颈椎椎弓根螺钉徒手植入技术临床研究

目的：评价颈椎椎弓根螺钉徒手植入技术(无须术中影像技术引导)的安全性和可靠性。方法：作者应用Axis内固定系统(美国枢法模公司)对36例颈椎疾病患者进行颈后路经椎弓根内固定术,共植入螺钉144枚。椎弓根螺钉植入要点为：①术前仔细观察颈椎的侧位和双斜位x线片,并予以CT扫描以评估螺钉进针点、进针方向以及螺钉的长度及直径：②术中清晰地显露颈椎侧块和突间关节,用直径3．0mm高速球形磨钻去除侧块外卜象限处骨皮质,然后用2.0mm的自制手锥沿椎弓根事先确定的方向轻轻钻入,若遇阻力则需略改变方向,使其自然置入,深约2．0cm～2．5cm。确定无误后,则安置Axis钛板和置入长度合适的椎弓根螺钉;③安装完毕后,即用C掣臂作双斜位透视,无误后关闭切口。结果：从C3到C7,共植入根弓根螺钉144枚,其中10枚(6．8％)钉初次置入后感觉松动,经校正后二次置入成功,11枚(3．5％)钉道钻孔后出血较多,但及时处理后出血停止并无不良结果。术后X线斜位片及CT片显示,16枚(11．1％)螺钉穿破椎弓根,其中10枚(6．9％)螺钉穿破椎弓根外侧皮质,4枚(2,8％)钉穿破椎弓根上侧皮质,2枚(1．3％)钉穿破椎弓根卜侧皮质。随访未发现与螺钉置入穿破椎弓根皮质仃关的神经血管损伤问题。结论：本研究提示,在事先充分的埘每个患者颈椎椎弓根X线及CT解剖结构了解的情况下,徒手置入椎弓根螺钉行颈椎后路内同定是安全查行。     

颈椎椎弓根螺钉内固定术中并发症及其对策

目的：探讨颈椎椎弓根螺钉固定技术常见并发症及其处理方法。方法：应用Axis内固定系统（美国枢法模公司）对69例颈椎病患者进行经后路椎弓根内固定术，术中清晰显露颈椎侧块和突间关节，用直径3．2mm高速球形磨钻去除侧块外上象限处骨皮质，然后用直径2．0mm的手锥沿椎弓根事先确定的方向轻轻钻入，使其自然置入，深约2．0～2．5cm。确定无误后，则安置Axis钛板和置入长度合适的椎弓根螺钉，完毕后用C形臂X线机作双斜位透视。结果：从C3到C7，术中植入椎弓根螺钉314枚，其中21枚钉初次置入后感觉松动，经校正后二次置入成功，17枚钉道钻孔后出血较多，但及时处理后出血停止并无不良结果，其余螺钉置钉一次成功，未出现并发症。术后检查有28枚螺钉穿出椎弓根，6枚螺钉穿破椎弓根上侧皮质，3枚螺钉穿破椎弓根下侧皮质，12枚螺钉穿破椎弓根外侧皮质，7枚螺钉穿破椎弓根内侧皮质。随访未发现与螺钉置入穿破椎弓根皮质相关的神经血管损伤问题。结论：手术前充分了解每个患者颈椎椎弓根影像学解剖结构，术中仔细按原则操作，正确处理则会明显减少术中及术后并发症的发生。     

