下颈椎前路椎弓根螺钉植入的相关解剖学及影像学研究

目的通过测量成人下颈椎椎弓根的解剖学及CT图像相关参数,为临床应用下颈椎前路椎弓根螺钉内固定（ATPS）提供相关数据。方法成人干燥下颈椎标本24具及随机在CT室保存的34例成人患者的颈椎CT三维重建图像,测量C3-C7椎体的椎弓根宽（OPW）、椎弓根高（OPH）、椎弓根的中轴全长（PAL）、椎弓根外倾角（sPA）、椎弓根头倾角（tPA）、椎弓根投影中距（DtIP）、椎弓根投影上距（DsIP）,进行统计学分析,制定ATPS置钉参数。结果解剖学测量值与影像学测量值比较无统计学差异（P均〉0.05）。本研究提示：C3、C4进针点位于椎体正中矢状面受术椎弓根的对侧2-3 mm,距椎体上终板平面1-4 mm;C5进针点位于椎体正中矢状面受术椎弓根的同侧或对侧1-2 mm,距椎体上终板平面4-5 mm;C6、C7进针点位于椎体正中矢状面受术椎弓根的同侧3-5 mm,距椎体上终板平面5-8 mm。椎弓根中轴外倾角平均分别为C348°,C448°,C540°,C634°,C731°。椎弓根中轴头倾角平均分别为C384°,C489°,C5107°,C6114°,C7100°。置钉长度选择28、30、32、34 mm,螺钉的直径可选择3.0、3.5、4.0 mm。结论通过对下颈椎标本及成人下颈椎CT三维重建测量,并总结出进钉参数,证明下颈椎ATPS技术的可行性。     

颈椎椎弓根形态个体化术前应用CT测量评价的临床意义

目的为有效施行颈椎椎弓根固定术,临床探讨术前采用CT测量的颈椎椎弓根置钉准确度以及置钉可行性。方法选取我院2014年2月-2015年7月期间96例行颈椎椎弓根固定患者,分为手测组、CT组,按入院时间进行分配,每组48例。CT组术前采用CT测量椎弓根高度、宽度确定置钉点,手测组采用手工测量椎弓根确定置钉点,观察置钉成功率、置钉准确度,记录椎弓根测量情况以及置钉时间、出血量。结果 CT组每钉置钉时间、出血量分别为(3.78±2.45)min、(307.42±179.47)ml明显少于手测组的(4.65±2.34)min以及(367.42±165.49)ml(P0.05);CT组与手测组在椎弓根高度、椎弓根宽度的C3-C6椎弓根参数测量值比较差别无意义(P0.05);CT组置钉准确度高达95.8%,出现全穿破率仅为4.2%,手测组为85.4%,且全穿破率高达14.6%,CT组较手测组置钉准确度高(P0.05)。结论临床采用CT测量所得椎弓根参数准确度高、临床置钉准确度高,且出血量少、置钉耗时少,可为临床个体化置钉提供较为准确的数据。     

颈椎椎弓根标本与CT图像测量椎弓根相关径线结果的比较

目的:比较颈椎椎弓根标本与CT图像测量椎弓根相关径线的差异,为临床颈椎椎弓根置钉手术前CT图像对椎弓根相关径线测量结果的临床应用提供依据.方法:分别在27具中国成人干燥颈椎(C3～C7)标本和CT图像上测量椎弓根高度(PH、PH′)、宽度(PW、PW′)、椎弓根轴线的骨性通道全长(TL、TL′)、两种椎弓根长度(PL1...     

