青少年脊柱侧凸患者胸椎椎弓根螺钉置入的准确性和安全性评价

目的：探讨青少年脊柱侧凸患者胸椎椎弓根螺钉置入的准确性和安全性，以减少相关手术并发症。方法：32例青少年脊柱侧凸患者术前均对畸形脊柱进行标准俯卧位CT加密扫描，测量进钉点至椎体前缘的深度、进针角度、椎弓根直径和椎体的旋转角度，根据测得数据确定椎弓根螺钉置入的深度和方向，置入螺钉后再行脊柱全长X线片及CT扫描评价置钉的准确性和安全性。结果：32例共置入226枚胸椎椎弓根螺钉，术后CT加密和X线片观察到205枚螺钉（90．7％）完全在椎弓根皮质骨内。10例21枚螺钉（9.3％）发生错置，7枚螺钉（3．1％）偏外，5枚螺钉（2．2％）偏前外侧（其中2枚螺钉靠近节段血管），4枚螺钉（1．8％）偏下，4枚螺钉（1．8％）直径过大导致椎弓根内壁膨胀内移，1枚螺钉（0．4％）误入椎管导致完全性脊髓损伤。T1～T4错置12枚（18．2％），T5～T12错置9枚（6．1％）；凸侧椎根螺钉置入的准确率为93．8％，凹侧为83．1％。结论：脊柱畸形患者术前应常规采用标准俯卧位CT加密扫描，根据扫描图像测得的相关数据可为术中准确置入椎弓根螺钉提供重要参考依据。在青少年脊柱侧凸患者胸椎椎弓根螺钉置入有一定的误置率，螺钉发生错置多见于上胸椎和凹侧．术中应高度重视。     

对徒手置入胸椎椎弓根螺钉的安全性评价

目的：评价徒手置入胸椎椎弓根螺钉的安全性并探讨其置钉方法.方法：372例患者采用徒手方法置入胸椎椎弓根螺钉,记录置入操作中和术后并发症,其中37例患者术后行CT断层扫描检查判断螺钉的位置,记录所有穿透骨皮质螺钉的数目和距离.结果：共徒手置入胸椎椎弓根螺钉2261枚,平均每例患者置入螺钉6.08枚,术中6例次置钉过程中出现脑脊液从钉道中流出,术中和术后未出现神经、血管和内脏损伤等并发症.37例患者术后行CT扫描判断螺钉位置,405枚螺钉中124枚（30.62%）穿透骨皮质,1枚（0.02%）穿透椎弓根内侧壁超过4mm.结论：徒手置入胸椎椎弓根螺钉穿透骨皮质的发生率较高,应该根据每个椎体旋转、倾斜等差异个体化确定置钉位置和方向,操作仔细认真,保证准确、安全、可靠地置入胸椎椎弓根螺钉.     

特发性脊柱侧凸患者胸椎椎弓根的CT测量及其临床意义

目的：测量特发性脊柱侧凸患者胸椎椎弓根的有关数据，探讨其临床应用价值。方法：在30例特发性脊柱侧凸患者术前CT扫描片上测量胸椎椎弓根的宽度、深度、角度、椎体旋转角度等数据，根据所得数据选定置入螺钉的直径、长度．确定置入方向和深度。术后对置入螺钉的胸椎椎弓根节段行CT扫描，判断置钉位置。结果：CT测量的各项数据显示胸椎椎弓根适合椎弓根螺钉的置入。以此为依据术中置入胸椎弓根螺钉共245枚，228枚(93％)置入无误，6枚穿破椎弓根外壁，9枚穿破椎弓根下壁，2枚穿破椎弓根内壁，无神经系统并发症。结论：术前CT扫描测量特发性脊柱侧凸患者的胸椎椎弓根的有关数据可为选择适当长度和直径的螺钉并将其准确置入胸椎椎弓根内提供参考。从而保证螺钉安全置入。     

C型臂X线透视判断上中胸椎椎弓根螺钉位置的可靠性研究

目的：探讨C型臂X线透视判断上中胸椎椎弓根螺钉置入位置的准确性。方法：选用10具成年防腐保存的脊柱标本（T1～T6），根据椎弓根水平面倾斜角用手锥建立螺钉位置偏内（38个）、偏外（36个）、居中（46个）3种模型，分别置入导针和椎弓根螺钉后依次透视正位、侧位、椎弓根轴位、导针轴位、椎弓根螺钉轴位，根据导针和椎弓根钉与椎弓根投影的相互位置关系判断导针和椎弓根钉位置．同时行CT扫描观察椎弓根螺钉位置以及椎弓根内外侧皮质穿透情况．根据CT扫描结果判断C型臂X线图像对椎弓根螺钉置入监测的准确率。结果：120个椎弓根正位透视10枚偏内，其中5枚实际位置良好．未发现偏外者．正确率为35％；侧位透视不能判断偏内及偏外错误；椎弓根轴位透视将5枚居中判为偏内，准确率为95．9％；导针和椎弓根钉轴位透视均将4枚偏外模型判为居中,准确率为96．7％。结论：C型臂X线透视时椎弓根轴位和导针轴位图像能较准确判断椎弓根钉导针位置。     

