Validation of the intervertebral disc histological degeneration score in cervical intervertebral discs and their end plates

Background Context

Vertebral joints consist of intervertebral discs (IVDs) and cartilaginous end plates (EP) that lie superiorly and inferiorly to the IVDs and separate them from the adjacent vertebral bodies. With aging, both IVDs and EPs undergo degeneration. The Histologic Degeneration Score (HDS) is a grading system that microscopically evaluates the degree of degeneration in lumbar discs and predicts it with high accuracy basing on several histological markers of IVD and EP. There is currently a lack of validated histologic grading schemes for cervical spine degeneration.

细胞凋亡、细胞增殖在人颈椎间盘退变过程中的作用

目的 探讨细胞凋亡、细胞增殖在人颈椎间盘退变过程中的作用以及人颈椎间盘细胞凋亡可能涉及的信号转导途径.方法 收集手术切除的33份突出颈椎间盘组织,以22份正常人颈椎间盘组织作为对照,组织形态学和TUNEL法检测凋亡细胞,免疫组织化学法检测增殖细胞核抗原(PCNA)、bax及Caspase-3的表达.结果 实验组的细胞密度低于对照组(髓核内:6.30±1.54比8.96±1.14;软骨终板内:17.27±1.82比25.41±1.89);实验组的TUNEL阳性细胞率高于对照组(髓核内:11.73±1.36比7.02±1.26;软骨终板内:13.04±1.75PC6.86±1.42);实验组髓核内PCNA阳性细胞率高于对照组(8.38±1.98比4.55±1.54);实验组髓核内bax阳性细胞率和Caspase-3阳性细胞率分别高于对照组(bax:19.32±1.95比10.94±1.72;Caspase-3:15.05±1.74比8.92±1.48);TUNEL阳性细胞率与细胞密度之间呈负相关(P＜0.01);实验组髓核内PCNA阳性细胞率与细胞密度之间呈正相关(P＜0.01);两组髓核内bax阳性细胞率、Caspase-3阳性细胞率均与TUNEL阳性细胞率之间呈正相关(P＜0.01).结论 细胞凋亡与细胞增殖间的不平衡可能是人退变颈椎间盘内细胞密度下降的原因,人颈椎间盘髓核细胞的过度凋亡可能与bax和Caspase-3的表达上调有关.     

The biomechanical impact of facet tropism on the intervertebral disc and facet joints in the cervical spine

Background Context

Facet tropism is defined as the angular difference between the left and the right facet orientation. Facet tropism was suggested to be associated with the disc degeneration and facet degeneration in the lumbar spine. However, little is known about the relationship between facet tropism and pathologic changes in the cervical spine and the mechanism behind.

Morphological changes of cervical facet joints in elderly individuals

To better understand the role of facet joint degeneration in chronic neck and back pain epidemiological and morphological data are needed. For the cervical spine, however, such data are rare. Therefore, the aim of this study was to determine the degree of cartilage degeneration of cervical facet joints with respect to spinal level and age, to investigate whether any region of the joint surface is more often affected by degeneration and to determine the localisation of osteophytes. A total of 128 left-sided facet surfaces from 15 fresh frozen cervical spine specimens (59-92 years) including in maximum C2-C7 were inspected in a way to ensure a direct comparability to data reported for the lumbar spine. First, the macroscopic degree of cartilage degeneration was determined and correlated to spinal level and age. Then, each facet surface was divided into five regions (anterior, posterior, lateral, medial and central) to check whether cartilage degeneration occurs more often in any of these regions. Finally, the localisation of osteophytes was determined. The results showed that the mean degree of cartilage degeneration was 2.8 (+/-0.6) on a scale from Grade 1 (no degeneration) to 4 (severe degeneration). None of all 128 facet surfaces was classified as Grade 1. All spinal levels had about the same degree of degeneration (in mean 2.5-3.0). The youngest age group (<70 years) had a somewhat lower degree of degeneration (2.6) than the oldest (> or = 90 years) (3.1). Cartilage defects were found all over the joint surfaces, none of the five regions was more often affected than the others. Least osteophytes were found on the medial border of the facet joints. In conclusion, the prevalence of cervical facet joint degeneration is probably very high in individuals aged 50 years and more, with a tendency to increase in severity with age. All levels of the middle and lower cervical spine were affected to almost the same degree, whereas in the lumbar spine an increase in degeneration towards the lower levels was reported. Also, in the cervical spine in most cases the cartilage was evenly degenerated all over the joint surface while in the lumbar spine certain regions were reported to be affected predominantly.     