颈椎椎弓根螺钉瞄准器的研制与实验

目的探讨在颈椎椎弓根螺钉内固定中使用瞄准器的准确性与可行性.方法8具颈椎标本,经CT平扫测量C3～C7各椎弓根轴线的内偏角度及在关节突上的投射点,X线双斜位片测量椎弓根轴线的头/尾偏角度及在关节突上的投射点.将标本分为两组,用2.8 mm×30 mm的螺钉置入,第1组用手工按定位点及角度直接置入,第2组采用自行研制的可三维调节角度并可术中矫正的颈椎椎弓根螺钉瞄准器置入螺钉.结果第1组C3～C7共40枚螺钉,13枚螺钉位于椎弓根内,9枚穿破椎弓根,但未侵犯临近结构,18枚有脊髓、神经根或椎动脉损伤;第2组C3～C7共40枚螺钉,36枚位于椎弓根内,4枚穿破椎弓根,但未侵犯临近结构.两组比较差异具有显著性(P＜0.01).结论在颈椎椎弓根螺钉的置钉过程中使用瞄准器有利于提高置钉的准确性,可进入临床使用.     

下颈椎前路椎弓根螺钉置入的实验研究

目的 探讨下颈椎前路椎弓根螺钉置入技术的可行性.方法 取18具成人尸体正常颈椎标本,剔除其周围软组织至清楚显露椎体前壁.CT扫描后,用Mimics软件重建三维模型,并测量C3～C7个体化置钉参数,包括进钉点(即椎弓根中轴线在椎体前壁投影点)、置钉方向(螺钉在横断面和矢状面上的倾斜角度)以及螺钉长度.严格按照测量结果,直视下置入椎弓根螺钉.术后作CT扫描,评价置钉效果.结果 进针点:C3、C4位于置钉椎弓根对侧,正中矢状面旁2～3 mm,距上终板6～7 mm;C5～ C7与置钉椎弓根同侧,其中C5位于正中矢状面旁1～2 mm,距上终板7.0～7.5 mm,C6、C7则为4～5 mm和7.5 ～8.5 mm.置钉方向:理想角度在C3、C4为外倾角46°～47°,头倾角-11°～-7°;在C5外倾角约48°,头倾角接近0°;C6、C7为36°～40°和8～13°.螺钉长度:可选择28、30、32 mm,其直径为3.5 mm.本组共置钉144枚.术后CT示,全部螺钉均经椎体前方置入椎弓根内抵达侧块.其中,有16枚胀破椎弓根外侧皮质,3枚穿破外侧皮质(均发生在C3、C4节段).结论 下颈椎前路椎弓根螺钉置入技术是可行的.     

螺旋CT扫描下颈椎对下颈椎椎弓根螺钉的置入作用

目的通过测量颈椎椎弓根尺寸和进钉点进钉角度为置入椎钉提供依据。方法CT测量30例患者颈3-7,CT扫描测量颈椎根以下尺寸,椎根内径、外径、内侧皮质厚度、椎弓根轴长度和椎弓根长轴与中线的夹角。结果颈椎椎弓根平均内径为L3-3.3mm,颈椎椎弓根平均外径为4.0-7.0mm,最小的椎弓根在女性颈3椎体,最小的椎弓根外径为3.2 mm,最大椎弓根宽为C7,男性为11.3 mm,女性为7.4 mm。平均内壁皮质骨厚度为1.5-2.0 mm,平均椎弓根轴长度29.3to-33.7mm和平均椎弓根长轴与中线的夹角39.8度to 49.0度。结论颈椎椎弓根螺钉的置入应行CT测量,螺钉角度接近50度,进钉角度尽可能在侧块的外侧。     

螺旋CT扫描下颈椎为下颈椎椎弓根螺钉的置入提供依据

【目的】通过测量颈椎椎弓根尺寸、进钉点和进钉角度为置入椎弓根螺钉提供依据。【方法】选择2004年12月-2005年10月惠州市中心人民医院骨科收治怀疑颈椎损伤患者60例,男30例,年龄(42.9±18.9)岁,女30例,年龄(42.2±14.9)岁。排除颈椎病理改变。60例患者行颈椎CT扫描,扫描范围C2～T1,扫描电压140kV,200～250mA。【结果】颈椎椎弓根平均内径为1.3～3.3mm,颈椎椎弓根平均外径为4.0～7.0mm,最小的椎弓根宽度在女性颈3椎体,最小的椎弓根外径为3.2mm,最大椎弓根宽为C7,男性为11.1mm,女性为6.6mm。平均内壁皮质骨厚度为1.5～1.9mm,平均椎弓根轴长度29.3～33.7mm,平均椎弓根长轴与中线的夹角40.6°～49.6°,颈椎弓根钉进钉点到中线的垂直距离平均为20.2～23.7mm。【结论】颈椎椎弓根螺钉的置入应行CT测量,螺钉角度接近50°,椎钉角度尽可能侧块的外侧。     

