颈椎间盘突出程度与颈椎X线片相关指标测量值的相关性研究

目的探讨单节段脊髓型颈椎病患者颈椎X线片相关指标与椎间盘突出导致的颈脊髓压迫严重程度的相关性。方法回顾性分析2012年8月—2014年3月安徽医科大学第一附属医院脊柱外科诊治的60例单节段脊髓型颈椎病患者的临床资料,均为男性,年龄42~65岁,平均(54.8依9.3)岁。在颈椎MRI矢状位成像上按照颈脊髓受压的比例( E值)分为Ⅰ组、Ⅱ组及Ⅲ组。在颈椎MRI横断面成像上测量并计算颈髓横切面积( S1)与有效椎管横切面积( S0)的比值,以此判断椎间盘突出程度;在不同体位颈椎X线摄片上测量责任椎间隙的活动度值(B值)、椎间隙前缘高度( D值)、颈椎C2~7 Cobb角及椎间孔面积( M值)等相关指标。采用直线相关回归分析颈椎间盘突出程度与各观测指标之间的相关性。结果3组间S1/S0值、E值、B值、D值、C2~7 Cobb角和M值差异均有统计学意义(F值分别为44.187、112.789、7.232、3.778、3.232、15.813,P值均<0.05)。随着S1/S0值的增加,E值、B值、D值、C2~7 Cobb角和M值均逐渐减小,提示责任椎间隙E值、B值、D值、C2~7 Cobb角、M 值与 S1/S0值均呈负相关性( R 值分别为-0.821、-0.581、-0.378、-0.419、-0.576,P值均<0.05)。经多元线性回归分析,B 值、D 值、M 值是 S1/S0的3个独立影响因素, S1/S0值的预测方程为^Y=118.955-1.348X1-2.850X2-0.541X3(复相关系数R=0.742,决定系数R2=0.550,F=22.841,P<0.01),回归模型有统计学意义。结论不同体位颈椎X线摄片的相关指标B值、D值、M值是影响脊髓型颈椎病椎间盘退变突出程度的独立因素,对评估单节段脊髓型颈椎间盘突出的严重程度有一定的诊断价值;采用D值、B值及M值为3个自变量指标,可对椎间盘突出进行预测。     

Effect of osteoporosis and intervertebral disc degeneration on endplate cartilage injury in rats

Objective:To investigate the effect of osteoporosis and intervertebral disc degeneration on the endplate cartilage injury in rats.Methods:A total of 48 female Sprague Dawley rats(3 months)were randomly divided into Groups A,B,C and D with 12 rats in each group.Osteoporosis and intervertebral disc degeneration composite model,simple degeneration model and simple osteoporosis model were prepared in Groups A,B and C respectively.After modeling,four rats of each group at 12th.18th and 24th week were sacrificed,Intervertebral height of cervical vertebra C6/C7 was measured.Micro-CT was used to image the endplate of cephalic and caudal cartilage at C6/C7 intervertebral disc.Abraded area rate of C6 caudal and C7 cephalic cartilage endplate was calculated,and then C6/C7 intervertebral disc was routinely embedded and sectioned.stained with safranin O to observe histological changes microscopically.Results:At 12,18 and24 weeks,intervertebral disc height of C6/C7 were(0.58±0.09)mm,(0.53±0.04)mm and(0.04±0.06)mm in Group A rats,(0.55±0.05)mm,(0.52±0.07)mm and(0.07±0.05)mm in Group B rats.At 24th week.intervertebral disc height of Group A rats was significantly lower than that of Group B rats(P0.05);intervertebral disc height of Groups A and B rats at each time point were significantly lower than that of Groups C and D(P0.05).There was no significantly statistical difference of intervertebral disc height between Groups C and D(P0.05).At 12 and 18 weeks,the abraded rate of C6 caudal and C7 cephalic cartilage endplate in Group A rats were significantly higher than that in Groups B.C and D rats(P0.05);the abraded rate in Group B was significantly higher than that in Groups C and D(P0.05).Microscopic observation of CT showed that ventral defects in C6caudal or C7 cephalic cartilage endplate in Groups A and B appeared after 12 weeks of modeling;obvious cracks were found in front of the C6 and C7 vertebral body,and cartilage defect shown the trend of"repairing"at 18 and 24 weeks after modeling.Conclusions:Intervertebral disc degeneration and osteoporosis can cause damage to the cartilage endplate.Co-existence of these two factors can induce more serious damage to the endplate.which has possitive correlation with intervertebral disc degeneration.Osteoporosis plays a certain role in intervertebral disc degeneration process,and accelerates the degeneration of intervertebral disc in a specific time window.     

