实验性椎间盘退变的放射影像学与病理学观察

目的　研究椎间盘退变过程中 ,椎间盘退变的放射影像学与病理学改变。方法　选用 4 0只新西兰大白兔随机分为 2组 ,实验组切除兔腰椎间棘间、棘上韧带及棘突、关节突 ,造成力学失稳状态诱导形成椎间盘退变模型。术后一周、 3个月、 8个月时摄腰椎正、侧位X线片 ,观察腰椎影像学变化。第 3个月、 8个月时取腰椎间盘 ,进行组织检查 ,评定椎间盘退变的病理改变情况。结果　模型建立后 ,3个月、 8个月的X线片显现对照组无明显改变 ,实验组腰椎后突畸形 ,椎间隙狭窄 ,随着时间延长椎体软骨终板钙化更加明显。组织学观察发现 ,实验组随术后时间延长 ,髓核由椎间盘内脱出 ,并伴有椎间盘两侧软骨终板的纤维化即软骨终板发生退变。结论　椎体软骨终板的退变是椎间退变早期的主要表现方式。     

实验性椎间盘退变的放射影像学与病理学观察

目的 研究椎间盘退变过程中，椎间盘退变的放射影像学与病理学改变。方法 选用40只新西兰大白兔随机分为2组，实验组切除兔腰椎间棘间、棘上韧带及棘突、关节突，造成力学失稳状态诱导形成椎间盘退变模型。术后一周、3个月、8个月时摄腰椎正、侧位X线片，观察腰椎影像学变化。第3个月、8个月时取腰椎间盘，进行组织检查，评定椎间盘退变的病理改变情况。结果 模型建立后，3个月、8个月的X线片显现对照组无明显改变，实验组腰椎后突畸形，椎间隙狭窄，随着时间延长椎体软骨终板钙化更加明显。组织学观察发现，实验组随术后时间延长，髓核由椎间盘内脱出，并伴有椎间盘两侧软骨终板的纤维化即软骨终板发生退变。结论 椎体软骨终板的退变是椎间退变早期的主要表现方式。     

兔腰椎后外侧固定对邻近节段退变的影响及临床意义

目的观察兔腰椎后外侧固定对邻近节段退变的影响。方法成年新西兰大白兔24只,随机分成实验组和对照组,每组12只。实验组行腰椎后外侧横突间钢丝内固定术,并用骨水泥包绕横突及钢丝。对照组仅作相应的暴露而不行固定术。观察术后3个月、6个月时邻近节段椎间隙的影像学改变及椎间盘的组织学变化。结果侧位X片显示术后3个月时邻近的L3-4椎间隙轻度狭窄,6个月时狭窄进一步加重,并可见终板硬化,L6-7椎间隙则无明显狭窄。病理显示术后L3-4椎间盘随时间延长退变逐渐加重,而L6-7椎间盘则无明显退变性改变。结论腰椎后外侧固定会导致邻近节段的退变加速。     

兔椎间失稳软骨终板退变后弹性内固定作用的电镜实验研究

[目的]通过电镜观察研究弹性内固定重建椎间稳定的方法对软骨终板变化的作用机制,为椎间盘退变的临床治疗提供新的思路和方法。[方法]选取48只6个月龄日本大耳白兔,随机分组,分为实验失稳对照组和实验弹性内固定组,两组均为24只兔,将所有实验用兔进行手术椎间失稳;仅实验弹性内固定组在手术失稳2个月后用椎弓根螺钉和张力钢丝弹性内固定的方法进行L6、7的稳定性重建,均分别在内固定术后2、4、6个月取材。对椎间盘软骨终板用透射电镜观察,以判断软骨终板的退变过程。[结果]弹性内固定能明显阻止椎间盘软骨终板胶原纤维的退变,并可见软骨终板胶原纤维结构有部分恢复。[结论]弹性内固定能有效地阻止椎间盘软骨终板的退变;能有效促进软骨终板的修复。     