人体颈椎椎弓根钉与侧块钉轴向和切线方向生物力学研究以及与椎体骨密度相关性分析

目的　研究中下颈椎椎弓根钉和侧块钉的固定强度与骨密度的相关性。方法　解离C3 ～C7骨块 12 0个随机分为两组 ,测量每个椎体骨的松质骨密度 ,同一节段椎体随机配对置入椎弓根和侧块螺钉 ,在位移控制下分别测量位移控制下的平均最大拔出阻力和压力控制下的切向弹性与永久位移。结果　椎弓根钉的轴向平均最大拔出阻力明显高于侧块钉 ,切向弹性和固定位移则刚好相反 (均P <0 .0 1) ,在椎体松质骨密度 <12 0mgHA/ml时椎弓根钉和侧块钉的轴向拔出阻力与其呈显著正相关 (P <0 .0 1) ,骨密度 >12 0mg/ml HA时二者无相关性 ,而切线方向的永久位移和弹性位移与骨密度始终呈负相关。结论　椎弓根钉内固定较侧块钉具有更为优越的生物力学强度 ,二者与椎体松质骨密度有显著相关性。     

下颈椎经椎弓根置钉的应用解剖研究

目的 为下颈椎椎弓根螺钉固定提供相关的骨性解剖学基础.方法 对8例成人下颈椎(C3～C7节段)标本进行椎弓根峡部直径、头倾角、内斜角、人点的参考数据测量,并进行统计学处理分析.结果 椎弓根峡部直径,自C3～C7高度呈逐渐增大趋势,C3/C4宽度最小;椎弓根头倾角C4～C7逐渐增加,范围在73～89.之间;内斜角C3～C5逐渐增大,C5～C7逐渐减小,C5最大,C7最小;人点到下关节突水平参考线的距离约9～11 mm,人点到垂直参考线的外侧距离约3～5 mm.结论 依靠解剖结构形态学参考,辅助下颈椎椎弓根钉置入,虽因个体差异具有一定的参考价值,但在实际应用中,仍需结合影像学资料进行事前计划,以提高安全性.     

Mimics及颈椎模型用于下颈椎椎弓根个体化置钉的应用研究

目的利用快速成型技术及Mimics软件设计一种新的下颈椎椎弓根钉个体化置入技术,并探讨其临床应用意义。方法对16例成人下颈椎标本行CT扫描收集数据,导入Mimics软件对标本进行三维重建。利用Mimics相关功能在三维重建图像上寻找下颈椎椎弓根最佳轴线并测量椎弓根相关参数,制定椎弓根螺钉个体化置入方案。然后将三维重建图像以STL格式导入三维打印机,制作出下颈椎的实体模型,根据个体化置钉角度置入导向针。依照制定的个体化指定参数,并配合实体模型的直观指导,在标本上进行置钉。置钉后标本行CT扫描,判断置入准确性。利用上述方法对2例患者进行个体化置钉,术后通过CT扫描验证螺钉位置准确性。结果成功建立了与标本相似度极高的下颈椎三维重建图像和实物模型,通过测量结果设计了每个椎弓根的置钉参数。共在标本上置入148枚椎弓根螺钉,140枚位于椎弓根骨皮质之内,8枚稍穿破椎弓根骨皮质。对患者置入10枚椎弓根螺钉,CT示螺钉位置满意。结论用Mimics软件对下颈椎进行三维重建,制定个体化置钉参数,同时配合实物模型的直观指导,提供了一种下颈椎椎弓根钉个体化置钉的方法,利用该法能提高置钉安全性。     