改良3D打印导板辅助颈椎椎弓根螺钉置钉的准确性研究

【摘要】 目的：探讨改良3D打印导板辅助颈椎椎弓根螺钉置钉的准确性。方法：回顾性分析2016年1月~2023年1月在我院行颈椎后路椎弓根螺钉内固定手术的60例患者的临床资料,其中男30例,女30例,年龄58.7±13.8岁（17~84岁）;根据颈椎后路手术是否使用导板辅助置钉分为导板组及徒手置钉组。导板组（30例）采用改良3D打印导板辅助颈椎椎弓根置钉,徒手置钉组（30例）采用角度尺辅助颈椎弓根置钉,两组患者年龄、性别、术前诊断无统计学差异（P＞0.05）。所有患者术后1周行颈椎CT扫描,按照Kaneyama标准判断椎弓根置钉准确性：0级,螺钉完全处于椎弓根中,没有穿破骨皮质;1级,螺钉穿破皮质<螺钉直径的50％;2级,螺钉穿破皮质≥螺钉直径的50％但没完全穿出;3级,完全穿出骨皮质。记录椎弓根置钉准确率（0级+1级螺钉占比）及因螺钉误置导致的血管神经损伤、切口感染、脑脊液漏、螺钉松动断裂等并发症。结果：导板组共置入椎弓根螺钉152枚,其中0级74枚,1级68枚,2级10枚,3级0枚,置钉准确率93.4%;徒手置钉组共置入椎弓根螺钉136枚,其中0级53枚,1级61枚,2级18枚,3级4枚,置钉准确率83.8%,导板组置钉准确率高于徒手置钉组（P＜0.05）。所有患者均未出现因椎弓根螺钉误置导致的血管神经损伤、切口感染及脑脊液漏等相关并发症。所有患者随访5～29个月（14.2±7.7个月）,无内固定松动、断裂等并发症。结论：改良3D打印导板辅助颈椎椎弓根置钉可提高置钉精准度。     

下颈椎前路椎弓根螺钉固定系统的设计与运用

目的：研究下颈椎前路椎弓根螺钉钢板系统运用的可行性,为临床使用提供依据。方法：对16具颈椎标本随机分割获得C3．4,C4加C5．6,C6,7各8个运动单元（functionalspinalunit,FSu）,共32个FSU。运用下颈椎前路椎弓根螺钉钢板系统模拟植入重建FSU稳定性。测量钢板螺钉与椎体之间的适应性,运用X线摄片及CT扫描及重建评估下颈椎前路椎弓根螺钉植入的准确性,对于穿破椎弓根的标本,解剖明确其累及周围组织的情况。结果：32个FSU共计植入下颈椎前路椎弓根螺钉64枚,所有螺钉均顺利植入,无术中植入困难者。螺钉植入后与钢板螺钉孔之间的匹配程度好,未见难以锁紧的情况。钢板与椎体之间适应性良好。X线片提示所有64枚下颈椎前路椎弓根螺钉植入位置满意,螺钉长短合适。CT横断位像提示共有6枚螺钉在下颈椎椎弓根穿出,2枚内侧皮质1度穿破,4枚1度外侧缘皮质穿破累及横突孔内侧缘,未见螺钉≥2度穿破椎弓根。2枚下颈椎前路椎弓根内侧皮质1度穿破的患者,解剖发现仅有椎管内椎弓根内侧的静脉丛累及,未见硬膜囊受压,未见神经根受累。4枚1度外侧缘穿破的患者有1枚横突孔内椎静脉的累及,未见椎动脉穿破累及的情况,但其中1枚螺钉紧换椎动脉而行。结论：下颈椎前路椎弓根螺钉钢板系统适应下颈椎前路椎弓根螺钉固定重建,有临床运用价值。     

X线分步监测胸腰椎椎弓根螺钉植入的实验研究

[目的]探讨X线分步监测胸腰椎椎弓根螺钉准确置入的可行性。[方法]选8具T9～L5脊柱标本，随机分A、B两组，每组4具。A组按X线分步监测方法置入椎弓根螺钉。CT扫描测量椎弓根一半长、全长及螺钉通道长度和椎弓根e角及f角。当导针进至深度为椎弓根一半时，标准正位片导针远端到达椎弓根投影中线为符合标准；当导针进至深度为椎弓根全长时，腰椎到达椎弓根投影3／4处为符合标准，而胸椎到达椎弓根投影的1／2与3／4的中线处为符合标准；导针进入椎体，调整X线机臂，侧位片观察导针深度及f角。按照导针轨道植入椎弓根螺钉。B组为对照组，按传统X线监测方法置入椎弓根螺钉。通过观察两组螺钉的位置，评估A组方法的准确性。[结果]A组植入螺钉72枚：68枚位于椎弓根内，左右螺钉基本对称；4枚穿破椎弓根，穿破率为5．56％。B组亦为72枚：53枚位于椎弓根内；19枚穿破椎弓根，穿破率为26．38％。A组优于B组（P〈0．001）。[结论]X线分步监测胸腰椎椎弓根螺钉的置入，可克服传统X线平片的局限性及减少置钉过程中的人为因素干扰，在一定程度上可使两侧椎弓根螺钉对称植入，提高了螺钉置入的准确性。     

