不稳定Hangman骨折颈椎前后路融合金属植入物内固定方式的对比

背景：对于Hangman骨折,采用颈前路融合钢板置入内固定和后路C2椎弓根、C3侧块钉棒置入内固定,目前存在争议。目的：比较颈前路融合钢板置入内固定和后路C2椎弓根、C3侧块钉棒置入内固定治疗Hangman骨折的临床效果。方法：将26例Hangman骨折患者按随机数字表法分为2组,分别行颈前路减压植骨钛合金钢板置入内固定与后路C2椎弓根、C3侧块钉棒置入内固定治疗。结果与结论：与后路C2椎弓根、C3侧块钉棒置入内固定治疗比较,颈前路减压植骨钛合金钢板置入内固定治疗手术时间更短,术中出血与术后引流量更少（P〈0.05）。两组术中、术后并发症差异无显著性意义。提示与颈椎后路手术内固定相比,颈椎前路融合植入物内固定手术治疗Hangman骨折手术时间短,术中出血量少,术后颈椎功能恢复良好。     

颈前路融合固定治疗不稳定Hangman骨折15例分析

目的探讨不稳定型Hangman骨折前路C2～3植骨融合结合内固定手术的疗效。方法15例不稳定型Hangman骨折（其中Ⅱ型9例、ⅡA型6例），行颈前路C2～3间盘切除，髂骨植骨融合，结合zephir前路锁定钢板内固定。结果术后随访平均10个月，颈部症状明显缓解，颈椎生理曲度维持良好，脊髓功能改善，植骨融合率100％，有2例椎弓骨折未愈合，无内固定松动及断裂现象。结论应用颈前路植骨融合内固定术治疗不稳定型Hangman骨折（Ⅱ型及ⅡA型）术后能获得即刻稳定；植骨融合率高，并维持颈椎生理前凸；对颈椎功能影响小。是目前治疗此类损伤较为理想的方法。     

后路钉棒内固定系统在不稳定性枢椎骨折治疗中进钉点与固定方式的选择

背景：上颈椎后路钉棒内固定过程中,放置寰椎侧块螺钉技术是关键。目的：总结后路钉棒内固定系统在不稳定性枢椎骨折治疗中的进钉点位置。方法：2007-01/2010-12采用Vertex颈椎后路钉棒内固定系统治疗不稳定性枢椎骨折19例,男12例,女7例,年龄21~75岁,平均49.5岁。采用寰椎侧块螺钉及枢椎椎弓根螺钉内固定6例,寰椎侧块、单侧枢椎椎弓根及颈3侧块螺钉内固定3例,寰椎侧块、双侧枢椎椎弓根及颈3侧块螺钉内固定1例,枢椎椎弓根及颈3侧块螺钉内固定9例,内固定过程中均行后侧椎板间植骨融合。结果与结论：19例患者全部获得随访,随访时间7~43个月。患者骨折复位满意,骨折端均获得愈合,植骨部位融合率达到100%,未出现断钉、断棒等现象,未发生颈髓及椎动脉等医源性损伤。该方法治疗不稳定性枢椎骨折创伤小,固定可靠,作者根据临床经验,对螺钉进钉点的位置总结如下：①对于寰椎侧块进钉点选择在侧块中点稍偏外、椎弓的下方1/3处,进针方向为向内、上分别稍倾斜约10°,5°。②枢椎椎弓根进钉点选择在枢椎上下关节面间、下关节正中垂线的中点,进针方向为向内、上分别倾斜15°~20°,25°。③第三颈椎侧块进钉点选择在侧块中心点内侧2mm,进针方向为向外、上倾斜20°~25°。     

后路钉棒内固定系统在不稳定性枢椎骨折治疗中进钉点与固定方式的选择

背景:上颈椎后路钉棒内固定过程中,放置寰椎侧块螺钉技术是关键。目的:总结后路钉棒内固定系统在不稳定性枢椎骨折治疗中的进钉点位置。方法:2007-01/2010-12采用Vertex颈椎后路钉棒内固定系统治疗不稳定性枢椎骨折19例,男12例,女7例,年龄21~75岁,平均49.5岁。采用寰椎侧块螺钉及枢椎椎弓根螺钉内固定6例,寰椎侧块、单侧枢椎椎弓根及颈3侧块螺钉内固定3例,寰椎侧块、双侧枢椎椎弓根及颈3侧块螺钉内固定1例,枢椎椎弓根及颈3侧块螺钉内固定9例,内固定过程中均行后侧椎板间植骨融合。结果与结论:19例患者全部获得随访,随访时间7~43个月。患者骨折复位满意,骨折端均获得愈合,植骨部位融合率达到100%,未出现断钉、断棒等现象,未发生颈髓及椎动脉等医源性损伤。该方法治疗不稳定性枢椎骨折创伤小,固定可靠,作者根据临床经验,对螺钉进钉点的位置总结如下:①对于寰椎侧块进钉点选择在侧块中点稍偏外、椎弓的下方1/3处,进针方向为向内、上分别稍倾斜约10°,5°。②枢椎椎弓根进钉点选择在枢椎上下关节面间、下关节正中垂线的中点,进针方向为向内、上分别倾斜15°~20°,25°。③第三颈椎侧块进钉点选择在侧块中心点内侧2mm,进针方向为向外、上倾斜20°~25°。     