动静力失衡对大鼠颈椎不同节段椎间盘退变影响的显微CT形态学和组织学研究

目的:评价大鼠动静力失衡颈椎退变模型对C4～C7各节段终板磨损面积、椎间高度和椎间盘退变的影响,并分析终板磨损面积和椎间高度与椎间盘退变的相关性.方法:24只3月龄雌性SD大鼠随机分为模型组(14只)和对照组(10只).对照组仅做皮肤切口;模型组大鼠横向切断颈背部肌肉以及韧带,制作大鼠动静力失衡颈椎退变模型.术后12周、18周、24周分三次取大鼠颈椎标本.标本取材后进行显微CT扫描以及番红O快绿染色.测量C4/5、C5/6、C6/7各个节段椎间高度,计算上述三个节段的终板磨损比例,并对椎间盘退变程度进行评分.应用SPSS 13.0比较不同组相同节段椎间盘的终板磨损率,椎间高度和退变评分,并分析终板磨损率与椎间盘退变之间的相关性.结果:显微CT扫描发现模型组术后12周各个节段软骨终板均出现明显的磨损,磨损主要位于终板的腹侧.颈椎节段越高,磨损程度越轻.术后18周、24周,模型组C5/6、C6/7软骨终板磨损比例明显大于对照组,有统计学意义(P＜0.05).术后各个时间点,模型组不同节段终板磨损率情况不同,其中C6/7节段明显大于C4/5节段(P＜0.05).组织学切片显示,软骨终板的形态学改变早期以磨损为主,晚期则出现了大量钙化.术后12周,模型组C5/6、C6/7椎间高度明显低于对照组,术后18周、24周时高度进一步下降.术后12周,模型组的各节段椎间盘退变评分明显高于对照组(P＜0.05).术后24周时,模型组C4/5退变评分为11.5±1.0分,C5/6为11.8±1.0分,C6/7为12.8±0.8分.不同节段椎间盘退变评分差异有显著性(P＜0.05),其中C6/7椎间盘退变评分最高,明显大于C4/5、C5/6节段(P＜0.05).相关分析显示:终板磨损比例与椎间盘高度、椎间盘退变评分具有明显的相关性.结论:在大鼠动静力失衡颈椎退变模型中C6/7终板磨损比例较大,椎间盘高度降低出现较早,组织学上椎间盘退变程度也较严重,是该模型椎间盘退变的主要节段.软骨终板的形态学改变与椎间高度的降低和椎间盘退变程度有明显的相关性.     

兔椎间失稳软骨终板退变的实验研究

[目的]通过电镜研究软骨终板在椎间失稳环境下的退变过程,为椎间盘退变的治疗提供新的思路和方法.[方法]取48只6个月龄日本大耳白兔,雌雄不限,体重为(2.5±0.2)kg,随机进行分组,分为对照组和实验组,对照组为21只;实验组为27只;先将实验组兔腰背部皮毛剪除,用安定注射液1.25 mg/kg、氯胺酮0.02 g/kg、阿托品0.125 mg/kg顺次耳缘静脉注射麻醉后,俯卧固定于手术台上,用1%碘伏消毒手术区域,以髂嵴平对椎间隙(即L6.7)为中心,从正中取一长约4 cm纵行切口,切开皮肤及皮下组织,锐性分离,暴露棘突、椎板及上下关节突,将附着于棘突、椎板及小关节的肌肉全部分离开,然后依次切除L6.7棘上及棘间韧带,咬除第6腰椎两侧下关节突,造成椎间失稳,用无菌生理盐水冲洗切口,依次缝合各层组织;术后动物在笼中自由活动.实验组分别在术后2个月、4个月、6个月取材,对照组在相同条件下饲养后2个月、4个月、6个月取材;对椎间盘软骨终板用透射电镜观察软骨终板的结构,以综合判断软骨终板的退变过程.[结果]椎间失稳可导致椎问软骨终板胶原纤维结构由整齐有序、排列紧密向杂乱无章、排列松散退变.[结论]椎间失稳能明显导致椎间软骨终板的退变.     

软骨终板钙化在椎间盘退变过程中的作用机理

目的：研究椎体软骨终板钙化在椎间盘退变过程中的作用。人新西兰兔随机分为造模与对照组２组,每组发３个月和８个月２个观察亚组。切作造模组动物颈棘上、棘间韧带及分离颈椎后旁两侧肌肉,造成颈椎力学上的失衡而诱导兔颈椎间盘退行性改变。在术后３个月和８个地分别处死,取颈椎间盘组织,行病理学检查在形态学上评定颈椎间盘退变程度,测定不同退变程度椎间盘软骨终板钙化层厚度。结果：退变程度较轻或基本正常的颈椎间盘,软骨     

