三维虚拟图像导航技术在脊柱椎弓根螺钉固定中的应用☆

背景：近年来经椎弓根螺钉固定技术显著提高了脊柱固定强度和融合效率,但是椎弓根螺钉置入位置不佳可能损害脊髓和神经引起严重并发症。 目的：评估置入前CT扫描三维虚拟图像导航技术在脊柱椎弓根螺钉固定中的应用价值。 设计、时间及地点：前瞻性、随机对照观察,于2006-01/2008-12在中国医学科学院北京协和医院骨科完成。 对象：纳入因脊柱疾病行椎弓根螺钉固定的患者95例,导航组45例,常规组50例。 方法：将95例患者按随机数字表法分为2组,导航组术中在计算机导航技术辅助下置入椎弓根螺钉,常规组采用传统的解剖标志法结合术中透视定位置入椎弓根螺钉。 主要观察指标：比较2组间螺钉钉道准备时间、螺钉位置优良率及螺钉置入后并发症的发生率。 结果：导航组中36例患者共置入椎弓根螺钉206枚,优良率96.1%;有9例患者因故未能行导航。常规组50例患者共置入椎弓根螺钉285枚,优良率100.0%,无位置差的螺钉。2组患者的螺钉位置优良率差异无显著性意义(P > 0.05)。导航组的钉道准备时间显著长于常规组[(360±22),(56±8) s,P < 0.01]。2组患者螺钉置入后均无并发症发生。 结论：与传统解剖标志定位法相比,应用置入前CT扫描三维虚拟图像导航技术置入椎弓根螺钉的精度无明显差异,且延长了手术时间,其在脊柱椎弓根螺钉固定中的应用价值有限。     

术中CT辅助下椎弓根螺钉置入的精确性和安全性评估

目的 评估术中CT辅助下椎弓根固定技术的安全性和准确性。方法 回顾性分析2014年5月至2015年5月术中CT辅助下椎弓根固定手术治疗的39例脊柱脊髓疾病患者的临床资料,其中脊柱脊髓损伤6例,颅颈交界区畸形6例,脊柱退行性变14例,脊柱脊髓肿瘤13例;术后应用Gertzbein-Robbins分级评价螺钉植入的精确性。结果 椎弓根螺钉固定总数为112枚,术中根据CT影像进行位置修正的螺钉共38枚;其中脊柱脊髓损伤23枚,颅颈交界区畸形8枚,脊柱退行性变40枚,脊柱脊髓肿瘤41枚;颈椎 23枚,胸椎48枚,腰椎41枚。根据Gertzbein-Robbins分级0级105枚,1级5枚,2级2枚。术后发生切口感染4例、脑脊液漏2例、神经损伤1例,未发生与螺钉植入直接相关的并发症,也无二次翻修病例。结论 术中CT能够帮助术者在术中发现位置不良的椎弓根螺钉并对其进行修正,提高椎弓根螺钉植入固定术的精确性和安全性。     

神经导航技术在脊柱固定手术中的应用(附16例报告)

目的探索使用神经导航技术进行脊柱内固定。方法在神经导航辅助下,对16例患者置入70根椎弓根(侧块)螺钉。通过术后X线摄片核实椎弓根螺钉置入的准确性。结果置入的70根椎弓根(侧块)螺钉长度和直径选择合适,其中68根(97·1%)固定位置及方向准确;早期曾有1根穿出至椎体前方(<1mm),未作处理;1根穿出至椎间盘,经翻修后固定情况良好。无神经和血管损伤症状。结论使用神经导航技术,可以前瞻性地判断置入椎弓根(侧块)钉的大小、位置,实时监测置入过程,提高置入的准确性和安全性。术中脊柱影像三维重建及注册配准对神经导航的准确性有较大影响。     

空间“十”字配准脊柱手术机器人导航方法

背景：现有用于椎弓根置入的脊柱手术机器人都要依赖计算机辅助导航系统进行定位和姿态控制，这样计算机辅助导航系统的不足在它们身上都会有体现。包含计算机辅助导航系统的手术机器人，不仅构成复杂，椎弓根置入的精度也难以进一步提高。 目的：探索空间“十”字配准导航方法，控制自主研制的脊柱手术机器人进行更为精准、高效和安全的椎弓根置入。 方法：将依据CT测量值设置的机器手的2枚导针置于两椎弓根中心轴线置入点上并通过X射线正侧位透视确定。令X射线设备的中心投照线先后与2枚导针的中心轴线重合，再从椎弓根轴位进行投照，使体外与体内“十”字配准，定位椎弓根峡部中心点(以下简称中心点)。依据“两点定一线”的原理，使导针通过两椎弓中心轴线置入点和椎弓根峡部中心点，脊柱导航手术机器人即可沿椎弓根中心轴线准确置入。依据规划置入点和置入线相应偏离两椎弓中心轴线置入点的距离和椎弓根中心轴线的角度，完成上述两点的确定或定位后，重新设置两导针中心轴线针尖水平之间的距离及夹角，同样“十”字配准后即可按规划路径准确置入。 结果与结论：“十字配准、两点一线”的导航原理可引导脊柱手术机器人沿椎弓根中心轴线或规划路径准确置入，从而为脊柱手术机器人确定了新的、更为准确高效的导航方法。     