颈椎骨折脱位前后路联合手术疗效报告

目的：探讨前后路联合手术在治疗颈椎骨折脱位中的价值。方法：12例颈椎骨折脱位伴脊髓损伤的患者，均在全麻下行颈前后路联合手术，减压、复位、钛网植骨及ORLON钢板前路固定前后路联合与后路双侧侧块钢板固定。结果：随访患者中，平均随访时间11．6个月。骨折、脱位复位理想，植骨术后3～6个月融合，无钢板镙钉松动、断裂。结论：严重颈椎骨折脱位伴脊髓损伤选择颈椎前后路联合手术获得了满意的复位、神经功能的改善和即刻稳定性的重建。     

颈椎一期前后路手术治疗颈椎骨折脱位患者的护理

严重创伤引起的下颈椎骨折脱位,往往需要颈椎固定和融合.一期前后路联合手术是目前治疗颈椎三柱损伤的有效方法之一.该手术包括前路行病变椎体次全切除,椎管减压,植骨融合,后路侧块螺钉和椎弓根螺钉固定.     

腰骶部结核的手术治疗

[目的]探讨后路椎弓根内固定、前路痛灶清除植骨融合治疗腰骶椎结核的临床疗效.[方法]2004年1月至2007年9月手术治疗腰骶椎结核15例,采用后路椎弓根钉棒系统内固定及前路病灶清除、植骨术,术前术后常规抗痨治疗,并定期随访,复查血沉,摄X线片.[结果]随访6个月至3年,平均21个月,结核病灶区无复发、植骨块融合、内固定无松动.无其他并发症,无复发.植骨融合时间4～8个月.[结论]后路椎弓根钉棒系统内固定及前路病灶清除、植骨是治疗腰骶段脊柱结核的有效方法.     

颈椎侧块钢板内固定材料植入技术在颈椎骨折脱位后路治疗中的特点

为探讨颈椎侧块钢板内固定植入技术在颈椎后路手术中的应用情况及特点,在颈椎后路手术中采用颈椎侧块钢板内固定加植骨融合术治疗颈椎骨折脱位患者12例。手术由后正中入路,颈椎骨折脱位根据情况复位,一侧或双侧椎板减压,采用Magerl法进钉,选用3.5mm皮质螺钉,双皮质固定。结果表明,术后3~5个月获得良好骨性融合,颈椎椎间高度无丢失,无螺钉松动及断钉现象,脊髓神经功能有不同程度的恢复。可见颈椎侧块钢板固定植入技术的手术操作相对简单,固定节段短,力学强度好。     

后路钉棒系统置入内固定并侧前方减压植骨融合治疗胸腰椎严重爆裂骨折12例

背景:胸腰椎爆裂性骨折侧前方减压植骨融合、钉棒系统内固定术可通过同一切口实现。目的:观察后路钉棒系统置入内固定并侧前方减压植骨融合治疗胸腰椎严重爆裂骨折合并脊髓及神经根损伤的临床疗效。方法:回顾采用后路钉棒系统置入内固定,侧前方减压植骨融合治疗12例胸腰椎爆裂骨折合并神经损伤的病例。结果与结论:12例患者椎管均获得有效减压,均随访9个月以上。影像学显示植骨块融合良好,伤椎高度基本恢复,Cobb’s角由术前平均22°恢复到6°,Frankel分级恢复1级者6例,恢复2级者3例,无变化者3例。结果表明,采用后路钉棒系统内固定加侧前方减压椎体次全切除植骨融合是集减压、复位、内固定、植骨融合、矫正畸形、重建脊柱稳定一次完成的有效方法,但应严格掌握适应证。     