Expression of soluble Fas and soluble FasL in human nucleus pulposus cells

The study aimed for addressing the expression of soluble Fas (sFas) and soluble Fas Ligand (sFasL) in human nucleus pulposus (NP) and its attendant relationship with disc degeneration. Human NP samples were collected from patients with disc degeneration and cadavers as degenerate and normal groups, respectively. Subsequently, NP cells were cultured in monolayer. ELISA was performed to identify the expression levels of sFas and sFasL in the supernatant of NP cell cultures in vitro. Quantitative real-time PCR was used to detect the expression of sFas and sFasL in human NP cells in mRNA solution. The study comprised 12 degenerate and 8 normal cadaveric NP samples. The concentration value of sFas in the supernatant was significantly higher from degenerate NP than that from normal NP at each time point. In contrast, sFasL was significantly lower at each time point. Moreover, the expression of sFas and sFasL reached the peak at various early stages of cell cultures and decreased thereafter. Furthermore, the mRNA level of Fas in degenerate NP cells was significantly higher than that in normal cells; whereas FasL showed an opposite pattern. The study is the first addressing the expression of sFas and sFasL in human NP cell cultures. Moreover, the expression of sFas and sFasL varies with culture time in vitro with different levels in degenerate and normal settings. These findings indicate that sFas and sFasL might play a role in intervertebral disc degeneration.     

Finite Element Modeling of Stress Distribution in Intervertebral Spacers of Different Surface Geometries

Intervertebral disc spacers using bioactive ceramics have been used to treat degenerative spinal disease. Tooth‐shaped spacers are commonly used to prevent migration, but there is a possibility of fracture when inserted or after insertion. Intervertebral disc spacers with either an isosceles triangle‐shaped tooth (T1) or a right triangle‐shaped tooth (T2) were used as a control group. The design factors for the experimental group were modified to prevent fractures induced by stress concentration, and the surfaces of the spacers were designed as either an isosceles triangle‐shaped valley (V1) or a right triangle‐shaped valley (V2). Linear analysis using finite element model (FEM) was performed, and Von Mises stress distribution was calculated by applying 1000 N of uniformly distributed load. Samples of the V2 design were made with bioactive glass‐ceramics (BGS‐7) and evaluated for compressive strength, fatigue degree, and impact strength. Von Mises stress was highest at the first tooth from the posterior side for the control group and at the center for the experimental group. Compared with the control group, the experimental group showed 18.4% and 82.5% reduction (V1 vs. T1 and V2 vs. T2, respectively) in the maximum stress at the bottom of the valleys. The FEM analysis revealed that the V2 design had the most even load distribution. The V2 samples with bioactive glass‐ceramics were evaluated for compressive strength, and all six samples were not fractured up to 24 000 N. However, the average impact strength was 19.42 kN, suggesting that momentary force caused damage at a lower load than compression with a steady speed. The BGS‐7 intervertebral disc spacer with V2 design was not fractured during the fatigue test at maximum pressure of 8000 N, R ≥10, 5 Hz, and 5 million cycles. These data confirm that the BGS‐7 spacer with the V2 design may be clinically applicable. Collectively, the modified surface geometry of the experimental group significantly lowered Von Mises stress values at the bottom of the valleys, and thus the possibility of fracture by compressive load was greatly reduced. Also, impact during insertion was confirmed to cause fracture more easily, as the impact strength was lower than the compressive strength in the experimental group.     