Prevalence of facet joint degeneration in association with intervertebral joint degeneration in a sample of organ donors

Among the most common causes of low back pain are strain on the muscles and ligaments associated with the spine, degeneration of the intervertebral discs (IVDs), and osteoarthritis of the facet joints. It is not clear, however, how these latter two conditions are related to each other in terms of their development during a patient's lifetime. The facet joint is the sole synovial joint of the spine but because it is difficult to image its degenerative history as well as its relationship to other degenerative factors within the spine remain elusive. We compared the gross and histologic characteristics of the lumbar spine from a sample of organ donors to the integrity of their associated IVDs as assessed through magnetic resonance imaging. In our study sample, we found that facet joint degeneration was common, occurring as early as 15 years of age, while the IVD could still remain intact. Facet degeneration was more severe at the L4/5 level and progressed along with IVD degeneration with age. Because such early degenerative changes in the facet joint are somewhat surprising, degeneration of this joint should not be overlooked when assessing OA of the spine and causes of lower back pain. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 29: 1267–1274, 2011     

急性颈椎间盘突出症2例误诊分析

急性颈椎间盘突出症２例误诊分析宋丽华１朱宾２李丹１１内蒙电管局中心医院神经科２放射科０１４０３０内蒙包头市青山区收稿日期：１９９５－１－２６修回日期：１９９５－０３－２０例１，男，５７岁。入院前１ｈ突感头晕，继由１ｍ高处摔下，头部着地，当即昏迷。约３...     

椎间盘退变和关节突关节骨性关节炎对腰椎稳定性的影响

目的 探讨腰椎退变过程中，腰椎间盘退变、关节突关节骨性关节炎与腰椎稳定性之间的关系。方法 对78名腰椎退变患者进行腰椎MRI和动力位X线摄影。腰椎不稳分为椎间角度运动不稳、旋转不稳和椎间位移不稳，其中椎间位移不稳细分为：前向不稳、后向不稳和前后向不稳。腰椎间盘退变依据矢状位T2加权像分为5级；关节突关节骨性关节炎依据水平位T1加权像分为4级。对资料进行统计分析。结果 腰椎椎间角度运动不稳和前后向椎间位移不稳与关节突关节骨性关节炎存在显著负相关，前向椎间位移不稳与腰椎关节突关节骨性关节炎和椎间盘退变呈显著正相关，腰椎矢状面旋转不稳与腰椎关节突关节骨性关节炎无显著相关。结论 腰椎间盘退变和腰椎关节突关节骨性关节炎可影响腰椎运动节段的稳定性。     

颈椎间盘突出症：附89例临床分析

报告８９例颈椎间盘突出症（急性５８例，慢性３１例）。重点就本症的诊断及与颈椎病的鉴别诊断进行了分析。急性颈椎间盘突出症以发病中有明确颈部外伤史、受伤当时出现急性颈脊髓／神经根损害表现、 Ｘ线片无颈椎骨折脱位及椎管狭窄，无椎管内韧带骨化等为特征；慢性颈椎间盘突出症则以发病年龄较轻（平均３６．８岁），病情发展较快，Ｘ线片无椎间关节退行性改变，椎间盘突出多为１～２个间隙等特点而不同于颈椎病．     

The relationship between facet joint osteoarthritis and disc degeneration of the lumbar spine: an MRI study