后路钉棒系统置入内固定并侧前方减压植骨融合治疗胸腰椎严重爆裂骨折12例

背景：胸腰椎爆裂性骨折侧前方减压植骨融合、钉棒系统内固定术可通过同一切口实现。目的：观察后路钉棒系统置入内固定并侧前方减压植骨融合治疗胸腰椎严重爆裂骨折合并脊髓及神经根损伤的临床疗效。方法：回顾采用后路钉棒系统置入内固定,侧前方减压植骨融合治疗12例胸腰椎爆裂骨折合并神经损伤的病例。结果与结论：12例患者椎管均获得有效减压,均随访9个月以上。影像学显示植骨块融合良好,伤椎高度基本恢复,Cobb’s角由术前平均22°恢复到6°,Frankel分级恢复1级者6例,恢复2级者3例,无变化者3例。结果表明,采用后路钉棒系统内固定加侧前方减压椎体次全切除植骨融合是集减压、复位、内固定、植骨融合、矫正畸形、重建脊柱稳定一次完成的有效方法,但应严格掌握适应证。     

Biomechanical comparison of cervical discectomy/fusion model using allograft spacers between anterior and posterior fixation methods (lateral mass and pedicle screw)

BackgroundThe purpose of this study is to investigate effects of different fixation methods on the physical stress on allospacers, endplate-vertebral body, and implants using finite element model analyses.MethodsStress distribution and subsidence risk according to the fixation methods under the condition of hybrid motion control were analyzed. The detailed finite element model of a previously validated, three-dimensional, intact cervical spinal segment model, with C5–C6 segmental fusion using allospacer, was used to evaluate the biomechanical characteristics of different fixation combinations, such as anterior plate/screws, lateral mass screw, and posterior pedicle screw.FindingsThe load sharing on allospacers increased in extension in order of posterior pedicle screws (21.4%), lateral mass screws (31.5%), and anterior plate/screws (56.6%). lateral mass screw demonstrated the highest load sharing (68.1%) on the allospacer in flexion. The Peak von Mises stress of the allospacer was the lowest in flexion and axial rotation but the highest in extension with anterior plate/screws. Allospacer subsidence risk was the lowest in extension, lateral bending, and axial rotation with posterior pedicle screws but the lowest in flexion with anterior plate/screws. The bone-screw loosening risk was the lowest in all modes with posterior pedicle screws but the highest with anterior plate/screws.InterpretationPosterior pedicle screws demonstrated the best mechanical stability of allospacer failure-subsidence and the lowest risk of screw loosening. Different motion restrictions depending on the fixation method should be considered for implant and allospacer safety.     

胸腰段骨折不同固定方式的有限元分析

背景:对于不稳定的胸腰段骨折选择合适的内固定方式至关重要.目的:建立胸腰段爆裂骨折以及不同方式内固定有限元模型,进行不同方向加载后比较不同固定方式的生物力学特性.设计、时间及地点:对比观察,于2008/08-10在同济大学力学实验室完成.材料:采用德国西门子公司螺旋CT(64排)扫描一成年健康男性志愿者的T_(11)～L_1节段,间隔0.6 mm.采用布尔操作,去除T_(12)椎体下半部分,保留椎体的后部结构,建立胸腰段爆裂骨折的有限元模型.方法:试验分为5组,模型1为后路4钉2棒固定模型,模型2为后路5钉2棒(单侧伤椎固定)模型,模型3为后路6钉2棒(双伤病椎固定)模型,模型4为前路侧前方双棒固定模型,模型5为前后路联合固定模型.分别对于各模型进行前曲、后伸、左侧曲以及右侧旋转的加载,比较各模型的生物力学特性.主要观察指标:试验模型加载额定载荷后不同运动方向的Von Mises应力以及位移.结果:各种模型的运动状态中,应力从钉尖部至钉棒连接处逐渐增大,近钉棒连接处应力最大;近端螺钉受到的应力大于远端螺钉受到的应力.在试验的每种运动状态中,模型1的螺钉应力高丁模型2,3,高于模型5(P<0.01).模型5的稳定性最好;模型1各个方向位移最大,稳定性最差.结论:建立了不同固定方式的T_(12)椎体爆裂骨折固定模型,验证了在胸腰段骨折内固定治疗中,应用后路短节段固定结合伤椎固定及经椎弓根植骨治疗胸腰段骨折比单纯后路短节段固定具有更良好的生物力学特性.     

