。治疗后并发症包括3例深部感染,4例暂时神经麻痹,1例永久神经麻痹,6例取骨处疼痛。提示3组融合方式在临床疗效和融合率方面无明显差异,后方椎间融合比后外侧融合能更好维持矢状面平衡。单纯后方椎间融合在缩短手术时间、减少失血量及避免取骨处疼痛方面有明显优势。     

Comparison of adjacent segment disease after minimally invasive or open transforaminal lumbar interbody fusion

Adjacent segment disease (ASD) is a potential long-term risk after lumbar fusion. Its incidence has been evaluated in anterior and posterior lumbar interbody fusions, but few studies have focused on transforaminal lumbar interbody fusion (TLIF). Relative risk of ASD with open or minimally invasive (MI) TLIF is poorly understood. To report our experience with risk for ASD in patients receiving TLIF and test its association with surgical approach, we performed a retrospective cohort study based on medical record review at a single institution. Eligible patients were ⩾18 years old at operation, underwent single-level TLIF during the period 2007–2008, and had at least 6 months postoperative follow-up. Patients were categorized by surgical approach (open versus MI). Primary outcome of interest was development of symptomatic ASD, defined by (1) new back and/or leg pain, (2) imaging findings adjacent to original surgical level, and (3) decision to treat. A total of 68 patients (16 open, 52 MI) were included in the analysis. Groups had similar baseline characteristics, except the open group tended to be older (p = 0.04). Seven (10%) patients developed ASD. Mean patient age was 62 years and three were male. Three underwent open and four underwent MI TLIF. Risk of ASD did not differ significantly by surgical approach. The MI group showed a trend toward decreased risk of ASD compared to the open group, although it was not statistically significant. This suggests MI TLIF may be associated with decreased long-term morbidity compared to the open approach. Large prospective studies are needed to confirm these findings.     

A novel substance P pathway linking the dorsal and ventral horn in the upper lumbar segments of the rat spinal cord

We report here the presence of a novel substance P pathway existing at a segmental level in the upper lumbar region (L₁/L₂) of the rat spinal cord. Substance P-containing fibres were seen directly linking a number of discrete areas of the rat spinal cord, including dorsal and ventral regions. These fibres were found closely associated with a specific group of motoneurones, the mediolateral motor nucleus in the ventral horn. This motoneurone group appeared as a ‘focusing’ nucleus around which substance P-containing tracts appeared to congregate.An intrinsic spinal cord origin of substance P-containing neurones in these interconnecting pathways is suggested as deafferentation achieved either by section of appropriate dorsal roots, or pharmacologically by neonatal treatment with capsaicin, had no effect on the appearance of the nucleus in the ventral spinal cord or of the associated substance P-containing tracts. Likewise, mid-thoracic lesions of the spinal cord (to determine supraspinal contributions) including hemisection, dorsolateral funiculus lesions and lesions of the region around the central canal, induced no change. The significance of these interconnecting substance P-immunoreactive fibre tracts is not known. However, the intimate association of substance P-containing fibres with a specific group of motoneurons indicates that they may modulate motor function.     

Effect of steerable cage placement during minimally invasive transforaminal lumbar interbody fusion on lumbar lordosis

Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) is commonly used for the treatment of a variety of degenerative spine disorders. Recently, steerable interbody cages have been developed which potentially allow for greater restoration of lumbar lordosis. Here we describe a technique and radiographic results following minimally invasive placement of steerable cages through a bilateral approach. A retrospective review was conducted of the charts and radiographs of 15 consecutive patients who underwent 19 levels of bilateral MIS-TLIF with the placement of steerable cages. These were compared to 10 patients who underwent 16 levels of unilateral MIS-TLIF with the placement of bullet cages. The average age, body mass index, distribution of the levels operated and follow-up were similar in both groups. The average height of the steerable cage placed was 10.9 mm compared to 8.5 mm for bullet cages. The preoperative focal Cobb’s angle per level was similar between both groups with a mean of −5.3 degrees for the steerable cage group and −4.8 degrees for the bullet cage group. There was a significant improvement in postoperative Cobb’s angle after placement of a steerable cage with a mean of −13.7 (p < 0.01) and this persisted at the last follow-up with −13 degrees (p < 0.01). There was no significant change in Cobb’s angle after bullet cage placement with −5.7 degrees postoperatively and a return to the baseline preoperative Cobb’s angle of −4.8 at the last follow-up. Steerable cage placement for MIS-TLIF improves focal lordosis compared to bullet cage placement.     