The role of MRI in assessing facet joint osteoarthritis is unclear. By developing a grading system for severity of facet joint osteoarthritis on MRI, the relationship between disc degeneration and facet joint osteoarthritis was determined. The accuracy of MRI in assessing facet joint osteoarthritis against CT was 94%. Under 40 years of age, the degree of disc degeneration varied among individuals. Over the age of 60, most of the discs were markedly degenerated. Under 40 years of age osteoarthritic changes in facet joints were minimal. Over the age of 60, variable degrees of facet joint osteoarthritis were observed but some facets did not show osteoarthritis. No facet joint osteoarthritis was found in the absence of disc degeneration and most facet joint osteoarthritis appeared at the intervertebral levels with advanced disc degeneration. Disc degeneration is more closely associated with aging than with facet joint osteoarthritis. The present study supports the hypothesis that “disc degeneration precedes facet joint osteoarthritis”, and also supports the concept that it may take 20 or more years to develop facet joint osteoarthritis following the onset of disc degeneration. Received: 1 March 1999 Revised: 27 May 1999 Accepted: 4 June 1999     

骨质疏松症对脊柱小关节退变的影响

骨质疏松症(OP)以骨量减少和骨的微细结构破坏为主要特征,并伴随骨质脆性增加和骨折危险性升高.由于骨的结构破坏,可引发脊柱退行性变,使椎体高度丢失应力改变及使人体成骨、破骨细胞代谢紊乱,发生脊柱尤其是腰椎小关节退变.但由骨质疏松症引起脊柱小关节退变尤其是腰椎小关节退变原因发病机制文献报道较少,目前认为骨质疏松对脊柱小关节退变与成骨,破骨细胞代谢影响,及发生椎体内微骨折,改变椎体高度及软骨下骨血供应微环境,增加小关节应力,减少其血供营养有关.     

Influence of an auxiliary facet system on intervertebral discs and adjacent facet joints

Background context

Facet supplementation stabilizes after facetectomy and undercutting laminectomy. It is indicated in degenerative spondylolisthesis with moderate disc degeneration and dynamic stenosis.

Purpose

To determine the influence of an auxiliary facet system (AFS) on the instrumented disc, adjacent levels' discs, and facet joints and to compare it with fusion.

Study design

Finite element study.

Methods

L3–L4, L4–L5, and L5–S1 were studied using a validated finite element model with prescribed displacements for an intact spine, lesion by facetectomy and undercutting laminectomy, AFS, and fusion at L4–L5. The distribution of segmental range of motion (ROM) and applied moments, von Mises stress at the annulus, and facet joint contact forces were calculated with rotations in all planes. Institutional support for implant evaluation and modeling was received by Clariance.

Results

In flexion-extension and lateral bending, fusion decreased L4–L5 ROM and increased adjacent levels' ROM. Range of motion was similarly distributed with intact lesion and AFS. In axial rotation, L4–L5 ROM represented 33% with intact, 55% after lesion, 25% with AFS, and 21% with fusion. Fusion increased annulus stress at adjacent levels in flexion-extension and lateral bending, but decreased stress at L4–L5 compared with AFS. In axial rotation, von Mises stress was similar with fusion and AFS. Facet loading increased in extension and lateral bending with fusion. It was comparable for fusion and AFS in axial rotation.

Conclusions

This study suggests that the AFS stabilizes L4–L5 in axial rotation after facetectomy and undercutting laminectomy as fusion does. This is because of the cross-link that generates an increased annulus stress in axial rotation at adjacent levels. With imposed displacements, without in vivo compensation of the hips, the solicitation at adjacent levels' discs and facet joints is higher with fusion compared with AFS. Fusion decreases intradiscal stress at the instrumented level.     

