单节段腰椎活动度对邻近节段运动的影响

背景:有研究报道腰椎融合后其邻近节段运动范围和压力会明显增大;但也有报道腰椎融合与动态固定非融合或正常腰椎相比,其邻近节段运动范围和压力未见明显增加,甚至出现减少.然而,腰椎的活动度多少到底对邻近节段会有什么影响呢? 目的:观察单节段腰椎不同范围活动度对邻近关节运动范围的影响.方法:取6具新鲜成人L2～S2腰椎标本,依次对成人L4～L5椎体进行不同方式处理形成5种不同活动度状态:完整标本状态;部分失稳状态;动态固定状态;完全失稳状态;刚性固定状态.在脊柱三维运动试验机上,采用"载荷控制"法进行屈伸、侧弯和旋转等运动方向测试,分别将其他4个状态与完整标本状态进行比较.结果与结论:处理节段L4～L5椎体在各处理状态的下运动范围明显不同,形成了完全不同范围的活动度.与完整标本状态相比较,其他4个状态旋转时,上方邻近节段L3～L4的运动范围在刚性固定状态下明显减少;下方邻近节段L5～S1各方向和上方邻近节段L3～L4其余方向的运动范围无显著性差异.单节段腰椎刚性固定状态下,整个脊柱标本的运动范围明显减少.说明在"载荷控制"方法的实验下,单节段腰椎活动度多少对邻近节段的屈伸、侧弯等运动范围影响不明显,对上方邻近节段的旋转运动范围影响较大;腰椎刚性固定融合后,不一定要恢复到正常腰椎的活动范围,也许对预防邻近节段病有利.     

腰椎融合后邻近节段影像学评估方法的应用随访

背景:目前多数研究只分析了脊柱融合治疗紧邻融合区域头尾侧节段的术后改变,未对其他紧邻内固定的未作融合节段进行对照研究。目的:探讨腰椎邻近节段的测量方法,对腰椎后外侧融合后邻近节段的改变进行长期随访影像学评估。方法:选取尸体骨架6具,以不同投照方式和标本位置行腰椎侧位数字化标准X射线片共计42次(每具标本投照7次)。随访57例腰椎后外侧融合患者,随访时间1.5~4年,拍摄融合前及末次随访时的数字化标准X射线片,所有资料用失真代偿X射线分析法测量椎体间矢状角度、椎间盘高度、椎体间前后移位。结果与结论:失真代偿X射线分析法测量邻近节段矢状曲度、椎间盘高度、椎体间前后移位时,不同投照方式比较差异均无显著性意义(P>0.05)。固定节段尾侧椎体间未发现显著的影像学改变,固定节段头侧的多个椎体间矢状角度、椎间盘高度均有明显的改变。提示腰椎后外侧融合后影像学的改变提示固定节段头侧多个椎间盘加速退变。     

腰椎融合内固定对邻近节段退变的影响

背景：随着脊柱手术方法的成熟及内固定器械的发展,脊柱内固定融合术已成为许多脊柱疾患的主要治疗方法,但远期出现的邻近节段退变的问题也越来越突出。目的：回顾分析脊柱内固定后邻近节段发生退变的相关因素,有助于改善脊柱内固定的方法,减少远期并发症。方法：分别应用计算机检索维普、Pubmed数据库2005年1月至2012年12月关于脊柱融合内固定后邻近节段退行性变的文章,检索词分别设定为“脊柱融合内固定、邻近节段退变、单侧cage椎间融合固定”和“Adjacent segment degeneration、spine fusion、unilateral single cage”。筛选资料,选取脊柱融合后邻近节段退变的文献,筛除非随机试验的研究,将随机对照试验作为纳入标准,排除重复性研究文献。主要从术式、融合方式及邻近节段破坏等方面讨论脊柱融合后邻近节段退变的影响因素。结果与结论：筛选得到27篇符合纳入标准文献,从中得出融合节段数目、方式、部位及手术时对邻近节段小关节破坏是引起邻近节段退变的主要影响因素。人工椎间盘置换、单侧cage椎间隙植骨内固定在预防、延缓邻近节段退变上有一定作用。在决定融合固定术前,应综合考虑内固定材料、手术方式可能带来的影响,避免或降低邻近节段退变的发生。     