多层螺旋CT三维重建技术在胸腰椎骨折经椎弓根螺钉内固定术中的应用价值

目的:探讨多层螺旋CT(MSCT)三维重建技术在胸腰椎骨折患者经椎弓根螺钉内固定术中的应用价值。方法:2007年1月~2008年12月,78例胸腰椎骨折患者在我院行椎弓根螺钉内固定术,其中38例使用传统置钉法(Weinstein法或AO法)进行椎弓根螺钉置入(A组),40例采用MSCT三维重建设计钉道的置钉方法进行螺钉置入(B组),术后两组均复查胸腰椎正、侧位X线片和CT了解置入螺钉位置情况,应用Lonstein等的方法评判置钉准确率。结果:78例患者共置入椎弓根螺钉436枚,A组38例共置入212枚,12例32枚螺钉穿破椎弓根皮质,其中穿破椎弓根内外皮质21枚,穿破椎弓根上下皮质11枚,置钉准确率84.91%;B组40例共置入224枚,5例6枚螺钉穿破椎弓根皮质,其中穿破椎弓根内外皮质4枚,穿破椎弓根上下皮质2枚,置钉准确率97.33%。两组置钉准确率有统计学差异(P<0.05)。结论:胸腰椎骨折患者行椎弓根螺钉内固定时应用MSCT三维重建设计钉道的置钉方法较传统置钉方法成功率高。     

3D打印导航模板引导双侧下颈椎前路椎弓根螺钉置钉的可行性

目的 :通过3D打印技术及骨科数字化技术制作下颈椎前路椎弓根螺钉置钉导航模板,观察模板辅助下置钉的准确性。方法:选取正常成人颈椎湿性标本10具(男、女各5具),将椎前软组织剔除,采用64排薄层CT扫描后获取其DICOM格式数据,导入Mimics软件后三维建模并为颈前路椎弓根螺钉选取理想钉道,设计建立螺钉导航模板后导出其STL数据,通过3D打印机快速打印成型。在导航导板引导下进行下颈椎前路椎弓根螺钉置钉,通过X线及CT评价螺钉的准确性。结果:10具尸体分别于C3~T1每节段置入2枚螺钉,共计120枚,根据螺钉的位置将其分为4级:0级,螺钉完全在椎弓根内,共115枚;1级,螺钉穿破椎弓根皮质,穿出部分小于螺钉直径的25%,1枚;2级,螺钉穿破椎弓根皮质,穿出部分为螺钉直径的25%~50%,3枚;3级,螺钉穿出椎弓根部分大于螺钉直径的50%,1枚。5枚穿破椎弓根皮质者2枚穿破椎弓根内侧皮质,3枚穿破外侧皮质,总体准确性为95.8%。结论:在湿性尸体颈椎标本上应用3D打印及骨科数字化技术制作的导航模板辅助行下颈椎前路椎弓根螺钉置钉的准确性高,为临床应用提供了依据。     

钉道设计在颈椎椎弓根固定中的应用

[目的]探讨钉道设计在颈椎椎弓根固定中的应用.[方法]2006～2009年16例患者在本院接受下颈椎椎弓根螺钉内固定术,术前采用颈椎螺旋CT三维重建,测量该组患者颈椎椎弓根的长度、宽度、高度、向内侧倾斜、向头侧倾斜、向尾侧倾斜角度的数据,以此为指导行术中置入椎弓根螺钉.术后半月内采用与术前程序一致的螺旋CT三维重建及钉道扫描,观察椎弓根螺钉与椎弓根各壁的关系.[结果]颈椎弓根变异较大.本组共置钉66枚,57枚螺钉完全位于椎弓根内,9枚螺钉穿破椎弓根外侧皮质壁,其中5枚穿破距离为1 mm,4枚螺钉穿破距离为2～3 mm,无椎动脉和脊髓损伤发生,置钉准确率为93%.[结论]钉道设计对术中个体化置入颈椎弓根螺钉有重要意义.     