颈椎前路融合术对相邻节段终板影响的组织学观察

目的:观察颈椎前路融合术后相邻节段软骨终板的组织形态学变化,探讨颈椎前路融合术对相邻节段软骨终板的影响.方法:6只健康3～4岁雌性山羊,随机分为Ⅰ、Ⅱ组,每组3只.Ⅰ组为假手术组,仅切开显露颈椎椎体及椎间盘;Ⅱ组为实验组,行颈前路减压自体髂骨植骨钢板内固定术.手术节段均为C3/4.手术6个月后于腹腔注射麻醉下切取Ⅰ组及经X线证实手术节段已骨性融合的Ⅱ组山羊C2/3、C4/5上、下终板右侧组织块制备电镜标本,观察软骨终板细胞以及细胞外基质超微结构;空气栓塞法处死山羊,完整取下包含上、下终板及部分终板下骨质的C2/3和C4/5椎间盘,于正中矢状面上切取组织块制备光镜标本,行HE染色,测量软骨终板缺损的宽度并参考Ariga评价标准判定其退变情况,测量软骨终板钙化层厚度.结果:Ⅰ组软骨终板组织学表现正常,Ⅱ组83.3%出现轻度退变,两组比较有统计学意义(P<0.001);各组均未观察到中、重度退变情况.Ⅰ、Ⅱ组软骨终板钙化层厚度分别为71.9±2.3μm与92.6±14.2μm,两组比较有统计学意义(P<0.05).透射电镜观察显示,与Ⅰ组比较,Ⅱ组软骨终板细胞以及细胞外基质发生退变.结论:颈椎前路融合术可导致相邻节段软骨终板退变,而这种改变可能是引起相邻节段椎间盘营养障碍和退变的始动因素.     

前路融合对兔颈椎邻近节段椎间盘的影响

目的探讨前路融合内固定对兔颈椎邻近节段椎间盘的影响。方法60只新西兰白兔随机分4组,每组15只。1组为假手术对照组,余3组为实验组（分别为C34、C45、C56颈椎前路融合内固定组）。术后3、6、9个月每组取5只摄X线片,并取邻近上、下节段椎间盘做组织形态学检查,用免疫组化方法观察纤维环、髓核Ⅰ、Ⅱ型胶原的变化。结果随着时间的推移,实验组的X线片可见手术间隙融合,邻近节段椎体终板硬化;免疫组化结果：髓核中Ⅱ型胶原表达下降,纤维环中Ⅰ型胶原表达增加,随着时间的延长表现更为显著,Ⅰ型胶原有逐渐取代Ⅱ型胶原的趋势,胶原变化在C3-4、C4-5上、下邻近节段差异无统计学意义（P〉0.05）,而C56的下位邻近节段变化重于上位邻近节段,差异有统计学意义（P〈0.05）。实验组6个月与9个月分别与对照组6个月与9个月比较,差异有统计学意义（P〈0.05）。结论颈椎前路融合内固定可引起兔颈椎邻近节段的退变,不同水平融合内固定对邻近节段椎间盘的影响不同。     

软骨终板钙化与椎间盘退变关系的实验研究

目的　研究椎体软骨终板钙化与椎间盘退变的关系。　方法　通过切除２０ 只兔颈椎棘上、棘间韧带及分离颈椎后旁两侧肌肉造成颈椎力学上的失稳而诱导了颈椎间盘退变动物模型。在形态学上评定颈椎间盘退变程度,测定不同退变程度椎间盘软骨终板钙化层与非钙化层厚度。　结果　软骨终板钙化层厚度与椎间盘退变程度呈高度正相关性（ｒ＝ ０－９２） 。　结论　软骨终板的钙化可能是椎间盘退变的启动和促进因素     

颈椎前路钢板在下颈椎损伤的应用进展

对颈椎前路钢板在下颈椎损伤国外应用进展进行综述。颈椎前路钢板在设计上有限制性与非限制性两种类型,生物力学研究表明前者的固定强度明显优于后者,但易于在固定阶段对植骨块产生应力阻挡。手术指征主要为颈椎前柱损伤或颈椎后部骨与韧带复合体的损伤。但颈椎损伤存在高度不稳定时,前路钢板固定应联合颈椎后路稳定性手术。否则,术后须应用头环背心支具固定。对撑开屈曲型损伤,应警惕创伤性颈椎间盘突出,以免在牵引复位过程中发生严重的神经损伤。操作时应彻底解除脊髓前方压迫,植入三面皮质骨块,恢复前柱正常前凸,再行前路钢板固定。该方法的优点是达到了固定阶段即时稳定性,提高了植骨融合率,有利于康复。但加重了手术创伤,有发生与钢板或螺钉有关并发症的可能,晚期在临近融合区相邻椎间盘有退行性改变发生。因而在确定治疗方案时,要权衡利弊。     