三维有限元腰椎节段模型上模拟拨伸按压手法的生物力学分析

背景：应用计算机技术和有限元法对传统中医推拿手法进行研究,给传统的中医推拿手法研究注入了活力。 目的：分析手法治疗腰椎间盘突出症的机制,探求符合生物力学的治疗手法,明确手法治疗腰椎疾患的安全范围。 方法：选择成年无腰椎疾患的男性志愿者,年龄28岁,身高170 cm,体质量60 kg。采用CT对L3~S1进行扫描,利用ADINA5.0构件软件,并赋予不同组织不同的材料属性,建立腰椎有限元模型,设定腰椎水平位、后伸10°位、前屈30°位状态,加载拔伸按压载荷,观察腰椎间盘、髓核和纤维环的受力改变情况。 结果与结论：在拔伸按压状态下,腰椎前屈30°椎间盘组织的位移应变和应力变化最明显,提示在设定的条件下手法治疗腰椎疾患是安全的。     

脊柱稳定性重建在腰椎不稳症中的应用

因腰椎退行性病变、创伤、肿瘤、峡部裂等因素造成的腰椎不稳和由此引起的下腰痛已引起广泛的关注,有近20%的腰椎不稳症患者非重建治疗效果不理想,需经重建治疗,目的是充分减压,重建脊柱的稳定性。重建脊柱稳定性的治疗方法种类很多,每一种方法又有其各自的特点,应根据不同患者选用不同的内固定方法并给予融合,以提高融合率, 缩短卧床时间,减少并发症。文章就脊柱稳定性重建的各种治疗方法的适应范围、特点和椎间融合等问题进行了综述。     

基于CT扫描及CAD技术建立下腰椎三维有限元模型

背景：近年来,计算机技术和有限元理论的飞速发展为构建腰椎模型提供了技术支持,有限元模型的精确性和可靠性显著提高,为研究椎间盘、椎板切除、腰椎融合、脊柱内固定材料等临床相关的生物力学问题提供了更好的平台。 目的：应用三维有限元法建立L3~5腰椎活动节段力学模型。 方法：通过CT扫描、Unigraphics V18.0软件进行影像边界记录、定标等方法,按照点、线、面、体的顺序重建三维结构,采用CAD数据处理技术,输入相关的材料特性,验证重建模型的有效性。 结果与结论：建立下腰椎的三维有限元模型(L3~5),分析结果证明其在仿真分析中是可行的,可以模拟生物力学实验。建立的模型共有6 482个节点,31 326个单元,生成网格时利用网格生成器的扫掠和优化功能,尽量依据模型的几何外形,使网格生成的最少,兼顾了对建模准确性和计算可行性,同时又能充分满足对腰椎的生物力学研究。     

Outcome of posterior lumbar interbody fusion versus posterolateral fusion in lumbar degenerative disease

Between March 2003 and September 2007, 170 consecutive patients with lumbar degenerative disease were studied retrospectively. Eighty patients underwent posterior lumbar interbody fusion (PLIF group) with pedicle screw (PS) fixation, and 82 patients underwent posterolateral fusion (PLF group) with PS fixation. Eight patients were lost to follow-up. The minimum follow-up period in each group was 2.0 years. The mean follow-up period for the PLIF group was 3.6 years, and for the PLF group, the mean follow-up was 3.4 years: there was no significant difference between the two groups for length of follow-up. The Pain Index (PI) improved from 66 to 27 in the PLF group (p < 0.001) and from 69 to 29 in the PLIF group (p < 0.001), but there was no significant difference between the two groups (p > 0.05). In the PLF group, the preoperative mean Oswestry Disability Index (ODI) score was 34.5, which reduced to 14.2 at the final follow-up. In the PLIF group, the mean preoperative ODI was 36.4, which reduced to 16.2 at the final follow-up. There was no significant statistical difference between the two groups for ODI (p > 0.05). Eighty-eight percent (n = 72) of patients in the PLF group and 91% (n = 73) in the PLIF group had radiologically confirmed union, with no significant difference in fusion percentage between the two groups (p > 0.05). Twenty-two of 162 patients (14%) underwent a second operation: 18 (22%) in the PLF group and four (5%) patients in the PLIF group (p < 0.001). The clinical and functional outcomes in both groups were similar, and no significant difference was found in the parameters tested. Both surgical procedures were effective, but patients in the PLF group showed more complications related to hardware biomechanics than patients in the PLIF group (p < 0.001).