骨质疏松绵羊腰椎内不同椎弓根螺钉界面的组织学研究

目的通过硬组织切片及染色技术观察骨质疏松绵羊腰椎内膨胀式椎弓根螺钉(expansive pedicle screw,EPS)与骨水泥强化螺钉(polymethylmethacrylate-augmented pedicle screw,PMMA-PS)的钉道界面。方法建立骨质疏松绵羊后将每只绵羊的腰椎(L1~6)随机分入三个不同的置钉组。使用相同的方法制备钉道后,普通椎弓根螺钉(CPS)组:经椎弓根向椎体内拧入CPS;PMMA-PS组:向制备好的钉道内注入1.0 m L的PMMA后拧入CPS;EPS组:直接经椎弓根向椎体内拧入EPS。术后6周和12周处死绵羊,经硬组织切片及染色后行组织学观察。结果组织学观察表明,在术后6周和12周,CPS组和EPS组中骨小梁直接与螺钉接触,形成了"螺钉-骨质"界面。PMMA-PS组中PMMA包裹螺钉,阻碍了螺钉与骨小梁的直接接触,形成了"螺钉-PMMA-骨质"界面,EPS组螺钉的前端明显膨胀形成了一个"爪状"结构,挤压并显著改善了局部的骨质条件。从术后6周到12周,CPS组和PMMA-PS组中螺钉周围的骨质条件无明显变化,PMMA无明显降解吸收,PMMA组中形成了二次界面,然而,术后12周EPS前端周围的骨质情况和钉道界面均明显优于术后6周。结论在骨质疏松绵羊腰椎内,术后早期EPS通过螺钉前段的膨胀挤压刺激周围骨小梁生长,显著改善了周围的骨质基础,随着螺钉膨胀部分持续挤压的刺激,螺钉前段周围的骨质条件在远期有进一步的显著改善,形成了良好的生物性界面,为螺钉的远期稳定提供了良好的骨质条件。     

经后路PLIF加BIOFLEX治疗腰椎失稳症

目的 探讨经后路植入椎体间可撑开螺文融合器PLIF及弹性椎弓根内固定系统BIOFLEX对腰椎失稳定症治疗的临床效果.方法 对132例腰椎失稳症患者采用后路椎管及神经根管减压,BIOFLEX椎弓根系统固定并椎间植入PLIF手术治疗.结果 132例术后随访8～23个月,平均15个月,未发现椎间植骨不融合情总,术后优良率97.7%.结论 经后路植入椎体间传统椎间融合术的许多不足,大大减少了术后并发症,提高了腰椎失稳症的治疗效果.     

经椎弓根内固定的形态与生物力学研究

目的：提高临床医师对椎弓根内固定技术的理论认识。方法：应用直径４．５ｍｍ,５．５ｍｍ,６．２５ｍｍ和７．０ｍｍ４种不同直径的椎弓根螺钉１６具Ｔ６～Ｓ１节段的新鲜尸体脊柱标本上观察：（１）穿钉失败率;（２）椎弓根膨胀变形率;（３）椎弓根螺钉把持力;（４）椎弓根椎体损伤分类。结果：穿钉失败率与操作技术和椎弓根横径相关,在下胸椎失败率高主要与椎弓根横径密切相关,没有发生穿钉失败的椎弓根膨胀率２８．６％～     

椎弓根劈裂对内固定稳定性影响的生物力学研究

目的探讨椎弓根螺钉内固定时椎弓根皮质劈裂对骨折椎体稳定性的影响。方法取新鲜成年羊胸腰椎脊柱标本(T14~L2)20具,随机分为A、B两组。在A组和B组标本的L1椎体上分别制作单椎体压缩骨折模型,再单独对B组标本T14胸椎任意一侧的椎弓根行外侧(1/4~1/2)切除,作为椎弓根劈裂椎体骨折模型。然后对A、B两组分别置钉,进钉深度为钉道全长。标本模型固定后,在HY-3080微机控制电子万能材料试验机上,以频率为1.5 Hz的载荷对两组标本模型行10 000次疲劳实验,分别测量疲劳实验后两组标本前屈、后伸、左侧弯、右侧弯4个方向运动范围的大小和疲劳实验后两组标本模型螺钉拔出力大小,并比较两组差异。结果疲劳实验后A组各个方向活动范围:前屈(1.81±0.14)mm,后伸(1.68±0.37)mm,左侧弯(4.08±0.41)mm,右侧弯(4.18±0.12)mm;B组各个方向活动范围大小:前屈(4.49±0.40)mm,后伸(3.72±0.51)mm,左侧弯(6.67±0.64)mm,右侧弯(6.73±0.58)mm;A组各个方向活动范围均小于B组(P0.01)。疲劳实验后A组螺钉最大拔出力为(252.34±51.27)N,B组螺钉最大拔出力为(115.50±36.74)N,最大拔出力A组大于B组(P0.01)。结论椎弓根皮质劈裂将严重影响骨折椎体内固定的稳定性。     