下颈椎椎弓根前入口及前半四壁皮质厚度的影像学测量及应用分析

目的 对下颈椎椎弓根前入口及椎弓根前半的四壁皮质厚度行CT影像学测量,为前路椎弓根钉准确置入提供参考.方法 对10例正常新鲜尸体的颈椎标本进行CT扫描并重建图像.用AutoCAD 2007软件的“对齐标注”测量下颈椎椎弓根前人口上(SAE)、内(MAE)、下(IAE)和外(LAE)以及椎弓根前半上(SPA)、内(MPA)、下(IPA)和外(LPA)的皮质厚度(精确度0.1 mm),并对测量结果进行比较分析.结果 C3～7左侧和右侧的平均SAE、MAE、IAE、LAE、SPA、MPA、IPA及LPA厚度分别为(1.9±0.6)和(1.9±0.5)mm、(1.9±0.7)和(1.9士0.4) mm、(2.4±0.6)和(2.4±0.5) mm、(0.9±0.5)和(0.9±0.6) mm、(2.3±0.9)和(2.3±0.7)mm、(2.1士0.5)和(2.1±0.6) mm、(2.2±0.8)和(2.2±0.7) mm及(1.0±0.7)和(1.0士0.6)mm.同一颈椎同一测量指标的左、右侧比较差异均无统计意义(P＞0.05).对同一颈椎同侧的不同测量指标行单因素随机区组方差分析,结果示LAE与LPA最薄,均薄于其他6个测量指标,差异有统计学意义(P均＜0.01),而LAE与LPA厚度之间差异无统计学意义(P＞0.05).结论 下颈椎椎弓根LAE及LPA较其他侧壁皮质菲薄,如皮质厚度与抵抗外力强度一致,则LAE和LPA抵抗外力的强度最小.提示颈前路椎弓根螺钉固定寻找前入口时应避免靠近LAE,在螺钉置入过程中应避免靠近LPA.     

Comparison of the clinical accuracy of cervical (C2–C7) pedicle screw insertion assisted by fluoroscopy, computed tomography- based navigation, and intraoperative three-dimensional C-arm navigation

Background The complicated anatomy of the cervical spine and the variation among pedicles reduces the accuracy and increases the risk of neurovascular complications associated with screw implantation in this region. In this study, we compared the accuracy of cervical （C2-C7） pedicle screw fixation assisted by X-ray fluoroscopy, computed tomography （CT）-based navigation, or intraoperative three-dimensional （3D） C-arm navigation.Methods This prospective cohort study was performed in 82 consecutive patients who underwent cervical pedicle screw fixation. The accuracy of screw insertion was assessed by postoperative CT scan with 3D reconstruction. The accuracy of screw insertion was assessed as： excellent （screw completely within pedicle）; acceptable （≤ 1 mm screw outside pedicle cortex）; poor （〉1 mm screw outside pedicle cortex）.Results A total of 145 screws were inserted in 24 patients who underwent C-arm fluoroscopy. Of these, 96 screws （66.2%） were excellent, 37 （25.5%） were acceptable, and 12 （8.3%） were poor. One hundred and fifty-nine screws were inserted in 29 patients in the CT-based navigation group. Among these, 141 （88.7%） were excellent, 14 （8.8%） were acceptable, and 4 （2.5%） were poor. A total of 140 screws were inserted in 29 patients in the intraoperative 3D C-arm navigation group, of which 127 （90.7%） were excellent, and 13 （9.3%） were acceptable. No severe or permanent neurovascular complications associated with screw insertion were observed in any patient.Conclusione CT-based and intraoperative 3D C-arm navigation were similarly accurate, and were both significantly more accurate than C-arm fluoroscopy for guiding cervical pedicle screw fixation. They were able to accurately guide the angle and depth of screw placement using visual 3D images. These two techniques are therefore preferable for high-risk cervical pedicle screw fixation. The ease and convenience of intraoperative 3D C-arm navigation suggests that it may replace virtual-fluoroscopy and CT-based navigation systems in future clinical applications.     