腰椎骨折与腰椎退变患者经腰椎后路植骨融合内固定后2年邻近节段退变的影像学表现

目的分析腰椎骨折与腰椎退变患者经腰椎后路植骨融合内固定后2年邻近节段退变(ASD)的影像学表现。方法选取2010年1月至2013年1月本院收治的36例腰椎骨折患者和30例腰椎退变患者分别设为骨折组和退变组。骨折组给予后路减压植骨融合内固定术治疗,退变组给予后路椎间融合术治疗。术后随访2年,并依据DR和改良Pfirrmann腰椎间盘突出MRI分级变化评估两组的ASD发生率。结果术后随访2年,骨折组的ASD发生率低于退变组,差异具有统计学意义(P<0.05)。结论腰椎退变患者内固定手术后对ASD影响大于骨折患者。     

OLIF治疗腰椎融合术后邻近节段退变性疾病的疗效观察

目的探讨斜外侧入路稚间融合术(OLIF)治疗腰椎融合术后邻近节段退变性疾病(ASD)的疗效。方法回顾性分析2017年6月至2019年12月18例行OLIF术治疗ASD患者的临床资料。记录手术时间、术中出血量、并发症、术后住院天数等。临床疗效评价采用视觉模拟量表(VAS)评分、日本骨科学会(JOA)评分和功能障碍指数(ODI)。摄腰椎正侧位X片,测量手术前后椎间隙高度(IDH)、椎间孔高度(IFH)和椎间孔面积(IFA)等影像学参数。摄腰椎CT三维重建评估植骨融合情况。结果平均手术时间(71±15)min(50~95 min),手术出血量(65±28)ml(20~200 ml),术后平均住院(7±2)d(4~9d)。随访时间12~36个月(平均18个月),术后末次随访的VAS评分、JOA评分和ODI指数比术前明显改善(P<0.05),影像学测量结果显示手术节段IDH、IFH、IFA由术前(5.5±0.6)mm、(15.3±1.4)mm、(135.3±6.5)mm分别增至术后(10.4±0.5)mm、(20.1±2.2)mm、(200.6±12.5)mm。术后2例患者出现术侧大腿前侧疼痛、屈髖无力,对症处理后症状消失。1例患者出现融合器下沉,但未出现临床症状,末次随访时椎间植骨已融合。所有患者术后1年植骨均获融合,未发现ASD复发。结论OLIP是治疗腰椎融合术后ASD的安全有效术式,获得满意的近期临床疗效。     

腰椎节段不稳的影响因素

目的：探讨腰椎节段不稳定的影响因素。方法选择57例L4～5节段不稳患者作为疾病组，22例L4～5节段手术患者作为术后对照组，19例健康检查者作为正常对照组。所有患者均拍摄正、侧位和过屈、过伸位X线片，CT扫描测量关节突形态，36例腰椎节段不稳患者行MRI检查，评价椎间盘退变情况。结果：前屈移位不稳患者关节突关节角方向偏向矢状，旋转不稳患者的椎间盘退变程度较轻，关节突全切患者存在前移不稳。结论：关节突矢状方向排列和椎间盘退变与前移不稳有关，可能是腰椎滑脱的原因，而韧带损害与旋转不稳有关。     

腰椎融合联合非融合技术预防邻近节段退变的应用分析

腰椎融合术后邻近节段退变是脊柱外科医师关注的焦点,非融合技术的出现为腰椎多节段退变疾病患者带来了希望,对退变严重、符合融合手术指征的节段应行融合手术治疗,而对于退变较轻、未达到融合标准的邻近节段可应用非融合技术予以保护,融合联合非融合技术治疗腰椎退变性疾病,不仅在早中期可取得良好的临床效果,而且可预防邻近节段的退变。且文献中术前对邻近节段退变程度评估标准不一,亟需一套统一科学的评估标准指导临床。     

腰椎退行性疾病的节段性融合

腰椎退行性疾病是常见病，其退变节段的病理性过度活动以及手术治疗过程中因退变节段稳定性进一步破坏所造成的腰腿痛症状采用节段性融合得到很好控制。过去的10年，新的用于脊柱融合的固定系统有了迅猛发展，进一步促进了节段性融合术在临床工作中的开展。现将有关问题报道如下。     

腰／腰骶部融合术后邻近节段病20例手术治疗分析

目的：探讨腰/腰骶部融合术后临近节段病（A SD）的发生机制及治疗方法。方法：回顾性分析20例腰/腰骶部融合术后邻近节段病,均行椎间融合术,术后早期行功能锻炼。结果：术后随访6～18个月,平均10个月,术后腰椎融合良好,融合率100%,无内固定物松动或植入物脱位等并发症发生。结论：利用融合术治疗因融合所致邻近节段病,能够明显改善患者症状,临床治疗效果满意。     