不同矢状角度置入椎弓根螺钉的拔钉生物力学研究

目的 观察椎弓根螺钉不同矢状成角置入后单个椎体的拔钉生物力学特点,为临床置钉提供理论依据.方法 采用猪新鲜L1共12个椎体标本,将24侧椎弓根分三组,按不同矢状成角0°组、10°组、-20°组置人椎弓根螺钉,测出最大轴向拔出力.结果 -20°组椎弓根螺钉拔出力及拔出能量最大,0°组最小,10°组界于二者之间;三组之间最大拔出力及拔出能量两两比较P＜0.05.提示各组之间差异均有统计学意义.结论 矢状面成角置钉对螺钉的把持力大于0°角置钉,随置钉角度的增加,螺钉把持力也增大.     

两种不同方法提高椎弓根螺钉稳定性的体外生物力学研究

目的 比较膨胀式椎弓根螺钉(EPS)与骨水泥(PMMA)强化方法在体外提高螺钉稳定性的效果.方法 将60个新鲜成年绵羊腰椎随机分为三组.普通椎弓根螺钉组(CPS组):直接拧入普通椎弓根螺钉;PMMA-PS组:向钉道内注入PMMA(1.0 ml)后拧入CPS;EPS组:直接拧入EPS.24 h后对所有标本进行X线检查,随...     

椎弓根螺钉内固定治疗中上胸椎骨折的临床研究

目的探讨应用椎弓根螺钉内固定治疗不稳定中上胸椎骨折的安全性和可行性。方法2001年3月~2005年1月,采用椎弓根螺钉内固定治疗不稳定中上胸椎骨折21例,其中GSS固定15例,USS固定6例。结果21例均获随访,随访时间10~42个月,平均22·3个月,伤椎前缘高度由术前平均40%恢复至术后91%,术后CT示螺钉位置不良9枚,其中Ⅰ级6枚,Ⅱ级2枚,Ⅲ级1枚,术后无神经系统症状加重,无脑脊液漏。结论胸椎椎弓根螺钉固定治疗不稳定中上胸椎骨折可获得满意的复位,中上胸椎椎弓根螺钉固定有一定风险,根据术前脊柱正侧位X线片和CT片,正确选择螺钉直径及进针点、角度和深度及进钉方向,胸椎椎弓根螺钉在中上胸椎骨折中的应用是安全的。     

DFRS椎弓根钉钢板系统在腰椎滑脱症中的应用

目的：研究DFRS椎弓根钉钢板系统在腰椎滑脱症中的应用，方法：应用DFRS椎弓根钉钢板系统，治疗腰椎滑脱46例。结果：术后随访1－3年，41例完全复位，复位率89％，术后41例患者患肢疼痛症状消失。结论：DFRS，设计合理，操作比较简单，采用钛合金，不影响以后CT、MRI检查，手术复位效果好，符合生理需要，临床效果满意，其不失为一种即经济又方便的治疗技术。     

后外侧融合椎弓根螺钉固定术在腰椎退行性疾病中的应用

目的探讨提高腰椎退行性疾病手术疗效的方法。方法对220例腰椎退行性疾病，实行腰椎间盘摘除、椎管减压、复位等常规操作的同时，进行后外侧腰椎融合和椎弓根螺钉器械固定。结果症状完全消失186例，部分缓解30例，无明显改善4例，治疗满意率98．2％。并发症总发生率为6．4％，无再手术及症状加重病例，判定融合215例，融合成功率97．7％。结论在腰椎退行性疾病手术中，应用后外侧融合和椎弓根内固定技术能获得较好的临床效果。     

C臂机导航下经皮椎弓根钉内固定联合对侧微创TLIF治疗腰椎管狭窄症

目的 探讨导航辅助下经皮椎弓根钉内固定,联合对侧微创经椎间孔椎体间融合术(Transforaminal Lumbar Interbody Fusion,TLIF),治疗腰椎管狭窄症的临床应用.方法 2010年6月至2012年6月,对47例腰椎管狭窄症患者行导航下经皮椎弓根钉内固定,联合对侧微创TLIF术治疗,观察手术时间、出血量以及手术前后的VAS和ODI评分,并将经皮钉侧和开放置钉侧进行配伍对照比较.结果 平均出血量为(420±45) mL;术前VAS评分为(6.85±1.03),术后1月VAS评分为(1.88±0.79);术前ODI评分为(31.6±3.05),术后1月ODI评分为(43.1±3.23).配伍对照研究结果显示,经皮钉组A级101枚、B级9枚、C级2枚,开放置钉组A级86枚、B级21枚、C级4枚、D级1枚.经皮钉组平均置钉时间为(11.25±4.33) min,透视次数为(2.73±0.42)次,开放置钉组平均置钉时间为(15.43±5.65) min,透视次数为(4.12±0.85)次.差异均有统计学意义.结论 导航辅助下经皮椎弓根钉内固定,联合对侧微创TLIF治疗腰椎管狭窄症疗,效果显著,导航辅助下经皮钉组置钉术的准确度优于开放置钉组,透视次数和置钉时间均少于开放组.     