Biomechanical comparison of anterior cervical spine locked and unlocked plate-fixation systems

Three different anterior plate-fixation systems are available for the stabilisation of the cervical spine: (1) the cervical spine locking plate (CSLP), (2) dynamic plates allowing vertical migration of the fixation screws, and (3) various types of plates that are secured with either monocortical or bicortical unlocked screws. Unicortical screw purchase does not involve the risk of posterior cortex penetration and possible injuries to the spinal cord. The development of locking plates with unicortical screw-fixation and intrinsic stability of the screw–plate interface, via an angle-stabilised connection, was an attempt to increase the stability of unicortical screw-fixation systems. The aim of the study was to compare the biomechanical properties of a non-locking, anterior-plate system with 4.5 mm screw fixation and a locking anterior-plate system, in a single destabilised cervical spine-motion segment. Using fresh cadaveric cervical spine specimen C3–C7, multidirectional flexibility was measured at the C4–C5 level in an unconstrained test system, before and after destabilisation and fixation with an anterior plate with either locked or unlocked screw purchase. Direct comparison of the fixed cervical spine segments with unlocked and locked anterior-plate fixation did not demonstrate significant differences. This in vitro study documented that neither locked nor unlocked anterior-plate fixation can increase stability in all modes of testing. H-plate spondylodesis with unlocked screws seems to provide sufficient mechanical integrity in most cases of monosegmental lesions.     

Histology and pathology of the human intervertebral disc

The intervertebral disc is a highly organized matrix laid down by relatively few cells in a specific manner. The central gelatinous nucleus pulposus is contained within the more collagenous anulus fibrosus laterally and the cartilage end plates inferiorly and superiorly. The anulus consists of concentric rings or lamellae, with fibers in the outer lamellae continuing into the longitudinal ligaments and vertebral bodies. This arrangement allows the discs to facilitate movement and flexibility within what would be an otherwise rigid spine. At birth, the human disc has some vascular supply within both the cartilage end plates and the anulus fibrosus, but these vessels soon recede, leaving the disc with little direct blood supply in the healthy adult. With increasing age, water is lost from the matrix, and the proteoglycan content also changes and diminishes. The disc-particularly the nucleus-becomes less gelatinous and more fibrous, and cracks and fissures eventually form. More blood vessels begin to grow into the disc from the outer areas of the anulus. There is an increase in cell proliferation and formation of cell clusters as well as an increase in cell death. The cartilage end plate undergoes thinning, altered cell density, formation of fissures, and sclerosis of the subchondral bone. These changes are similar to those seen in degenerative disc disease, causing discussion as to whether aging and degeneration are separate processes or the same process occurring over a different timescale. Additional disorders involving the intervertebral disc can demonstrate other changes in morphology. Discs from patients with spinal deformities such as scoliosis have ectopic calcification in the cartilage end plate and sometimes in the disc itself. Cells in these discs and cells from patients with spondylolisthesis have been found to have very long cell processes. Cells in herniated discs appear to have a higher degree of cellular senescence than cells in nonherniated discs and produce a greater abundance of matrix metalloproteinases. The role that abnormalities play in the etiopathogenesis of different disorders is not always clear. Disorders may be caused by a genetic predisposition or a tissue response to an insult or altered mechanical environment. Whatever the initial cause, a change in the morphology of the tissue is likely to alter the physiologic and mechanical functioning of the tissue.     

一期前后联合手术减压内固定治疗严重下颈椎疾病

目的 探讨严重下颈椎疾患的一期前后联合手术的可行性和疗效。方法 全麻下一期前后路联合减压、前路带锁钢板固定及自体植骨或钛网加自体骨移植,后路侧块钢板固定9例和颈椎椎弓根固定8例。10例为严重的颈椎骨折脱位,7例为钳夹型颈椎病。结果 本组17例经3～36个月的随访,围手术期无明显并发症。脊髓功能都有不同程度改善。结论 严重下颈椎疾患的一期前后联合手术是可行的,具有稳定性好、病人康复快的优点。     

Bone remodeling after internal fixation with different stiffness plates: ultrastructural investigation

Fourty adult New Zealand rabbits were used in this experiment. Four rabbits served as control and the rest 36 divided into 3 groups, each of which was fixed respectively with methylmethacrylate, titanium and strain-less steel plate on left intact tibiae. The cortical bone beneath the plate was harvested at 2, 4, 8 and 12 weeks after operation and observed by means of with transmission electron microscope. The major ultrastructural changes after internal fixation with different stiffness plates were alteration of osteocyte life cycle, perilacunar matrix, and disorder of osteoclast-osteoblast coupling. The greater the stiffness of the plate, the greater the ultrastructural change.     