不稳定性枢椎椎弓骨折的外科治疗

目的探讨不稳定性枢椎椎弓骨折(Hangman骨折)的外科治疗方法。方法回顾性分析18例不稳定性Hang-man骨折患者临床资料,Levine-Edwards分型:Ⅱ型11例、Ⅱa型4例、Ⅲ型3例。11例行后路椎弓根螺钉固定术,4例行前路融合内固定术,1例行寰枢植骨、改良Gallie′s法Atlas钛缆内固定术,2例行枕颈融合后分别行Cervifix、CCD内固定术。结果所有患者均获得骨性愈合或骨性融合,时间3~4个月,颈椎获得良好稳定,无内固定失效。结论3种方法治疗不稳定的Hangman骨折各有优缺点及适应症。     

Biomechanical evaluation of anterior lumbar interbody fusion with various fixation options: Finite element analysis of static and vibration conditions

BackgroundAnterior lumbar interbody fusion combined with supplementary fixation has been widely used to treat lumbar diseases. However, few studies have investigated the influence of fixation options on facet joint force and cage subsidence. The aim of this study was to explore the biomechanical performance of anterior lumbar interbody fusion with various fixation options under both static and vertical vibration loading conditions.MethodsA previously validated finite element model of the intact L1–5 lumbar spine was employed to compare five conditions: (1) Intact; (2) Fusion alone; (3) Fusion combined with anterior lumbar plate; (4) Fusion combined with Coflex-F fixation; (5) Fusion combined with bilateral pedicle screw fixation. The models were analyzed under static and vertical vibration loading conditions respectively.FindingsBilateral pedicle screws provided highest stability at surgical level. Applying supplementary fixation diminished the dynamic responses of lumbar spine. Compared with anterior lumbar plate and Coflex-F device, bilateral pedicle screws decreased the stress responses of the endplates and cage under both static and vibration conditions, while increased the facet joint force at adjacent levels. As for comparison between Coflex-F device and anterior lumbar plate, results showed a similarity in biomechanical performance under static loading, and a slightly higher dynamic response of the latter under vertical vibration.InterpretationThe biomechanical performance of lumbar spine was significantly influenced by the variation of fixations under both static and vibration conditions. Bilateral pedicle screws showed advantages in stabilizing surgical segment and relieving cage subsidence, but may increase the facet joint force at adjacent levels.     

Do facet screws provide the required stability in lumbar fixation? A biomechanical comparison of the Boucher technique and pedicular fixation in primary and circumferential fusions

Background

Transfacet pedicle screws are scarcely used in primary posterior fixation, and have limited use unilaterally or with existing anterior instrumentation. Nevertheless, the incomplete literature suggests equivalent or better performance of ipsilateral, bilateral, facet screws compared to bilateral pedicle screws.

Methods

Two groups of seven human cadaver spines (L3-S1) were tested under pure moments of 6 Nm. Each specimen was tested in a primary and circumferential fixation (Spacer, Spacer + Plate) environment. Both transfacet and bilateral pedicle screws were used as posterior fixation, in separate groups. Motion was obtained at L4-L5 for single-level constructs in flexion-extension, lateral bending and axial rotation modes.

Findings

In primary fixation, both transfacet and bilateral pedicle screws reduced motion below intact levels. Statistically, the level of circumferential fixation (anterior, posterior, or both) proved to be more influential than the type of posterior fixation. Incorporating a spacer and plate with pedicle screws provided a greater relative gain in stability than with facet screws. The interpretation is explained through a model describing the location of fixation with respect to the center-of-rotation of the vertebral bodies. In lateral bending and axial rotation, bilateral pedicle screw constructs were stiffer than transfacet pedicle screw constructs as a trend.

Interpretation

Transfacet pedicle screws provided similar fixation to bilateral pedicle screws in primary and circumferential fixations during flexion-extension. In the other modes, transfacet screw rigidity is, on average, less than bilateral pedicle screws when used alone, but with the addition of other anterior instrumentation the differences are minimized. Therefore, facet screws are warranted based on the surgical effect desired, and in the presence of additional anterior fixation.     

Biomechanical testing of different posterior fusion devices on lumbar spinal range of motion

BackgroundRecent minimal-invasive posterior fusion devices are supposed to provide stability and obtain fusion in combination with interbody cages in the instrumented segment. The aim of the present study is to evaluate the primary stability of two minimal-invasive posterior prototypes compared to an established spinous process plate and standard pedicle screw instrumentation.MethodsSeven fresh frozen human cadaver lumbar spines (L2–L5) were tested in a spinal testing device with a moment of 7.5 Nm. Spinal stability was determined as mean range of motion (RoM) in the segment L3/L4 during extension-flexion, lateral bending and axial rotation. The RoM was measured during five conditions: 1. intact; 2. working prototype composed of an interspinous device and process plates; 3. an established spinous process fixation device 4. working prototype of facet fixation and 5. pedicle screw fixation.FindingsAll devices caused a significant reduction of RoM during extension-flexion. The RoM during lateral bending was significantly reduced to 37% (of intact) by pedicle screws and 68% by facet fixation prototype. During axial rotation the RoM was significantly reduced to 52% by pedicle screws and to 86% by facet fixation prototype. The other devices had no significant influence on RoM during lateral bending and axial rotation.InterpretationThe facet fixation prototype provided less primary stability compared to pedicle screws, but had significant advantages over spinous process fixation techniques. The results encourage further testing of this implant as a minimal-invasive approach for posterior fixation.     