双节段后路腰椎椎体间融合术单侧椎弓根钉固定的生物力学稳定性

目的 分析对模拟双节段腰椎后路椎体间融合术(PLIF)采用单侧椎弓根钉固定(单侧固定)的生物力学稳定性.方法 将6具新鲜成人尸体腰椎标本(L2～S2)分别制备成L4～S1的PLIF模型,应用MTS 858实验机模拟产生屈伸、侧弯、轴向旋转,并按初始状态、单侧不稳、单侧不稳-单侧固定、双侧不稳-单侧固定、双侧不稳-双侧固定、双侧不稳的顺序进行测试,动态摄取记录各个节段角位移运动范围(ROM)与中性区值(NZ).结果 单侧不稳-单侧固定屈伸、侧弯、轴向旋转方向ROM值依次为2.53±1.12、4.03±2.19、2.78±1.00,NZ值依次为1.14±0.70、1.96±1.13、1.28±0.71,均显著小于初始状态(P<0.05),相比双侧不稳-双侧固定,各方向ROM与NZ值分别增加60.13%与17.52%、315.46%与243.86%、8.17%与6.20%,但差异无统计学意义(P>0.05).双侧不稳-单侧固定侧弯与旋转状态ROM与NZ值较双侧不稳-双侧固定显著增加(P<0.05).结论 单侧固定对人腰椎标本模拟双节段单侧PLIF可提供与双侧固定相似的生物力学稳定性,而对于模拟双节段双侧PLIF则单侧固定在大多数三维运动方向上不能提供足够的力学稳定性.

Abstract：

Objective To analyze the biomechanical efficacy of unilateral pedicle screw fixation on human cadaveric lumbar spine model simulated by two-level posterior lumbar interbody fusion (PLIF). Methods Six fresh-frozen adult human cadaveric lumbar spine motion segments (L2-S2) were simulated to unilateral/bilateral L4-S1 PLIF constructs augmented by unilateral/bilateral pedicle screw fixation sequentially and respectively. All configurations were tested by MTS 858 in the following sequential construct order: the intact, UI (unilateral instability), UIUF1C (unilateral instability via unilateral pedicle screw fixation plus one cage) , BIUF1C (bilateral instability via unilateral pedicle screw fixation plus one cage) , BIBF1C (bilateral instability via bilateral pedicle screw fixation plus one cage) and BI (bilateral instability without pedicle screw and cage). Each specimen was nondestructively tested in flexion/extension, lateral performed between different simulated constructs with One Way of ANOVA and Post hoc LSD tests. Results BIBF1C had the lowest ROM and NZ of L4-S1 fusion segments in all loading models, which were significantly lower than those of any uninstmmented construct (the intact, UI and BI) (P < 0. 05). In flexion/extension, lateral bending, and axial rotation, the ROM of UIUF1C was respectively 2.53 ± 1. 12, 4.03 ± 2. 19, 2. 78 ±1.00 and the NZ of UIUF1C was respectively 1.14 ±0.70, 1.96 ±1. 13, 1.28 ±0.71, which were significantly lower than those of the intact (P <0. 05). Compared to BIBF1C, the ROM and NZ were respectively increased 60.13% and 17.52% in flexion/extension, 315.46% and 243.86% in lateral bending, 8. 17% and 6. 20% in axial rotation, however, there were no significant differences between these two constructs (P > 0. 05). In lateral-bending and axial rotation, the ROM and NZ of BIUF1C were significantly higher than those of BIBF1C (P < 0. 05). In flexion/extension, the ROM and NZ of BIUF1C were higher than those of BIBF1C but there were no significant differences (P >0. 05). Compared to the intact, BIUF1C had lower ROM and NZ except for higher NZ in axial rotation, and there were significant differences only in flexion/extension (P < 0. 05). Conclusions All tested two-level unilateral fixation on simulated human cadaveric model with unilateral PLIF can achieve similar initial biomechanical stability in comparison with two-level bilateral pedicle screw fixation. However in most test modes, two-level unilateral pedicle screw fixation on simulated human cadaveric model with bilateral PLIF can not achieve enough biomechanical efficacy in comparison with two-level bilateral pedicle screw fixation.     