徒手胸椎椎弓根螺钉置入技术治疗青少年特发性脊柱侧凸的安全性评价

目的 评价徒手胸椎椎弓根螺钉置入技术治疗青少年特发性脊柱侧凸的安全性。方法从2002年7月～2004年6月对38例青少年特发性脊柱侧凸患者，徒手应用胸椎椎弓根螺钉进行后路矫形内固定，所有患者术中进行神经电生理监测及X线透视确认，术后进行X线成像、CAT扫描评估螺钉位置，并对其中35例进行随访，从而评价本技术的安全性。结果共置入胸椎椎弓根螺钉326个，每一水平置入的螺钉数如下：T1,n=2；T2，n=10;T3，n=19；T4，n=27；L，n=28；T6，n=24；T7，n=23；TB，n=25；T9，n=29；T10,n=34；T11,n=48；T12，n=57。通过胸椎CT扫描评价326枚置入畸形胸椎的螺钉位置。共有19枚螺钉（5．8％）有中等程度的皮质穿破，即螺钉的中线在椎弓根壁皮质之外，其中6枚螺钉（1．8％）穿破椎弓根内侧壁。对35例患者进行术后跟踪随访，平均随访时间2年，未发现任何与置入的胸椎椎弓根螺钉（全部326枚螺钉）相关的神经、血管或内脏并发症。结论遵循严格步骤，逐步置入胸椎椎弓根螺钉的徒手技术在治疗青少年特发性脊柱侧凸中具有可靠的安全性。     

椎弓根螺钉在颈胸段骨折脱位中的临床运用

目的：评价椎弓根螺钉技术在颈胸段骨折脱位（C6-T2）中的运用价值。方法：2001年5月至2008年1月运用椎弓根螺钉植入技术治疗颈胸段骨折脱位患者26例,男17,女9例;年龄20-75岁,平均48．5岁。采用单纯后路椎弓根螺钉技术17例,后路椎弓根螺钉技术结合前路减压钢板内固定9例。术后3d运用CT平扫及重建片观察评价植入颈胸段椎弓根螺钉的准确性、螺钉植入相关并发症;随访观察患者颈胸段术后植骨融合情况;统计患者术前与术后6个月JOA评分及ASIA分级改善情况,综合评价患者脊髓及神经功能改善情况。结果：所有患者获得随访,随访时间3～74个月,平均36．5个月。4例完全性瘫痪患者术后6个月内死亡。共计植入椎弓根螺钉104枚,其中颈椎椎弓根74螺钉枚（其中：C516枚,C616枚,C742枚）,胸椎椎弓根螺钉30枚（其中：T1 22枚,T28枚）,所有椎弓根螺钉在术中均成功植入,无脊髓、神经根及椎动脉损伤。术后CT提示颈椎椎弓根螺钉11枚（14．9％）穿破椎弓根,其中7枚（9．5％）穿破外侧皮质,1枚（1．4％）穿破椎弓根上侧皮质,3枚（4．1％）穿破椎弓根下侧皮质。胸椎椎弓根螺钉中,3枚（10％）穿破胸椎椎弓根,其中2枚（6．7％）穿出椎弓根外侧缘,1枚（3．3％）穿破内侧缘（〈2mm）,但无临床症状。术后随访1枚C,椎弓根螺钉断裂,但患者无明显临床症状,其余无螺钉松动及断钉情况出现。所有患者固定良好,并均达到骨性融合。术后6个月患者平均JOA评分由术前（7．5±2．0）分恢复到（14．5±2．3）分,差异有统计学意义（t=6．34,P〈0．05）。ASIA分级情况,除3例完全性瘫痪患者脊髓功能术后无明显改善外,余患者术后脊髓神经功能均有不同程度恢复。结论：椎弓根螺钉在颈胸段骨折脱位治疗中安全、可靠。术者应熟练掌握颈胸段后?     