椎弓根螺钉在后路下颈椎重建手术中的应用

目的:探讨应用颈椎椎弓根螺钉后路重建治疗下颈椎疾患的疗效。方法:2001年11月至2003年7月,采用后路椎弓根螺钉内固定治疗下颈椎疾患31例,颈椎椎弓根螺钉进钉点为上位椎体下关节突下端略下方,椎间小关节中央部的略外方(即由侧块的外缘向内约3~5mm),矢状面上内倾30°~45°,钉长为18~26(平均22.3)mm。结果:本组病例置钉193枚,未发生椎动脉和脊髓损伤,术后改善率为84.5%。随访9~28(平均17)月,X线、CT复查示螺钉位置良好,无松动、无断钉,植骨9~12个月左右达到满意的融合。采用日本骨科学会(JOA)评分,由术前平均9.7分提高到术后平均16.3分。结论:颈椎椎弓根螺钉后路重建治疗下颈椎疾患稳定性良好,是可供选择的术式之一。     

In vitro biomechanical evaluation of four fixation techniques for distractive–flexion injury stage 3 of the cervical spine

Abstract

Purpose. Anterior plate fixation has been reported to provide satisfactory results in cervical spine distractive flexion (DF) injuries stages 1 and 2, but will result in a substantial failure rate in more unstable stage 3 and above. The aim of this investigation was to determine the biomechanical properties of different fixation techniques in a DF-3 injury model where all structures responsible for the posterior tension band mechanism are torn.

Methods. The multidirectional three-dimensional stiffness of the subaxial cervical spine was measured in eight cadaveric specimens with a simulated DF-3 injury at C5–C6, stabilized with four different fixation techniques: anterior plate alone, anterior plate combined with posterior wire, transarticular facet screws, and a pedicle screw–rod construct, respectively.

Results. The anterior plate alone did not improve stability compared to the intact spine condition, thus allowing considerable range of motion around all three cardinal axes (p > 0.05). The anterior plate combined with posterior wire technique improved flexion–extension stiffness (p = 0.023), but not in axial rotation and lateral bending. When the anterior plate was combined with transarticular facet screws or with a pedicle screws–rod instrumentation, the stability improved in flexion–extension, lateral bending, and in axial rotation (p < 0.05).

Conclusions. These findings imply that the use of anterior fixation alone is insufficient for fixation of the highly unstable DF-3 injury. In these situations, the use of anterior fixation combined with a competent posterior tension band reconstruction (e.g. transarticular screws or a posterior pedicle screws–rod device) improves segmental stability.     

成人中上胸椎椎弓根钉进钉点与后柱骨性标志的定位关系和变化规律的影像学测量

目的 通过三维重建CT图像测量参数探讨成人中上胸椎椎弓根钉进钉点(PSEP)与后柱骨性标志的定位关系和变化规律.方法 选取排除了畸形的30例成人中上胸椎CT图像进行三维重建,观察横突椎板凹、横突上嵴和椎板外缘等后柱骨性标志的解剖特征.在重建后的T1～T10特定CT图像上测定以下参数:(1)基础参数,即PSEP至中线的距离(PMD)、横突椎板凹至中线距离(CMD)和半椎板宽度(HLW);(2)目标参数,即点凹距离(PCD)、进钉点定位比(EPLR)和点嵴距离(PRD).比较所有参数两侧测量值的差异和基础参数间测量值的差异,总结从T1到T1o目标参数测量值的变化规律.结果 中上胸椎横突椎板凹、横突上嵴和椎板外缘具有解剖标志明显、恒定且少有增生的特征.T1～T10左右两侧PMD分别为(14.14±2.63) mm和(14.59土2.58) mm,CMD分别为(10.45±2.12) mm和(10.51±2.02) mm,HLW分别为(16.30±1.48) mm和(16.39±1.61) mm,PCD分别为(4.56土1.03) mm和(4.47±0.94) mm,EPLR分别为0.35±0.26和0.33±0.30,PRD分别为(-1.62±1.90)mm和(-1.63±1.44) mm.所有参数两侧测量值差异均无统计学意义(P＞0.05).除T2中PMD和HLW相比差异无统计学意义(P＞0.05),其余节段基础参数间测量值差异均有统计学意义(P＜0.01).从T1到T10,PCD呈现先减小再增大的趋势,T1、T2、T9、T10处PCD均高于T3～T8处(P＜o.05);EPLR呈现先增大再减小的趋势,T1～T3处EPLR与其下方任一节段相比差异均有统计学意义(P＜0.01),T4～T6、T1o处均低于T7～T9处(P＜0.01);PRD呈现先增大再减小的趋势,T1～T3处PRD与其下方任一节段相比差异均有统计学意义(P＜0.01),T4～T6处均低于T7～T10处(P＜0.01).结论 中上胸椎PSEP与横突椎板凹、横突上嵴和椎板外缘等后柱骨性标志存在相对恒定的定位关系和变化规律,可作为一种新的临床上选择进钉点的方法.     