CT三维重建立体导航引导技术在胸椎弓根钉置入手术中的应用

目的探讨术前CT三维重建立体导航引导技术在胸椎弓根钉置入手术中的应用方法和临床意义。方法2003年5月-2006年5月采用CT三维重建导航对2t例（122枚）胸椎弓根钉置入手术进行立体引导,其中上胸椎38枚,中下胸椎84枚。男13例,女8例;年龄为13—76岁,平均43岁。术中使用C形臂X线机拍摄正侧位X线片,术后行CT扫描以了解椎弓根钉位置情况。结果术后CT椎弓根位置扫描显示：A级109枚（89．3％）B级6枚（4．9％）;C级3枚（2．5％）;D级4枚（3．3％）。结论术前CT三维重建立体导航引导技术使椎弓根钉按预期的路径精确置入,尤其提高了具有挑战性的胸椎椎弓钉置入的安全性和准确性。     

个体化选择脊柱侧凸患者胸椎椎弓根螺钉进钉点的研究

目的:探讨个体化选择脊柱侧凸患者胸椎椎弓根螺钉进钉点对置钉准确性的影响.方法:2006年3月至2008年6月手术治疗脊柱侧凸患者57例,其中青少年特发性脊柱侧凸44例,先天性脊柱侧凸12例,马凡综合征1例.根据患者术前CT设计拟固定胸椎的椎弓根螺钉进钉点并用于指导术中的进钉点选择,术后根据螺钉是否突破椎弓根的皮质壁来判断置钉准确性.结果:全部患者共置入椎弓根螺钉591枚,胸椎417枚,腰椎174枚,术后530枚螺钉的轴线完全位于椎弓根皮质内,准确率为89.7%, 其中胸椎置钉准确率为86.8%(362,417).61枚螺钉的轴线突破椎弓根皮质壁,胸椎55枚,腰椎6枚.55枚偏置的胸椎椎弓根螺钉中52枚螺钉的实际进钉点与术前设计一致,其中19枚钉尖位于椎体内;3枚螺钉为术中实际进钉点选择失误,螺钉轴线突破椎弓根皮质壁的距离均不超过4mm.无脊髓、大血管及脏器损伤等严重并发症发生.结论:个体化选择胸椎椎弓根螺钉进钉点可提高脊柱侧凸患者胸椎置钉的准确率,减少术中进钉点选择失误所致的并发症.     

胸腰椎椎弓根螺钉误置的原因分析及对策

目的 探讨胸腰椎椎弓根螺钉误置的原因及对策。方法 1996-2002年对293例脊柱疾病患者施行椎弓根螺钉内固定术发生的螺钉误置情况进行回顾性总结，分析。结果 293例共置入椎弓根螺钉1256枚，螺钉植入节段错误7例，占2.38%；上胸椎（T2-7）置钉113枚，有11枚螺钉穿破椎弓根皮质，占9.74%；下胸椎（T8-12）置钉261枚，有9枚螺钉穿破椎弓根皮质，占3.45%；腰骶椎置钉882枚，有16枚穿破椎弓根皮质，占1.81%，共计36枚螺钉，占2.87%；螺钉角异常65枚，占5.81%。结论 椎弓根螺钉误置与操作技术，解剖学变异及脊柱病损因素密切相关；良好的手术技巧，术前影像资料的认真观测及术中必要的影像监控是准确置钉的关键。     

术前CT引导胸腰椎椎弓根螺钉置入改良技术

目的:探讨总结以术前CT扫描椎弓根轴心来获得螺钉置入解剖参数引导胸腰段椎弓根螺钉置入的改良方法。方法:使用改良置钉技术对56例脊柱损伤患者置入胸腰椎弓根螺钉242枚,其中男32例,女24例;年龄21～69岁,平均43岁。以术前CT扫描确定椎弓根轴心线,轴心线附近的解剖标志为参照确定螺钉入点,内聚E角、螺钉长度、直径均可在CT椎弓根轴心片上读出,而矢状F角可由X线侧位片上读出或观察脊突线得出。结果:242枚螺钉术后均拍摄椎弓根CT片复查,238枚螺钉完全置入椎弓根内,仅4枚有穿破椎弓根皮质,失误率1.65%,但穿破较小,均无神经根症状。结论:术前CT扫描椎弓根引导胸腰椎椎弓根螺钉的置入是一个较好的改良方法,能有效降低不良置钉率。     