Cervical facet joint kinematics during bilateral facet dislocation

Previous biomechanical models of cervical bilateral facet dislocation (BFD) are limited to quasi-static loading or manual ligament transection. The goal of the present study was to determine the facet joint kinematics during high-speed BFD. Dislocation was simulated using ten cervical functional spinal units with muscle force replication by frontal impact of the lower vertebra, tilted posteriorly by 42.5°. Average peak rotations and anterior sliding (displacement of upper articulating facet surface along the lower), separation and compression (displacement of upper facet away from and towards the lower), and lateral shear were determined at the anterior and posterior edges of the right and left facets and statistically compared (P < 0.05). First, peak facet separation occurred, and was significantly greater at the left posterior facet edge, as compared to the anterior edges. Next, peak flexion rotation and anterior facet sliding occurred, followed by peak facet compression. The highest average facet translation peaks were 22.0 mm for anterior sliding, 7.9 mm for separation, 9.9 mm for compression and 3.6 mm for lateral shear. The highest average rotation of 63° occurred in flexion, significantly greater than all other directions. These events occurred, on average, within 0.29 s following impact. During BFD, the main sagittal motions included facet separation, flexion rotation, anterior sliding, followed by compression, however, non-sagittal motions also existed. These motions indicated that unilateral dislocation may precede bilateral dislocation.     

Chronology of disc degeneration and facet joint arthritis in lumbar spine is variable - A CT based cross-sectional study

BackgroundThe notion that disc degeneration (DD) always precedes facet joint arthritis (FJA) has held sway for many decades. However, it is not always the case. We hypothesized that DD is not always the first offender studied the prevalence of isolated DD and isolated FJA in the lumbar spine.MethodsInter-vertebral discs and bilateral facet joints of lumbar spines of 135 participants were graded. The participants were divided into one of the four categories. ‘No degeneration,’ ‘Isolated disc degeneration without facet joint arthritis,’ ‘Combined disc degeneration and facet joint arthritis,’ and ‘Isolated facet joint arthritis without disc degeneration.’ Multivariate logistic regression analysis was done to evaluate the predictive factors for spinal degeneration using FJA as a dependent variable while age, sex, BMI, smoking history, and DD as predictor variables.ResultsThe majority of participants had isolated FJA 64 (47.4%). Combined DD and FJA were noted in 32 (23.7%), isolated DD in 8 (5.9%), while 31(23%) had no degeneration. Only age was found to be significantly contributing to the prediction model in multivariate analysis.ConclusionOur study shows that spinal degeneration may begin either in the disc or in the facet joints depending upon the aetiological factors. It is a vicious circle that may be entered at any point, FJA or DD.     

Types of synovial fold in the cervical facet joint

Few detailed studies of synovial folds of cervical facet joints exist at the moment. This study was performed to provide anatomical data for each synovial fold in the cervical facet joints, using 20 cervical spines from C2 to C7 for dissection. Anatomic evaluation of the synovial folds included the gross morphology, in three dimensions, and the histology. Also, degenerative changes of the lower facet surface on which synovial folds occurred were evaluated. On the basis of gross morphology and histological composition, three types of synovial folds were identified. Type-1 synovial folds, shaped like a crescent, consisted principally of adipose tissue. Type-2 synovial folds had an apical region made up of dense fibrous tissue, with the base and middle region consisting of adipose tissue. In type-2 folds, the size and shape varied, including some elliptic-shaped synovial folds projecting well into the joint cavity. Type-3 synovial folds were thin with ragged free borders, and were formed exclusively of fibrous tissue. This study shows the variable appearance of synovial folds. Speculation was raised that the articular facet impingement of a large synovial fold and the subluxation of a smaller structure may play a possible role in the pathology of some disorders of the neck. Received: September 30, 1999 / Accepted: March 13, 2000     

Calcitonin gene-related peptide immunoreactive sensory DRG neurons innervating the cervical facet joints in rats

The rat C5/6 facet joint is innervated multisegmentally from the C3 to the T3 dorsal root ganglia. Sensory fibers from the C3, C4, and C7-T3 dorsal root ganglia were reported to be innervated nonsegmentally through the paravertebral sympathetic trunks, while those from the C5 and C6 dorsal root ganglia were reported to segmentally innervate the C5/6 facet joint. The presence of calcitonin gene-related peptide-immunoreactive nerve fibers has been proved in the facet joints, but their ratios have not been studied. Fluoro-gold-labeled neurons innervating the C5/6 facet joint were distributed throughout the dorsal root ganglia from the C3 to T3 levels. Of the fluoro-gold-labeled neurons, the ratios of calcitonin gene-related peptide-immunoreactive C3, C4, C45 C6, C7, C8, T1, T2, and T3 dorsal root ganglion neurons were 30%, 22%, 43%, 47%, 21%, 19%, 25%, 36%, and 40%, respectively. The ratios of calcitonin gene-related peptide-immunoreactive neurons in the C5 and C6 dorsal root ganglia were significantly higher than those in the C3, C4, C7, and C8 dorsal root ganglia. In the physiological condition in rats, the neurons of the C5 and C6 dorsal root ganglia may have a more significant role in pain sensation of the facets than other dorsal root ganglion neurons. Received: September 19, 2001 / Accepted: November 28, 2001     