A free‐hand technique for pedicle screw placement in the lower cervical spine

Objective: To describe a free‐hand method for pedicle screw placement in the lower cervical spine with no intraoperative imaging monitors, and to evaluate the safety of this technique. Methods: A study of the free‐hand technique of cervical pedicle screw placement was conducted by postoperative radiological review and follow‐up. Thirty‐six patients who had had cervical reconstruction with posterior plate utilizing pedicle screw fixation, and been followed for a minimum of 2 years, were studied. The position of the pedicle screw was evaluated by postoperative oblique radiographs and axial computed tomograms. Clinical outcomes were measured by Odem's criteria. Results: A total of 144 screws of diameter 3.5 or 4.0 mm were inserted into the cervical pedicles in 36 patients. Postoperative images showed that 16 (11.1%) of the screws had penetrated the pedicle walls. Among them, 10 (6.9%) screws had penetrated the lateral, 4 (2.8%) the superior and 2 (1.3%) the inferior walls. However, there were no neurological or vascular complications related to the malpositioned screws during a minimum of 2 years follow‐up. In addition, Odem's scores were applied postoperatively in all patients except one with complete neurological deficit. Conclusion: Based on 144 screw placements, cervical pedicle screw insertion utilizing a free‐hand technique without intraoperative imaging guidance seems to be safe and reliable. However, solid knowledge of the anatomy of the cervical pedicle and adjacent neurovascular bundles, and careful preoperative review of cervical images, are imperative for successful screw placement in the cervical spine.     

胸椎椎弓根螺钉置入位置的CT评价

目的:探讨胸椎椎弓根螺钉置入的准确性和安全性。方法:对37例胸椎椎弓根螺钉内固定患者术后行CT断层扫描,观察螺钉在椎弓根内的位置,记录螺钉穿透骨壁的位置、数目和距离。结果:37例患者共置入405枚胸椎椎弓根螺钉,124枚螺钉(30.61%)穿透骨壁,其中76枚(18.77%)穿透椎弓根外侧壁,32枚(7.90%)穿透椎弓根内侧壁,16枚(3.95%)穿透椎体前壁。66枚(16.30%)穿透距离<2mm,37枚(9.14%)穿透距离在2mm~4mm之间,21枚(5.9%)穿透距离>4mm。结论:胸椎椎弓根螺钉骨壁穿透率较高,应严格按照胸椎椎弓根螺钉置入方法,仔细操作,避免出现因螺钉置入不当造成神经、血管或内脏损伤等并发症。     

导向器结合钉道内壁探查法在下颈椎椎弓根螺钉置入中应用研究

目的:探讨导向器结合钉道内壁探查法置入下颈椎弓根螺钉的技巧并评价其准确性及安全性。方法:2014年1月至2016年10月采用自行设计带角度仪导向器结合钉道内壁探查法对11例患者置入下颈椎椎弓根螺钉,其中男7例,女4例;年龄32~63岁,平均48.1岁;脊髓型颈椎病4例,颈椎骨折脱位4例,无骨折脱位颈脊髓损伤1例,寰枢椎骨折脱位2例。术前CT测量出目标椎弓根直径、理想进钉点及矢状面夹角和横断面内倾角。术中使用自行设计带角度仪导向器严格控制进钉角度,结合探查钉道内壁作为安全置钉标志。术后观察患者有无脊髓及椎动脉损伤表现,复查CT评价椎弓根螺钉位置,并将螺钉准确性进行分级,计算螺钉优良率。结果:11例患者共置入71枚下颈椎弓根螺钉,均未出现手术所导致的脊髓及神经根损伤症状,亦无椎动脉损伤症状。术后CT评估螺钉位置并进行分级:0级52枚,1级13枚,2级4枚,3级2枚。螺钉位置良好率91%。6枚误置螺钉,内壁穿破4枚,2枚穿破外壁。结论:钉道内壁探查法置入下颈椎弓根螺钉安全可靠,但有一定的学习曲线。术中探查出钉道内壁及使用角度仪导向器控制进钉角度是置钉关键。     

Evaluation of a transpedicular drill guide for pedicle screw placement in the thoracic spine