Construction of a Tissue‐Engineered Annulus Fibrosus

The intervertebral disc is composed of load‐bearing fibrocartilage that may be subjected to compressive forces up to 10 times the body weight. The multilaminated outer layer, the annulus fibrosus (AF), is vulnerable to damage and its regenerative potential is limited, sometimes leading to nuclear herniation. Scaffold‐based tissue engineering of AF using stem cell technology has enabled the development of bi‐laminate constructs after 10 weeks of culture. It is difficult to know if these constructs are limited by the differentiation state of the stem cells or the culture system. In this study, we have characterized an expandable scaffold‐free neoconstruct using autologous AF cells. The construct was prepared from pellet cultures derived from monolayer cultures of AF cells from mature pigs that became embedded in their own extracellular matrix. The pellet cultures were incubated for 24 h in a standardized conical tube and then carefully transferred intact to a culture flask and incubated for 21 days to allow continued matrix synthesis. Cell viability was maintained above 90% throughout the culture period. The engineered scaffold‐free construct was compared with the native AF tissue by characterization of gene expression of representative markers, histological architecture, and biochemical composition. The morphological and biochemical characteristics of the cultured disc construct are very similar to that of native AF. The cell number per gram of construct was equal to that of native AF. Expression of aggrecan was elevated in the engineered construct compared with RNA extracted from the AF. The glycosaminoglycan content in the engineered construct showed no significant difference to that from native construct. These data indicate that scaffold‐free tissue constructs prepared from AF cells using a pellet‐culture format may be useful for in vitro expansion for transplantation into damaged discs.     

改良腰椎板截骨回植治疗失稳性腰椎间盘突出症

目的：评价改良腰椎板截骨回植在失稳性腰椎间盘突出症中的疗效。方法：2009年3月至2011年8月对63例失稳性腰椎间盘突出症的患者行髓核摘除＋椎间融合＋椎弓根螺钉内固定＋改良腰椎板截骨回植手术,男33例,女30例;年龄22～68岁,平均48．4岁;病程3个月～13年,平均38．8个月。患者均有不同程度的腰腿疼痛,x线片、CT及MR检查诊断为失稳性腰椎间盘突出症。观测手术前后ODI和JOA评分、并发症发生率、影像学回植椎板愈合率及腰腿痛复发率。结果：62例患者切口I期愈合,1例11期愈合,无下肢深静脉血栓及椎间隙感染等并发症出现。61倒获1年或以上随访,平均随访时间33个月。术中神经损伤发生2例,硬膜囊损伤发生1例;术后1年回植椎板愈合58例：腰痛复发4例,腿痛复发1例。术后2周、6、12个月的ODI及JOA评分显著优于术前（P〈0．05）。结论：改良椎板截骨回植术治疗失稳性腰椎间盘突出症具有较低的术中神经硬膜囊损伤率和腰腿痛复发率、较高的椎板愈合率和较好的临床评分,是一种安全、有效的新方法,为临床失稳性腰椎间盘突出症手术开辟了一种新的术式。     

微创下腰椎经椎间孔椎体间融合术混合内固定治疗复发性腰椎间盘突出症的可行性研究

目的 探讨微创腰椎经椎间孔椎体间融合术(MIS-TLIF)采用椎弓根螺钉结合对侧经椎板关节突螺钉混合内固定治疗复发性腰椎间盘突出症的可行性.方法 选取2010年1月至2011年12月符合纳入排除标准的16例复发性腰椎间盘突出症患者资料进行回顾性研究.其中男性10例,女性6例,年龄35 ～ 68岁,平均45岁.采用单侧切口工作通道下完成MIS-TLIF手术,在完成椎管减压、椎体间融合和单侧椎弓根螺钉内固定后,同一切口经棘突根部向对侧置入经椎板关节突螺钉,进行围手术期指标观察、影像学和疗效评价.视觉模拟量表(VAS)评分和Oswestry功能障碍指数(ODI)评分的比较采用重复测量方差分析.结果 所有患者均在工作通道下顺利完成椎管内减压、椎体间融合和混合内固定,无患者出现神经症状.平均手术时间(148±75) min,术中出血量(186±226) ml,术后平均下床活动时间(32±15)h,平均住院日(6±4)d,手术切口长度平均(29±4) mm,经椎板关节突螺钉平均长度(52 ±6) mm.患者术后随访12 ～ 24个月,平均16.5个月.术后X线和CT显示混合内固定位置良好,经棘突椎板关节突螺钉均穿过椎板和关节突关节,术后随访期间腰痛和腿痛VAS与ODI评分与术前相比较均明显改善,差异有统计学意义(腰痛VAS:F=52.845,P=0.000;腿痛VAS:F=113.480,P=0.000; ODI评分:F=36.665,P=0.000).结论 单侧切口MIS-TLIF采用混合内固定可治疗复发性腰椎间盘突出症,具有创伤小、恢复快等优点.     