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。     

透视下分步引导上中胸椎椎弓根螺钉安全植入实验研究

目的：探索C形臂X线监测引导上中胸椎椎弓根螺钉植入的的方法,并评定其准确性与安全性。方法：①取6具正常成人T1-T8脊椎骨架标本,分解出单个椎体,导针沿椎弓根轴线进针,分别于进针点、针前端位于椎弓根中部、椎体后缘及椎体前缘皮质下,通过C形臂X线透视,记录、分析椎弓根轴线导针在进针点及不同进针深度时在正侧位透视图像上导针前端的位置,以及相关位置对应关系变化规律。②按上述椎弓根轴线导针C形臂X线透视监测对应位置变化规律,作为C形臂X线透视下分步引导上中胸椎椎弓根螺钉安全植入的方法。取6具T1-T8脊柱标本,C形臂X线机引导下分步植入椎弓根螺钉96枚,然后将脊椎标本作CT扫描,判定椎弓根螺钉位置。结果：根据CT扫描结果,优（椎弓根螺钉安全位于椎弓根内者）90枚,可（螺钉穿破椎弓根内或外侧骨皮质较少,突破在2mm以内者）6枚,差（螺钉穿破椎弓根内外骨皮质较多,突破在2mm以上）0枚。结论：C形臂X线透视下分步引导上中胸椎椎弓根螺钉植入,是一种能提高上中胸椎椎弓根螺钉植入的简单经济、确实可行的方法。     

Inserting pedicle screws in the upper thoracic spine without the use of fluoroscopy or image guidance. Is it safe?

Several studies have looked at accuracy of thoracic pedicle screw placement using fluoroscopy, image guidance, and anatomical landmarks. To our knowledge the upper thoracic spine (T1–T6) has not been specifically studied in the context of screw insertion and placement accuracy without the use of either image guidance or fluoroscopy. Our objective was to study the accuracy of upper thoracic screw placement without the use of fluoroscopy or image guidance, and report on implant related complications. A single surgeon inserted 60 screws in 13 consecutive non-scoliotic spine patients. These were the first 60 screws placed in the high thoracic spine in our institution. The most common diagnosis in our patient population was trauma. All screws were inserted using a modified Roy-Camille technique. Post-operative axial computed tomography (CT) images were obtained for each patient and analyzed by an independent senior radiologist for placement accuracy. Implant related complications were prospectively noted. No pedicle screw misplacement was found in 61.5% of the patients. In the remaining 38.5% of patients some misplacements were noted. Fifty-three screws out of the total 60 implanted were placed correctly within all the pedicle margins. The overall pedicle screw placement accuracy was 88.3% using our modified Roy-Camille technique. Five medial and two lateral violations were noted in the seven misplaced screws. One of the seven misplaced screws was considered to be questionable in terms of pedicle perforation. No implant related complications were noted. We found that inserting pedicle screws in the upper thoracic spine based solely on anatomical landmarks was safe with an accuracy comparable to that of published studies using image-guided navigation at the thoracic level.     

Accuracy and safety of thoracic pedicle screw placement in spinal deformities

OBJECTIVES: To determine the safety of pedicle screw fixation in thoracic spine deformity correction. METHODS: One hundred twelve pedicle screws were surgically placed in 25 patients with degenerative, posttraumatic, and Scheuermann kyphosis and idiopathic and neuromuscular scoliosis. Screw position was evaluated using intraoperative and postoperative radiographs and thin-slice computed tomography. RESULTS: Of the total 112 thoracic pedicle screws that were inserted, 98 screws (87.5%) were fully contained within the cortical boundaries of the pedicle. When comparing proximal screws (T1-T8) with distal screws (T9-T12) and convex placed screws with concave ones, a statistically significant difference in screw placement was evident (P < 0.05). More misplaced screws were seen proximally and on the concave side. Of the 14 malpositioned screws, 2 (1.8%) demonstrated aortic abutment. There were no neurologic deficits, vascular injuries, or mechanical failures recorded. CONCLUSIONS: Placement of thoracic pedicle screws is both feasible and safe.     