颈前路术后邻近节段退变研究进展

本文综述颈椎前路术后，目前国内外研究较多的是术后邻近节段发生的各种病理变化。通过查阅大量国外相关文献，整理、综合、分析颈椎前路术后邻近节段研究进展。结果表明，颈前路手术也从经典的自体髂骨取骨融合改良到单纯Cage植入融合再到前路植骨钉板固定融合手术，再到非融合技术邻近节段的退变是得到绝大多数的学者认同。融合术与目前非融合技术术式不同以及使用内固定方式的不同对邻近节段的影响也有不同，这也是术者在选择术式时除了临床疗效之外所要考虑的重要方面。     

Upper and lower adjacent segment range of motion after fixation of different lumbar spine segments in the goat: an in vitro experiment

ObjectivesThe purpose of this study was to examine the biomechanical effects of fixation on range of motion (ROM) in the upper and lower adjacent segments of different lumbar spine segments in a goat spine model.MethodsFifteen goat spine specimens (vertebrae T12–S1) were randomly divided into three groups: A (single-segment fixation), B (double-segment fixation), and C (triple-segment fixation). Motion in different directions was tested using a spinal motion simulation test system with five external loading forces. Transverse, forward–backward, and vertical displacement of the upper and lower adjacent segments were measured.ResultsAs the external load increased, the upper and lower adjacent segment ROM increased. A significantly greater ROM in group C compared with group A was found when the applied external force was greater than 75 N. The upper adjacent segment showed a significantly greater ROM than the lower adjacent segment ROM within each group.ConclusionsAdjacent segment ROM increased with an increasing number of fixed lumbar segments. The upper adjacent segment ROM was greater than that of the lower adjacent segments. Adjacent segment stability after lumbar internal fixation worsened with an increasing number of fixed segments.     

Single level lumbar laminectomy alters segmental biomechanical behavior without affecting adjacent segments

Background

Degenerative lumbar spinal stenosis causes neurological symptoms due to neural compression. Lumbar laminectomy is a commonly used treatment for symptomatic degenerative spinal stenosis. However, it is unknown if and to what extent single level laminectomy affects the range of motion and stiffness of treated and adjacent segments. An increase in range of motion and a decrease in stiffness are possible predictors of post-operative spondylolisthesis or spinal failure.

Methods

Twelve cadaveric human lumbar spines were obtained. After preloading, spines were tested in flexion-extension, lateral bending, and axial rotation. Subsequently, single level lumbar laminectomy analogous to clinical practice was performed at level lumbar 2 or 4. Thereafter, load–deformation tests were repeated. The range of motion and stiffness of treated and adjacent segments were calculated before and after laminectomy. Untreated segments were used as control group. Effects of laminectomy on stiffness and range of motion were tested, separately for treated, adjacent and control segments, using repeated measures analysis of variance.

Findings

Range of motion at the level of laminectomy increased significantly for flexion and extension (7.3%), lateral bending (7.5%), and axial rotation (12.2%). Range of motion of adjacent segments was only significantly affected in lateral bending (− 7.7%). Stiffness was not affected by laminectomy.

Interpretation

The increase in range of motion of 7–12% does not seem to indicate the use of additional instrumentation to stabilize the lumbar spine. If instrumentation is still considered in a patient, its primary focus should be on re-stabilizing only the treated segment level.     

腰椎运动节段终板凹陷角变化的有限元分析

背景：终板的组织形态改变可通过影响对椎间盘的营养传递最终导致椎间盘的退变。 目的：观察终板凹陷程度变化对腰椎运动节段牛物力学的影响。 设计、时间及地点：有限元模型生物力学分析。于2005—01／200701在浙江大学医学院附属第二医院骨科生物力学实验室完成。 材料：德国西门子SOMATOM SENSATION 16螺旋CT机。ANSYS有限元分析软件（Inc．Pennsylvania．USA）。 方法：在以往建直的腰椎L4～5运动节段三维非线性有限元模型基础上，采用CAD方法精确构建大、中、小3种不同终板凹陷角的有限元模型，有限元模型的椎间盘前凸角、小关节间隙等其余形态学参数及网格划分均保持一致。垂直压缩、屈曲、伸直、前后剪力5种载荷条件下，分别对3种有限元模型生物力学参数进行测试。 主要观察指标：终板椎间盘界面应变、椎间盘刚度、髓核内压、椎间盘膨出、纤维环纤维张应力、纤维环基质应力、腰椎后部结构应力以及关节突接触力。 结果：负载条件下，终板凹陷角增加、终板凹陷程度减小可导致终板-椎间盘界面应变减小，椎间盘刚度及髓核内压增加，椎间盘膨出、纤维环纤维张应力、纤维环基质应力、腰椎后部结构应力以及关节突接触力减小。 结论：终板凹陷程度的减小增强了椎间盘对椎体的保护作用；同时可通过影响终板的形变减少对椎间盘的营养传递。     