腰椎上关节突关节面后缘与椎弓根中心关系的解剖学观察及其临床意义

目的 :探讨腰椎上关节突关节面后缘与椎弓根中心的关系。方法 :成人干燥腰椎骨 10 0套 ,对上关节突关节面的形态特点及其后缘与椎弓根中心的关系进行了观测。结果 :上关节突关节面后缘在L13 6.7% ,L2 2 7.2 % ,L32 5 .6% ,L4 7.3 % ,L52 .3 %位于椎管内或与椎弓根内侧皮质重叠 ,其切线距椎弓根中心距离 :L12 .3mm± 1.9mm ,L2 2 .9mm± 1.7mm ,L3 3 .5mm± 1.8mm ,L4 3 .7mm± 1.5mm ,L55 .4mm± 1.7mm。结论 :以上关节突关节面后缘作为椎弓根螺钉定位点的纵向标志易穿破椎弓根内侧骨皮质 ,该定位线偏内 ,是造成螺钉并发症的原因之一。     

Computed Tomography Evaluation of Percutaneous Pedicle Screws Inserted during Minimally Invasive Transforaminal Lumbar Interbody Fusion: Long-term Follow-up Results of Screw Violation

BackgroundTo evaluate the accuracy of percutaneous pedicle screw (PPS) insertion in degenerative lumbar disease treated with minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) and to analyze risk factors and long-term clinical outcomes of screw violation.MethodsSixty-two consecutive patients (262 screws) were included. Based on postoperative computed tomography (CT) axial images, a PPS that perforated out of the pedicle was classified into a violation group, while screws surrounded by pedicular cortical bone were classified into a correct group. A logistic regression model was used for risk factor analysis of violation. We also observed the long-term clinical outcomes using the Oswestry disability index and visual analog scale.ResultsOf the 262 screws, 14 (5.3%) were considered to be violated (10 medial violations and 4 lateral violations). All violations of S1 and L5 were in the medial direction. In contrast, entire violations of L4 were always lateral and of the 2 violations of L3, one was lateral and the other was medial. There were no cases of superior or inferior violation. The mean pedicle convergence angle (CA) was significantly higher in the violation group (mean ± standard deviation, 27.0° ± 6.2°) than in the correct group (21.7° ± 5.4°). There were no significant differences according to vertebral rotational angle, body mass index, bone mineral density, and surgical timing (learning curve) between the two groups. Logistic regression analyses demonstrated that a high CA was a significant risk factor for pedicle wall violation (p = 0.002). There were no significant differences in clinical or radiographic results between the two groups in 60 patients who were followed up for more than 1 year and in 40 patients who were followed up for more than 5 years. There were 2 patients who required reoperation to replace a screw due to leg pain.ConclusionsWith PPS insertion during MI-TLIF, the rate of pedicle violation was 5.3% (14/262). An understanding of the anatomical characteristics of each vertebra and the unique structures of the patient is essential to prevent pedicle violations. Even in the violation group, PPS fixation was found to be a safe and useful procedure with successful long-term radiographic and clinical outcomes.     

腰椎侧位片判断椎弓根螺钉进钉深度的放射解剖学研究

目的 :探讨用腰椎侧位片判断椎弓根螺钉进钉深度的可行性。材料和方法 :在 31套腰椎骨标本上 (310个椎弓根 )用 1mm软钢丝在椎弓根最狭窄处缠绕 ,按人字嵴顶点进针方法打入椎弓根直钢丝 ,拍正侧位片及横断面片 ,观测直钢丝在椎弓根及椎体内的位置 ,并推算进钉深度比率。结果 :腰椎侧位片上椎弓根螺钉进钉深度比率为L1(88.1±5 ) % ,L2 (86 .2± 4.4) % ,L3(87.7± 4.4) % ,L4 (87.2± 5 .1) % ,L5(88.1± 5 .1) %。结论 :在腰椎侧位片上可判定椎弓根螺钉进钉深度 ,其最佳比率L1～L5为 85 %～ 90 %。     

腰椎经椎弓根螺钉系统内固定治疗腰椎间盘突出症

目的分析使用椎弓根螺钉系统内固定治疗腰椎间盘突出症的适应证与近期临床效果。方法对222例腰椎间盘突出症患者行后路减压,经椎弓根植入椎弓根螺钉,用钉-棒联结结构固定棒杆,应用椎间融合器植骨(Cage)融合,或行横突间植骨。结果随访时间2~37个月,根据Macnab手术评价标准,优良率为98·20%。结论椎弓根螺钉系统内固定治疗腰椎间盘突出症是一种使用安全,近期随访疗效满意的方法。