应用椎板开窗法置入胸椎椎弓根螺钉的精确性和安全性评估

目的 分析应用椎板开窗法行胸椎椎弓根螺钉置入治疗重度脊柱侧后凸患者的精确性和安全性. 方法 1996年6月至2007年12月,应用椎板开窗法行胸椎椎弓根螺钉置入治疗23例重度脊柱侧后凸患者(A组),其中男性9例,女性14例;年龄13～23岁,平均17.8岁;术前主胸弯冠状面Cobb角平均97.3°,平均后凸角67.4°.作为对照,同期应用非开放法置钉治疗重度脊柱侧后凸患者22例(B组),其中男性7例,女性15例;年龄14～21岁,平均17.2岁;术前主胸弯冠状面Cobb角平均为96.6°,平均后凸角62.1°.两组患者术后均行CT扫描,统计螺钉置入并发症,对螺钉穿透椎弓根皮质骨的CT扫描图像进行联机测量并统计分析.结果 A组和B组各置入胸椎椎弓根螺钉209和201枚,术中发生椎弓根骨折5例和16例,发生硬膜撕裂4例和7例,螺钉错置18枚和45枚.B组螺钉错置率高于A组,差异具有统计学意义(P<0.05).A组上、中胸椎与下胸椎之间、凸侧与凹侧之间,螺钉错置率差异均具有统计学意义(P<0.05).两组均无脊髓及大血管损伤. A和B组经平均3.2年、3.4年随访,术后冠状面和矢状面平均矫正度未见明显丢失.结论 重度脊柱侧后凸胸椎椎弓根螺钉置入技术难度较高,应用椎板开窗法可有效增加螺钉置入精确性和安全性.     

快速成型个体化导航模板辅助胸椎椎弓根螺钉置入可行性研究

[目的]通过尸体标本实验的方法探讨个体化导航模板辅助胸椎椎弓根螺钉置入的准确性及可行性.[方法]对6具胸椎尸体标本进行CT扫描,根据CT扫描资料,利用逆向工程原理及快速成型技术设计制造出个体化导航模板,利用个体化导航模板在尸体标本上辅助置入胸椎椎弓根螺钉,所有螺钉的置入由同一位具有腰椎椎弓根螺钉置钉经验但无胸椎椎弓根螺钉置钉经验的骨科医师进行操作,随后采用大体解剖的方法肉眼观察置钉的准确性;并根据螺钉是否穿破椎弓根、穿出距离及穿破方向进行分级.[结果]共设计制作了72个个体化导航模板辅助置入胸椎椎弓根螺钉144枚,132枚(91.7%)螺钉完全在椎弓根内;12(8.3%)枚螺钉穿破椎弓根,其中2枚螺钉穿破椎弓根内侧壁(穿破距离分别为0.6、0.8 mm),10枚螺钉穿破椎弓根外侧壁(9枚螺钉穿出距离<2 mm,1枚螺钉穿出距离为2.5 mm);没有椎弓根上方、下方及椎体前方穿破的螺钉.所有穿破椎弓根壁的螺钉均在安全可接受的范围内.[结论]快速成型个体化导航模板辅助胸椎椎弓根螺钉置入准确率高,对术者无特别的经验要求,手术操作简单、安全,可避免术中放射性损伤,为胸椎椎弓根螺钉的置入提供了一种新的可行方法,尤其适用于初学者.     

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.     

非影像监视下行脊柱侧凸胸椎椎弓根螺钉置入的临床应用

目的:探讨脊柱侧凸胸椎椎弓根螺钉非影像监视下徒手置入的方法及可行性。方法:57例脊柱侧凸患者行后路椎弓根螺钉系统矫形手术,徒手法置入胸椎椎弓根螺钉。术后常规拍摄脊柱全长X线片,随机选取10例患者行CT扫描观察,了解螺钉置入的准确性。结果:共置入胸椎椎弓根螺钉362枚。术后X线片观察到10枚螺钉偏外,4枚螺钉偏下,其中2枚螺钉引起轻微肋间神经痛,3周后完全缓解。CT观察47枚螺钉有2枚螺钉导致椎弓根内壁膨胀内移,没有相应神经症状。主弯Cobb角术前平均60.4°(32°～121°),术后平均18.3°(1°～70°),平均矫正率71.9%(38.1%～98.0%)。结论:徒手法置入脊柱侧凸胸椎椎弓根螺钉是可行的。     

Accuracy and safety of pedicle screw placement in neuromuscular scoliosis with free-hand technique