不同刚度接骨板内固定后骨改建的组织学观察及组织形态学测量

本实验用40只成年新西兰兔,4只作对照,另36只分3组。采用有机玻璃、钛合金和不锈钢三种不同刚度的接骨板,分别固定在兔左侧胫骨中段。术后2、4、8和12周截取接骨板下皮质骨,进行光镜观察和计算机显微图像定量分析。发现不同刚度接骨板内固定后对板下皮质骨的组织形态具有不同的影响。接骨板刚度愈大,固定时间愈长,骨量丧失愈严重。     

颈椎前路带锁钢板治疗颈椎爆裂骨折的试验及临床研究

目的 评价颈椎前路带锁钢板固定系统(CSLP)治疗颈椎骨折的稳定性及临床有效性.方法 将6具新鲜成人颈椎标本(C2～6)置于脊柱三维测量仪上测定C3～5节段的ROM,制造C4爆裂骨折,测定其三维运动变化后分别进行植骨、植骨+CSLP固定,并重复测量其三维运动.对32例下颈椎骨折行前路减压融合,并以CSLP进行内固定治疗.结果 植骨+CSLP固定后在屈伸、侧弯、旋转方向较损伤后明显下降,与正常值相比,屈伸和侧弯运动均明显减少,但旋转运动减少不明显.术后随访6～48个月,所有骨折均复位,颈椎椎体高度恢复,椎间植骨均融合,钢板位置满意,无螺钉松动或脱出.结论 AO前路钢板固定颈椎爆裂骨折时各个运动方向均能获得稳定,临床效果满意,是一种治疗颈椎骨折的理想固定装置.     

颈椎带锁钢板在急性颈椎间盘突出症中的应用

目的：探讨颈椎带锁钢板在急性颈椎间盘突出症的应用价值。方法：20例急性颈椎间盘突出症患者施行颈前路减压、自体髋骨植骨及颈椎带锁钢板内固定术。结果：20例均获得随访6-24个月，平均随访时间13个月。所有病例植骨完全愈合，无一例发生钢板螺钉松动、断裂等并发症，结论：颈椎前路带锁钢板应用于急性颈椎间盘突出症可显著提高植骨融合率，并可提供有效的固定节段稳定性。     

Anterior C2–C3 fixation with screws: proposal of a new technique and comparative mechanical assays

The technical difficulties involved in the anterior fixation of the C2–C3 vertebral segment by means of plates and screws, related to retraction of the structures around the vertebral segment, appropriate exposure of the site and positioning of the screws and plate, motivated the development of a new modality of fixation of this segment using only screws. Fixation of the C2–C3 vertebral segment according to the technique proposed requires less exposure of the vertebral segment and does not involve the technical difficulties of standard fixation with plates and screws. In order to study the mechanical properties of this new modality of vertebral fixation, mechanical tests were performed comparing the proposed technique (fixation solely with screws positioned in the craniocaudal direction) and routinely used fixation (H plate and screws). The tests were performed using 80 cervical spine segments from Landrace pigs aged 5 months. The vertebral segments fixed by the two techniques were divided into experimental groups of ten specimens each and submitted to mechanical tests of flexion, extension, lateral bending and rotation in a universal testing machine. The mechanical properties used to compare the results were the load necessary to produce a pre-established deformation and stiffness. No significant differences were observed between the values obtained for the production of the pre-established deformation in the flexion and rotation tests. In the extension and lateral bending tests, the mean values obtained for vertebral segments fixed only with screws were significantly higher. Analysis of stiffness showed no significant difference in the flexion, rotation and lateral bending tests, whereas in the extension tests, the mean values for the group fixed only with screws were significantly higher. The results of the mechanical tests performed showed that fixation of the C2-C3 segment only with screws was not inferior from a mechanical point of view when compared to fixation with H plates of the Orozco type.This study was supported by a grant from AOSpine/AOSLA.