单节段人工颈椎间盘置换术后小关节退变的长期临床研究

【摘要】 目的：分析人工颈椎间盘置换（artificial cervical disc replacement,ACDR）术后颈椎小关节退变的危险因素,评价其对颈椎节段运动和临床疗效的影响。方法：回顾性分析我科2003年1月~2008年1月行单节段Bryan人工颈椎间盘ACDR术的颈椎退行性疾病患者70例,其中男性43例,女性27例;术后随访时间129±14（105~165）个月;年龄55.7±8.4（37~76）岁。术前、术后及末次随访时通过颈椎动力位X线片测量手术节段活动度和颈椎整体活动度;术前、末次随访时通过CT影像根据颈椎小关节定量评分系统评估颈椎小关节退变程度。术前及末次随访同时进行日本骨科协会（Japanese Orthopaedic Association,JOA）评分及颈椎功能障碍指数量表（neck disability index,NDI）评估患者临床症状,在末次随访时进行Odom标准评价分级和颈痛的视觉模拟评分（visual analogue scale,VAS）。结果：术前小关节无或轻度退变患者41例,中度退变患者28例,重度退变患者1例;末次随访时,小关节轻度退变患者16例,中度患者退变35例,重度关节退变患者19例。通过斯皮尔曼双变量相关性检验发现小关节退变与性别、年龄有相关性。高龄、男性是小关节退变增加的危险因素,手术节段与小关节退变程度无相关性。患者术前和末次随访时手术节段活动度不存在统计学差异（9.7°±4.5° vs 8.7°±5.4°,P>0.05）,术前和末次随访时颈椎整体活动度不存在统计学差异（46.5°±15.2° vs 46.1°±13.0°,P>0.05）。患者术前及末次随访时小关节退变评分具有统计学差异（1.5±0.8分 vs 2.6±1.2分,P<0.05）;术前与末次随访时JOA评分具有统计学差异（13.5±1.9分 vs 16.5±1.4分,P<0.05）;术前与末次随访时NDI存在统计学差异（0.27±0.08 vs 0.16±0.10,P<0.05）。末次随访时Odom分级为优秀的有35例患者,为良好的有29例,为尚可的有6例,没有分级为差的患者,末次随访时VAS评分为3.47±1.55分。ACDR术后末次随访小关节退变程度与手术节段活动度呈负相关（r=-0.392,P=0.001）,与整体活动度也呈负相关（r=-0.388,P=0.001）,与JOA评分、NDI、Odom分级、VAS评分无显著性相关（P>0.05）。结论：高龄和男性是ACDR术后小关节退变的危险因素,小关节的退变程度与患者术后的颈椎活动度存在负相关,小关节退变程度与临床症状的缓解程度无关。     

Disc degeneration of cervical spine on MRI in patients with lumbar disc herniation: comparison study with asymptomatic volunteers