伤椎置钉与不置钉短节段内固定治疗胸腰椎爆裂骨折的疗效对比

目的:探讨伤椎置钉与不置钉短节段内固定治疗胸腰椎爆裂骨折的疗效.方法:本研究选取了108例胸腰椎爆裂性骨折患者,按照入院时间顺序不同分为两组,不置钉组(52例)行短节段椎弓根螺钉内固定治疗,置钉组(56例)行伤椎置钉联合短节段内固定治疗.观察并记录患者围手术期指标,伤椎前缘高度比,伤椎后缘高度比,Cobb's角,生活质量及随访12个月期间并发症发生情况,以评价伤椎置钉联合短节段内固定治疗胸腰椎爆裂性骨折疗效.结果:置钉组与不置钉组在术中失血量,手术时间和住院时间上相比,差异没有统计学意义;与术前相比,术后两组伤椎前缘高度比,伤椎后缘高度比均明显提高,Cobb's角明显下降,且置钉组与不置钉组在伤椎高度比和Cobb's角上相比,差异具有明显的统计学意义;术后6个月,两组SF-36各项得分均明显升高,置钉组在仅躯体疼痛这一项,评分明显高于不置钉组.随访12个月期间,两组并发症发生率比较,差异没有统计学意义.结论:综上所述,伤椎置钉联合短节段内固定治疗胸腰椎爆裂性骨折,固定方式更符合生物力学稳定性,能恢复并维持伤椎高度,改善患者生活质量,减少术后后凸畸形,值得临床推广使用.     

Dynamic Radiographic Analysis of Sympathetic Cervical Spondylosis Instability

Objective To investigate the correlation between subaxial cervical spine instability and cervical spondylotic sympathetic symptoms as well as the difference of cervical spondylotic subaxial instability between male and female patients. Methods We analyzed retrospectively 318 surgical cases of cervical spondylosis treated at Department of Orthopedic Surgery of Peking Union Medical College Hospital between July 2003 and December 2007. All cases were divided into group A without sympathetic symptoms （n=284） and group B with sympathetic symptoms （n=34）. Angular and horizontal translation values between two adjacent vertebral bodies from C2 to C7 were measured separately on hyperflexion and hyperextension lateral cervical spine radiographs. Fisher＇s exact test was used to evaluate the correlation between subaxial cervical instability and sympathetic symptoms. Intragroup correlation between patient gender and subaxial cervical instability was also evaluated. Results Subaxial instability incidences in groups A and B were 21.8% （62/284） and 55.9% （19/34）, respectively. Statistical analysis indicated a definite correlation between subaxial cervical instability and sympathetic symptoms （P=0.000）. Among patients without sympathetic symptoms, subaxial instability incidences were 21.4% （37/173） in males and 22.5% （25/111） in females, respectively （P=0.883）. While among patients with sympathetic symptoms, sub axial instability incidences were 27.3% （3/11） in males and 69.6% （16/23） in females, respectively, indicating significant difference （P=0.030）. Subaxial instability was most commonly seen at C4-C5 intervertebral space in sympathetic cervical spondylosis patients. Conclusions High correlation exists between subaxial cervical spine instability and cervical spondylotic sympathetic symptoms, especially in female patients. Hyperextension and hyperflexion radiographs of cervical spine are important to assess sympathetic cervical spondylotic subaxial instability.