It is a retrospective analytic study of 1,009 transpedicular screws (689 thoracic and 320 lumbosacral), inserted with free-hand technique in neuromuscular scoliosis using postoperative CT scan. The aim of paper was to determine the accuracy and safety of transpedicular screw placement with free-hand technique in neuromuscular scoliosis and to compare the accuracy at different levels in such population. All studies regarding accuracy and safety of pedicle screw in scoliosis represent idiopathic scoliosis using various techniques such as free-hand, navigation, image intensifier, etc., for screw insertion. Anatomies of vertebrae and pedicle are distorted in scoliosis, hence accurate and safe placement of pedicle screw is prerequisite for surgery. Between 2004 and 2006, 37 consecutive patients, average age 20 years (9–44 years), of neuromuscular scoliosis were operated with posterior pedicle screw fixation using free-hand technique. Accuracy of pedicle screws was studied on postoperative CT scan. Placement up to 2 mm medial side and 4 mm lateral side was considered within-safe zone. Of the 1,009 screws, 273 screws were displaced medially, laterally or on the anterior side showing that 73% screws (68% in thoracic and 82.5% in lumbar spine) were accurately placed within pedicle. Considering the safe zone, 93.3% (942/1009, 92.4% in thoracic and 95.3% in lumbar spine) of the screws were within the safe zone. Comparing accuracy according to severity of curve, accuracy was 75% in group 1 (curve <90°) and 69% in group 2 (curve >90°) with a safety of 94.8 and 91.2%, respectively (P = 0.35). Comparing the accuracy at different thoracic levels, it showed 67, 64 and 72% accuracy in upper, middle and lower thoracic levels with safety of 96.6, 89.2 and 93.1%, respectively, exhibiting no statistical significant difference (P = 0.17). Pedicle screw placement in neuromuscular scoliosis with free-hand technique is accurate and safe as other conditions.     

Evaluation of electromyographic monitoring during insertion of thoracic pedicle screws

We prospectively studied the use of intercostal EMG monitoring as an indicator of the accuracy of the placement of pedicle screws in the thoracic spine. We investigated 95 thoracic pedicles in 17 patients. Before insertion of the screw, the surgeon recorded his assessment of the integrity of the pedicle track. We then stimulated the track using a K-wire pedicle probe connected to a constant current stimulator. A compound muscle action potential (CMAP) was recorded from the appropriate intercostal or abdominal muscles. Postoperative CT was performed to establish the position of the screw. The stimulus intensity required to evoke a muscle response was correlated with the position of the screw on the CT scan. There were eight unrecognised breaches of the pedicle. Using 7.0 mA as a threshold, the sensitivity of EMG was 0.50 in detecting a breached pedicle and the specificity was 0.83. Thoracic pedicle screws were accurately placed in more than 90% of patients. EMG monitoring did not significantly improve the reliability of placement of the screw.     

Pedicle screw placement in the thoracic spine: a randomized comparison study of computer-assisted navigation and conventional techniques

Objective： To evaluate the accuracy of computer-assisted pedicle screw installation and its clinical benefit as compared with conventional pedicle screw installation techniques.
Methods： Total 176 thoracic pedicle screws placed in 42 thoracic fracture patients were involved in the study randomly, 20 patients under conventional fluoroscopic control （84 screws） and 22 patients had screw insertion under three dimensional （3D） computer-assisted navigation （92 screws）. The 2 groups were compared for accuracy of screw placement, time for screw insertion by postoperative thincut CT scans and statistical analysis by χ^2 test. The cortical perforations were then graded by 2-mm increments： Grade Ⅰ （good, no cortical perforation）, Grade Ⅱ （screw outside the pedicle 〈2 mm）, Grade Ⅲ （screw outside the pedicle 〉2 mm）.
Results： In computer assisted group, 88 （95.65%） were Grade Ⅰ （good）, 4 （4.35%） were Grade Ⅱ （〈2mm）, no Grade Ⅲ （〉2 mm） violations. In conventional group, there were 14 cortical violations （16.67%）, 70 （83.33%） were Grade Ⅰ （good）, Ⅱ （13.1%） were Grade Ⅱ （〈2 mm）, and 3 （3,57%） were Grade Ⅲ （〉2 mm） violations （P〈0.001）. The number （19.57%） of upper thoracic pedicle screws （ T1-T4 ） inserted under 3D computer-assisted navigation was significantly higher than that （3.57%） by conventional fluoroscopic control （P〈0.001）. Average screw insertion time in conventional group was （4.56 ±1.03） min and （2.54 ± 0.63） min in computer assisted group （P〈0.001）. In the conventional group, one patient had pleura injury and one had a minor dura violation.
Conclusions： This study provides further evidence that 3D computer-assisted navigation placement ofpedicle screws can increase accuracy, reduce surgical time, and be performed safely and effectively at all levels of the thoracic spine, particularly upper thoracic spine.