Insertion of pedicle screws in the thoracic spine is technically difficult and may lead to major complications. Although many computer-assisted systems have been developed to optimize pedicle screw insertion, these systems are expensive, not user-friendly and involve significant radiation from pre-operative computed tomographic (CT) scan imaging. This study describes and evaluates a transpedicular drill guide (TDG) designed to assist in the proper placement of pedicle screws in the thoracic spine. Pilot holes were made manually using the TDG in the thoracic spine (T1-T11) of three human cadavers before inserting 4.5-mm-diameter screws. CT scans followed by visual inspection of the spines were performed to evaluate the position of the screws. Five of 66 screws (7.6%) violated the pedicle wall: two (3.0%) medially and three (4.5%) laterally. The medial and lateral perforations were within 1 mm and 2 mm of the pedicle wall, respectively. The medial perforations were not at risk of causing neurological complications. No screw penetrated the superior or inferior pedicle wall. The TDG is easy to use and can decrease the incidence of misplaced thoracic pedicle screws. The TDG could be used as a complement to fluoroscopy in certain applications, especially for training surgeons.     

Accuracy of single-time, multilevel registration in image-guided spinal surgery.

BACKGROUND CONTEXT: Computerized frameless stereotactic image-guidance has been used in recent years to improve the accuracy and safety of pedicle screw placement during spine surgery. Because the possibility of intervertebral motion exists, and because the patient is usually in a different position when preoperative imaging is performed compared with the operative position, it has been suggested that the imaging model of the complete lumbar spine and the surgically exposed lumbar spine may be significantly discordant. Consequently, current protocols suggest registering each spinal level (single-level registration) separately before pedicle screw placement at that level, a time-consuming process. PURPOSE: To assess the accuracy of single-time multilevel registration for multilevel pedicle screw placement during image-guided, computer-assisted spine surgery, in the setting of degenerative disorders of the lumbar spine. STUDY DESIGN/SETTING: This is a prospective clinical and radiological study of 45 patients with degenerative disorders of the lumbar spine who underwent instrumented fusion with the use of single-time multilevel registration computer-assisted, image-guided tomography. The accuracy of the pedicle screws placement was confirmed on the basis of a protocol that included intraoperative spontaneous electromyographic (EMG) recordings, direct pedicle visualization, and computer tomography (CT) scans when clinically indicated during the follow-up period. PATIENT SAMPLE: Forty-five consecutive patients who fulfilled the criteria of computer-assisted, image-guided tomography pedicle screw placement for degenerative lumbar spine disease without overt instability. OUTCOME MEASURES: The principal outcome measure was the accuracy of pedicle screw placement with single-time multilevel registration for multilevel pedicle screw placement during image-guided, computer-assisted spine surgery; postoperative CT performed for clinical indications during the follow-up course was used for the assessment of pedicle screw placement. METHODS: Patients were assessed clinically before and after the operation. Data from 45 consecutive cases of image-guided, computer-assisted lumbar spinal fusion were statistically analyzed to determine the relationship between the number of levels registered during single-time registry and the mean registration error (MRE). Intraoperative spontaneous EMG, direct visualization, and postoperative CT scans were used to assess the accuracy of pedicle screw insertion. RESULTS: None of the patients involved in this study experienced clinical sequelae of improper pedicle screw placement. MREs after surface mapping and after point merge were small (less than 1.00 mm and less than 3.00 mm, respectively). During the intraoperative assessment of the pedicle screws placement, no significant spontaneous EMG activity was recorded and the pedicular walls were found intact in direct visualization. The postoperative CT scans showed in 10 patients accurate placement in 55 of the 57 pedicle screws with expansion of the medial wall in two screws. CONCLUSIONS: Single-time, multilevel registration may decrease operative time relative to repeated, single-level registrations, without compromising the increased accuracy of pedicle screw placement afforded by this technique in the setting of degenerative disorders of the lumbar spine. Despite the advantages in computer-guided image surgery, cautious application in the individual patient is recommended until more comprehensive data can be gathered in specific degenerative pathology with overt instability; thus the knowledge of the anatomy remains crucial.     