An association between progression of cervical disc degeneration and that of lumbar disc degeneration has been considered to exist. To date, however, this association has not yet been adequately studied. Age-related changes in the cervical intervertebral discs were evaluated by magnetic resonance imaging (MRI) in patients with lumbar disc herniation, and compared with the MRI findings of healthy volunteers without lower back pain. The purpose of this study was to clarify whether the prevalence of asymptomatic cervical disc degeneration is higher in patients with lumbar disc herniation than in healthy volunteers. The study was conducted on 51 patients who were diagnosed as having lumbar disc herniation and underwent cervical spine MRI. The patients consisted of 34 males and 17 females ranging in age from 21–83 years (mean 46.9 ± 14.5 years) at the time of the study. The control group was composed of 113 healthy volunteers (70 males and 43 females) aged 24–77 years (mean 48.9 ± 14.7 years), without neck pain or low back pain. The percentage of subjects with degenerative changes in the cervical discs was 98.0% in the lumbar disc herniation group and 88.5% in the control group (p = 0.034). The presence of lumbar disc herniation was associated significantly with decrease in signal intensity of intervertebral disc and posterior disc protrusion in the cervical spine. None of the MRI findings was significantly associated with the gender, smoking, sports activities, or BMI. As compared to healthy volunteers, patients with lumbar disc herniation showed a higher prevalence of decrease in signal intensity of intervertebral disc and posterior disc protrusion on MRI of the cervical spine. The result of this study suggests that disc degeneration appears to be a systemic phenomenon.     

Early histologic changes in lower lumbar discs and facet joints and their correlation

Biomechanical and histologic studies have highlighted the close functional relationship between lumbar discs and their associated facet joints, and it is conceivable that their degenerative changes are interdependent. However, separation of cause from effect remains controversial. Hitherto, no study in humans has correlated the changes histologically. The present study assessed histologic changes in lower lumbar discs and their associated facet joints in patients under the age of 40 years using classification systems developed for this investigation. A specific objective was to correlate changes in discs and facet joints. Data from 15 lower lumbar spine specimens were obtained. Three parasagittal sections per disc and one section per facet joint were graded histologically. The results were correlated with age, within the functional spinal unit (FSU), and with the adjacent level. Histologic changes were found in discs and facet joints from all FSUs. There was no correlation between the age of the subject and the degree of degeneration of the disc or facet joints at either level. The extent of disc degeneration at L4/5 correlated significantly with changes at L5/S1 (P < 0.01). There was no correlation between changes in discs and the associated facet joints at either level. The results of the study showed that microscopic changes are seen in the disc and facet joints from an early age and can be quite marked in some individuals before the age of 40 years. A correlation of degenerative changes within the FSU could not be established. Received: 24 February 1999 /Revised: 1 September 1999 /Accepted: 16 September 1999     

角度人工颈椎间盘置换对关节突应力的影响

目的探讨带角度人工颈椎间盘置换后关节突及相邻关节突应力变化。方法选择400名西北地区40岁以上人群颈椎侧位X线片,计算机辅助设计软件测量颈椎间盘角,设计10°人工颈椎间盘;对已建立的C4、C5两节段带椎间盘的正常颈椎有限元模型、C4、5置换0°椎间盘假体和置换10°椎间盘假体后的颈椎模型进行轴向加压、前屈/后伸、侧弯、扭转加载,对比观察C4、5关节突应力变化;对已建立的C4～C6三节段带椎间盘的正常颈椎有限元模型、C4、5置换0°椎间盘假体和置换10°椎间盘假体后的颈椎模型同样方式进行加载,对比置换节段及相邻节段的关节突应力变化。结果 C3～C7椎间盘角分别为:C3、4(9.97±3.64)°,C4、5(9.95±4.34)°,C5、6(8.59±3.75)°,C6、7(8.49±3.39)°,各椎间隙之间椎间盘角两两比较,C3、4与C4、5,C5、6与C6、7差异无统计学意义(P>0.05),其余各椎间隙之间差异均有统计学意义(P<0.05)。C4、C5两节段模型加载中,轴向加载下三者等效剪应力(Se)无明显差异;前屈/后伸时正常模型Se最大,10°假体置换组最小;侧弯时正常椎体Se最大,10°假体置换组最小;扭转时10°假体置换组更接近正常椎体生理状态力学特性。C4～C6三节段模型加载中,C4、5节段的关节突关节Se在轴向加载、前屈/后伸、侧弯时较正常椎体明显减小;扭转时减小不明显,接近正常状态。相邻下位节段C5、6关节突应力在轴向加载和侧弯时应力明显减小,扭转时应力减小较少,前屈/后伸时无明显改变,接近正常节段力学特性。结论 10°椎间盘假体植入椎间隙对颈椎相邻节段的关节突应力影响小,接近正常颈椎间盘力学性能。