Ⅰ期前后路联合重建不稳定下颈椎骨折脱位的临床观察

目的 分析Ⅰ期前后路联合手术重建不稳定下颈椎骨折脱位的近期临床疗效.方法 我院2006年3月至2009年7月对37例下颈椎严重骨折脱位患者,行Ⅰ期前路减压植骨融合钛板内固定,同期后路复位椎弓根螺钉内固定术.术前应用X线及64排CT明确骨折脱位下位颈椎的稳定程度,指导术前术式选择,同时测量椎弓根的宽度、高度,指导术中螺钉的选择.定期复查观察损伤节段的稳定性和融合率,采用ASIA分级判定脊髓功能的恢复情况.结果 28例患者获得随访,随访时间16.00～38.00个月,平均(22.37±6.93)个月.获得随访的患者,损伤节段稳定,颈椎椎体高度和生理曲度维持良好,融合率为100%,内固定位置良好.无椎动脉及脊髓损伤,无植骨决脱出或钢板、螺钉松动、断裂等并发症,脊髓功能评价平均提高1.30级,患者术后神经症状无一例加重.结论 Ⅰ期前后路联合重建治疗下颈椎骨折脱位,临床疗效满意,是一种可行的方法.     

腰椎间融合后路非对称与对称固定螺钉应力的有限元比较

背景：经椎间孔腰椎间融合非对称固定的生物力学稳定性研究,发现固定效果与双侧椎弓根螺钉接近,可满足临床应用所需生物力学要求。经关节突椎弓根螺钉参与经椎间孔腰椎间融合非对称固定的螺钉力学安全性又会怎样呢？目的：建立L4＋s功能节段左侧经椎间孔腰椎间融合后,分别予以同侧椎弓根螺钉＋对侧经关节突椎弓根螺钉、同侧椎弓根螺钉＋对侧经椎板关节突螺钉及双侧椎弓根螺钉固定的三维有限元模型,施加相同的载荷,分析不同运动状态下螺钉应力分布特点,比较3种螺钉应力状况。方法：对一成人正常L4—5椎节段标本、椎间融合器、椎弓根螺钉和皮质骨螺钉进行64排螺旋CT扫描,通过Mimicsll．1建立左侧经椎间孔腰椎间融合后3种内固定组合（同侧椎弓根螺钉＋对侧经椎板关节突螺钉、同侧椎弓根螺钉＋对侧经关节突椎弓根螺钉及双侧椎弓根螺钉固定）的几何模型,利用Simpleware3．1软件分别建立三维有限元模型,模拟500N惦Nm载荷下前屈、后伸、左＼右侧弯、左＼右侧旋等6种运动状态,用Abaqus6．8软件进行螺钉应力变化和分布特点分析。结果与结论：由于经椎间孔腰椎间融合入路切除了左侧关节突,造成内植物应力分布不对称,对弹性模量大的内固定器械一椎弓根螺钉应力影响最大,尤其是在左旋运动时。在不对称组合内固定中,由于关节突关节螺钉的使用,使对侧椎弓根螺钉应力相应增加,以左旋运动时尤为明显,但关节突关节螺钉断裂的危险性增高不明显。提示为降低螺钉断裂的风险,经椎间孔腰椎间融合后路3种组合内固定均应严格限制旋转运动,尤其是关节突切除侧的旋转运动。     

胸椎结核内固定手术治疗的术式选择

目的：探讨胸椎结核内固定手术治疗的术式选择。方法：选择1999年1月至2003年12月采用内固定手术治疗胸椎结核34例，采用不同的手术治疗方式。（1）前路病灶清除植骨、同期钢板内固定；（2）经肋横突切除入路行病灶清除植骨、同期椎弓根系统内固定；（3）后方入路行病灶清除、植骨融合和椎弓根系统内固定；（4）前路病灶清除植骨、后路椎弓根系统内固定。结果：随访1～3年（平均1．5年），无结核复发、螺钉松动、钢板断裂，17例有明显神经损害的患者术后均获得明显改善。四种术式在手术时间、出血量、后凸畸形矫正度和矫正丢失等方面存在差异。结论：脊柱稳定性在脊柱结核外科治疗中具有重要意义，根据胸椎稳定性改变选择合适的外科治疗术式，均可获得满意的临床疗效。