管道疏通法行颈椎弓根螺钉置入的研究

目的：通过解剖学测量及临床应用探讨“管道疏通法”（dredging pipe method,DPM)对提高颈椎弓根螺钉置入的成功率、安全性及可操作性方面的应用价值。方法：（1）颈椎骨测量：成人C3－C7干燥骨42套，共210块椎骨，在实体及CT片上，测量椎骨的相关参数；92）临床应用：颈椎失稳症患者32例，术前X线、CT测量，参照标本及患者影像测量数据和管道疏通器自动寻迹的原理，个体化设计各椎节的置钉方案。在直视下显露椎弓根管口及其管腔，确定置钉方向和位置，扩孔攻丝置钉。术后观察对比相应指标，评价置钉的位置、方向。结果：91）与DPM相关的国人颈椎实体测量数据与CT测量数据比较无显著性差异（P＞0．05）；6．67％（28／42）椎弓根的宽度小于4mm;(2)32例患者共置入颈椎弓根钉146枚，术后CT复查96枚钉，其中5枚螺钉穿破椎弓根骨皮质，成功率94．8％。未出现神经血管损伤病例。结论：（1）术前影像学测量结果可人为个体化设计手术方案的重要依据，采用DPM置钉技术实施经颈椎弓根钉内固定手术，具有直视下操作、置钉准备率高、可操作性强等特点；（2）解剖学测量表明，极少部分人（6．67％）的C3－C7的椎弓根宽度不适宜做椎弓根钉内固定。     

Spinal reconstruction using a cervical pedicle screw system

Although the cervical pedicle screw system is considered the most effective instrumentation for posterior cervical spine surgery, reports on clinical application are limited because of the unresolved and inherent risk of neurovascular complications. The purpose of this study is to retrospectively evaluate the accuracy of placement and clinical effectiveness of the cervical pedicle screw. The cases of 26 patients were investigated. The average followup was 20 months. All but one patient had simultaneous decompression and fusion of various extent. In these cases, screw placement, alignment of the fused segment, fusion rate, neurologic improvement, and complications were assessed. Using an image intensifier, 134 screws were inserted. Five screws (3.7%) completely perforated and 10 (7.4%) partially perforated. The complete perforations occurred in the first 10 patients. Except for two patients with metastasis, bony union was obtained in all patients without loss of correction. Neurologic impairment also was improved in all patients, and no complications associated with the cervical pedicle screw were seen. Clinical results of the cervical pedicle screw system were excellent with few complications. However, there is the possibility of screw perforation, which could cause neurovascular complications. Increased accuracy of screw insertion is needed to make this instrumentation safer.     

Complications of pedicle screw fixation in reconstructive surgery of the cervical spine

STUDY DESIGN: Retrospective evaluation of complications in 180 consecutive patients with cervical disorders who had been treated by using pedicle screw fixation systems. OBJECTIVES: To determine the risks associated with pedicle screw fixation in the cervical spine and to emphasize the importance of preoperative planning and surgical techniques in reducing the risks of this procedure. SUMMARY OF BACKGROUND DATA: Generally, pedicle screw fixation in the cervical spine has been considered too risky for the neurovascular structures. There have been several reports describing the complications of lateral mass screw-plate fixation. However, no studies have examined in detail the complications associated with cervical pedicle screw fixation. METHODS: One hundred eighty patients who underwent cervical reconstructive surgery using cervical pedicle screw fixation were reviewed to clarify the complications associated with the pedicle screw fixation procedure. Cervical disorders were spinal injuries in 70 patients and nontraumatic lesions in 110 patients. Seven hundred twelve screws were inserted into the cervical pedicles, and the locations of 669 screws were radiologically evaluated. RESULTS: Injury of the vertebral artery occurred in one patient. The bleeding was stopped by bone wax, and no neurologic complication developed after surgery. On computed tomographic (CT) scan, 45 screws (6.7%) were found to penetrate the pedicle, and 2 of 45 screws caused radiculopathy. Besides these three neurovascular complications directly attributed to screw insertion, radiculopathy caused by iatrogenic foraminal stenosis from excessive reduction of the translational deformity was observed in one patient. CONCLUSIONS: The incidence of the clinically significant complications caused by pedicle screw insertion was low. Complications associated with cervical pedicle screw fixation can be minimized by sufficient preoperative imaging studies of the pedicles and strict control of screw insertion. Pedicle screw fixation is a useful procedure for reconstruction of the cervical spine in various kinds of disorders and can be performed safely.     