High glucose-induced oxidative stress promotes autophagy through mitochondrial damage in rat notochordal cells

Purpose

Diabetes mellitus is associated with an increased risk of intervertebral disc degeneration (IDD). Reactive oxygen species (ROS), oxidative stressors, play a key role in autophagy of diabetes-associated diseases. Mitochondria are known to be the main source of endogenous ROS in most mammalian cell types. The authors therefore conducted the following study to evaluate the effects of high glucose concentrations on the induction of oxidative stress and autophagy through mitochondrial damage in rat notochordal cells.

Methods

Rat notochordal cells were isolated, cultured, and placed in either 10 % fetal bovine serum (normal control) or 10 % fetal bovine serum plus two different high glucose concentrations (0.1 M and 0.2 M) (experimental conditions) for one and three days, respectively. We identified and quantified the mitochondrial damage (mitochondrial transmembrane potential) and the generation of ROS and antioxidants (manganese superoxide dismutase [MnSOD] and catalase). We also investigated expressions and activities of autophagy markers (beclin-1, light chain3-I [LC3-I] and LC3-II, autophagy-related gene [Atg] 3, 5, 7, and 12).

Results

An enhanced disruption of mitochondrial transmembrane potential, which indicates mitochondrial damage, was identified in rat notochordal cells treated with both high glucose concentrations. Both high glucose concentrations increased production of ROS by rat notochordal cells in a dose- and time-dependent manner. The two high glucose solutions also enhanced rat notochordal cells’ compensatory expressions of MnSOD and catalase in a dose- and time-dependent manner. The proautophagic effects of high glucose concentrations were manifested in the form of enhanced rat notochordal cells’ expressions of beclin-1, LC3-II, Atg3, 5, 7, and 12 in a dose- and time-dependent manner. The ratio of LC3-II/LC3-I expression was also increased in a dose- and time-dependent manner.

Conclusions

The findings from this study demonstrate that high glucose-induced oxidative stress promotes autophagy through mitochondrial damage of rat notochordal cells in a dose- and time-dependent manner. These results suggest that preventing the generation of oxidative stress might be a novel therapeutic target by which to prevent or to delay IDD in patients with diabetes mellitus.     

Spotlight通道系统与显微内窥镜椎间盘切除术治疗腰椎椎间盘突出症临床对比

目的比较Spotlight通道系统和显微内窥镜椎间盘切除术(microendoscopic discectomy,MED)技术治疗腰椎间盘突出症的临床应用特点及疗效。方法 2011年3月～2012年3月收治的椎间盘突出症选择微创治疗患者40例,其中男26例,女14例;年龄26～58岁,平均41.7岁。患者随机分入Spotlight通道系统和MED技术治疗组,2组患者基本资料经统计学分析差异无统计学意义。对2组患者手术时间、术中出血量、手术切除的骨与韧带组织量、平均住院时间、并发症发生情况以及手术前、术后6个月随访时腰腿痛视觉模拟量表(visual analog scale,VAS)评分、Oswestry功能障碍指数(Oswestry disability index,ODI)进行对比分析。结果 2组患者均获得随访。Spotlight组和MED组的手术时间分别为(53.2±11.4)min和(78.1±12.5)min,差异有统计学意义(P<0.05);2组术中出血量、切除的骨与韧带量、平均住院时间、并发症发生情况的差异无统计学意义(P>0.05)。同组术后6个月VAS评分、ODI与术前相比明显改善(P<0.05);手术前后2组之间的差异无统计学意义(P>0.05)。结论 Spotlight通道系统是"直视下的微创"手术方式之一,具有与MED近似的临床疗效,且其由于操作灵活具有更为广泛的适应证,更易为脊柱外科医师所掌握。