The effect of loading rate and degeneration on neutral region motion in human cadaveric lumbar motion segments

BACKGROUND: The quasistatic neutral zone is a surrogate for neutral region stiffness of spinal motion segments. No similar measure of dynamic stiffness has been validated. Because parameters related to stiffness are likely to be affected by loading rate and disc degeneration, we examined the effect of those factors on motion parameters derived from continuous motion data. METHODS: Fifteen human lumbar motion segments were tested with continuous flexion-extension pure moments at 0.5, 3.0 and 6.0 degrees /s. Range of motion, width of the hysteresis loop, transitional zone width, and slopes of the upper and lower arms of the hysteresis loop within the transitional zone were measured. Discs were then graded for degeneration. FINDINGS: As the loading rate increased from 0.5 degrees /s to 6.0 degrees /s there were significant increases in range of motion, hysteresis area, hysteresis loop width, and the upper and lower transitional zone slopes. At the same time transitional zone width decreased significantly. Degeneration had a significant effect on all parameters except hysteresis loop width. The transition zone slopes appeared to best discriminate between normal and degenerative discs. INTERPRETATION: Loading rate had a significant effect on all parameters. As degeneration increased consistent effects were observed indicating decreasing stiffness from grade 1 to grade 3 then slightly increased stiffness in grade 4 specimens. The slopes of the transitional zone have potential to be a useful measure of neutral region stiffness during dynamic motion testing.     

The effect of repeated extensions on the discographic dye patterns in cadaveric lumbar motion segments

Little is known about the effect of mechanical treatment on the intervertebral disc in the management of low back pain, even though good clinical results are often claimed for this treatment. In order to understand the possible effects of this treatment, cadaveric lumbar motion segments were studied with discography at 103 levels in 19 lumbar spine specimens. Fifty-four motion segments were tested with repeated extension/compression moments and evaluation of the changes in discogram dye pattern was made. In 43% increased dye leakage was observed, while 31% of those studied showed some degree of increased bulging, and in 2% there was evidence of decreased bulging. The major effect of repeated extensions moments on the cadaveric lumbar motion segment appears to lie in forcing dye from the nucleus pulposus into the spinal epidural space, or some peridiscal space in many abnormal discs.     

腰椎运动节段新型有限元模型建立及其生物力学意义

背景腰椎力学性质较常见的研究方法有动物模型、物理模型和尸体模型,但每种都存在一定局限性.目的建立腰椎运动节段的有限元模型,为腰椎生物力学研究提供理论依据.设计以健康志愿者为研究对象的单一样本研究.单位一所大学医院的骨科.对象实验于2003-12/2004-08在中南大学湘雅医院骨科研究室完成.选择1名健康男性志愿者作为模拟对象.方法对1名健康志愿者脊柱T12～S1节段进行层厚2 mm的连续扫描,共获得CT断层图像264幅,将CT扫描的腰椎图像结合人体解剖学数据通过3DSMAX软件建模形成正常中国男性L4-5运动节段的三维模型,用有限元分析软件SAP2000转换成有限元模型.主要观察指标①3DSMAX软件中椎体、椎间盘模型.②SAP2000软件中运动节段有限元模型.结果建立了腰椎L4～5节段的有限元模型,模型总节点数为2 120个,包括1728个Solid单元,592个Area单元,50个Link单元.结论通过CT断层扫描、图像数字化处理及计算机辅助设计等方法,可以建立腰椎运动节段的有限元模型,用于脊柱生物力学的进一步研究.     

颈椎前路融和后相邻节段退变的研究进展

脊柱椎体间植骨融合被公认为治疗颈椎疾患的一种疗效较好、并发症较少的手术方式，但远期并发症尤其是相邻上下节段退行性改变逐渐显现。本文介绍颈椎融和后相邻节段退行性改变的发生机制、影响因素、诊断、预防和治疗。     

Short term biomechanical effects of chymopapain injection; an in vitro investigation of human lumbar motion segments

Intradiscal injections of therapeutic doses of chymopapain were performed on specimens of the human lumbar spine. The changes in disc height, intradiscal pressure and endplate stress distribution, as well as in bending and flexion mobility, were observed during 8 hours after the injection. Injection of isotonic saline was used for controls. The injection effects a temporary increase in disc height (and consequently a decrease in radial disc bulge) and a temporary increase of the intradiscal pressure. The stress distribution and motion segment mobility remain unchanged. No difference is noted between the chymopapain series and the saline controls.     

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个.随机取5个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个标本随机分为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.