Accuracy of fluoroscopically assisted laser targeting of the cadaveric thoracic and lumbar spine to place transpedicular screws

A simple and inexpensive method was developed to obtain a coaxial view of the pedicles to assist with screw insertion. The authors evaluated the accuracy of this device to place transpedicular vertebral screws in a human adult cadaver model. A dual radiation targeting system, a laser targeting system for fluoroscopically guided procedures, was developed to provide an accurate surface entry point and angle of approach to radiographic landmarks. After fluoroscopic cross-hair target localization of the coaxial view of the pedicle, X-ray radiation is turned off and the laser beam allows the surgeon to guide the screw through the pedicle. Nine cadaver spines were removed and mounted. Three surgeons, inexperienced in the technique of pedicle screw placement, fitted instruments to 184 pedicles between L5 and T5. A total of 83 lumbar and 101 thoracic pedicles underwent screw placement. After specimen dissection, the degree and location of any screw perforation were measured by direct inspection. Three screws perforated a pedicle, for an error rate of 1.6%. Two lumbar screws (2.4% error) and one thoracic screw (1% error) perforated the pedicle. No screw was more than 1 mm outside the pedicle. Five other screws, four in the thoracic spine and one in the lumbar spine (error rate of 2.7%) were directed too far laterally and perforated the lateral vertebral body. This low rate of pedicle wall cortical perforation by inexperienced surgeons compares favorably with much higher pedicle perforation rates by experienced surgeons when no imaging was used. In conclusion, this in vitro model using a dual radiation targeting system assisted with the accurate placement of transpedicular vertebral screws with minimal radiation exposure.     

The risks of pedicle wall breech with larger screws after undertapping.

BACKGROUND CONTEXT: A linear relation exists between the insertional torque when placing a screw and the ultimate screw pullout strength; therefore, undertapping of the pedicle followed by insertion of a larger screw may enhance the pullout strength of the screw. PURPOSE: To report the risk of pedicle wall breech with placement of 6.2-mm pedicle screws after undertapping with a 5.2-mm tap and to evaluate the effectiveness of direct visualization to identify these breeches. STUDY DESIGN/SETTINGS: Prospective evaluation of risks of pedicle wall breech with undertapping for a larger screw and the utility of directly visualizing pedicle walls during access and placement of pedicle screws for evidence of breech. PATIENT SAMPLE: Sixty-five consecutive patients. OUTCOME MEASURES: Intraoperative direct visualization of pedicle wall breech. Postoperative radicular leg symptoms. METHODS: We prospectively analyzed placement of pedicle screws in sixty-five consecutive patients during lumbar-instrumented fusions after laminectomies performed by a single spine surgeon. Forty-four patients were primary fusions, and 21 were revisions. Twenty-seven were male, and 38 were female, with a mean age of 54.7 years (range, 15-85 years). Four hundred twenty-eight total pedicle screws were placed for an average of 6.6 screws per patient (range, 2-12 screws). RESULTS: The incidence of pedicle wall breech during access was 0.7% (3/428) and 1.6% (7/428) after screw placement. 71% (5/7) of the screw breeches were noted with direct inspection of the pedicles intraoperatively, and 29% (2/7) were identified on postoperative X-ray films as lateral breakthroughs that were missed on intraoperative fluoroscopy and direct visualization. Therefore, 100% of misplaced screws potentially harmful to nerve roots were identified on direct visualization. Eighty percent occurred from L2-4. CONCLUSIONS: This study provides evidence that undertapping of pedicles followed by placement of a larger diameter pedicle screw may breech the pedicle cortices. Although the risk is low, the authors recommend direct visualization of the pedicle walls during screw placement to identify caudad, medial, and cephalad breeches. This technique is for open laminectomies and should be added to the armamentarium of other techniques and not as a replacement.