O形臂导航辅助经皮椎弓根螺钉内固定的初步应用

目的探讨O形臂导航辅助经皮椎弓根螺钉内固定的准确性与安全性。方法回顾性分析7例经皮椎弓根螺钉内固定病人的临床及影像学资料。病人均在置钉结束后行O形臂系统3D扫描,按照Gertzbein-Robbins分级评估置钉的准确性。结果 7例病人在O形臂导航辅助下共置入29枚椎弓根螺钉,其中Gertzbein-Robbins分级A级23枚(79.31%),B级4枚(13.79%),C级1枚(3.45%),E级1枚(3.45%)。手术共置入29枚克氏针,其中1枚(3.45%)突破椎体前缘。术中无关节突关节受到破坏。1例出现置钉相关神经并发症行再次手术调整椎弓根螺钉。随访(8.29±2.43)个月,无钉棒置入后相关并发症。结论 O形臂导航辅助经皮椎弓根螺钉内固定具有较高的准确性及安全性。     

神经导航在脊柱固定手术中的应用

目的：探讨应用神经导航系统进行椎弓根螺钉植入的优越性及近期疗效。方法在神经导航辅助下,对17例病人植入76枚椎弓根螺钉,记录单个椎体注册时间、钉道准备时间、术中出血量、术中“C”型臂照射次数、导航精度、术中螺钉重植次数及术后并发症;术后行CT检查评价椎弓根螺钉位置。结果平均单个椎体注册时间（6.3±2.1） min,平均钉道准备时间（2.6±1.3） min,平均术中出血量（253±70） ml;平均“C”型臂照射次数（3.5±0.5）;平均导航精度（0.9±0.1） mm。根据Richter法评估螺钉植入位置：优70枚,良5枚,差1枚;优良率98.68%。术中重植螺钉4枚,重植率5.26%。10例病人随访3～7个月,均无明显神经系统阳性体征。结论在神经导航辅助下,术者可以实时监测螺钉植入过程,前瞻性地判断植入椎弓根螺钉的大小、位置,使椎弓根螺钉植入有较高的准确性和安全性。     

无框架脊柱导航手术机器人腰椎弓根标准轴位引导置针

背景：腰椎弓根螺钉内固定具有很好的生物力学效果,是目前脊柱外科常用的技术。各种各样的经椎弓根引导置入方法,包括计算机辅助导航等,均存在一定的失误率,误置会导致严重后果。 目的：采用自主研发的无框架脊柱导航手术机器人,在椎弓根标准轴位透视引导下置入导针,以期为临床探索一种精准度更高、操作更为简便的经椎弓根穿刺或置入方法。 方法：取6具干燥腰椎体标本(L1~L5),置针前用CT扫描并三维重建后,测量椎弓根中心轴线与椎体自身矢状面的夹角α,以及它与椎体上终板前后缘连线所在平面的夹角β。术中C臂机透视确定腰椎骨标准正位像后,依据α与β角度将其向目标侧椎弓根旋转,进行椎弓根标准轴位投照,遥操作机器人,令导针沿椎弓根近圆环状投影的中心置入。置针后摄椎体侧位像、轴位像观察导针的位置,并行CT扫描测量针道α及β角。 结果与结论：60个椎弓根均成功置入导针,置针后椎体X射线侧位像、轴位像及CT扫描横断面图像显示导针位于椎弓根中心,均未见导针接触或穿破椎弓根骨皮质。提示椎弓根标准轴位投照引导下无框架脊柱导航手术机器人置针,是一种精准度高、可靠安全的新方法,操作简便,并能减少或避免射线暴露。     

椎弓根螺钉对胸腰段椎管内肿瘤术后脊柱稳定性的作用

目的探讨经后正中入路切除胸腰段椎管内肿瘤,同时行椎弓根螺钉内固定植骨融合后,对提高脊柱稳定性的临床疗效.方法采用后正中入路显微手术切除椎管内肿瘤后,应用椎弓根螺钉内固定植骨融合技术进行椎管重建12例,其中肿瘤位于胸段7例,腰段5例.结果肿瘤全切除10例,近全切除2例.术后出现固定区憋胀疼痛3例,经X-线或CT复查证实共5枚螺钉位置欠佳.随访9个月～5年,X-线检查显示手术区植骨全部骨性融合,脊柱稳定.结论采用后正中入路显微手术切除胸腰段椎管内肿瘤后,应用椎弓根螺钉内固定植骨融合技术,能够维持手术后脊柱的稳定性,防止远期后凸畸形的发生.     

术中CT导航在先天性颅颈畸形后路固定中的应用

目的 探讨术中CT与导航系统在先天性颅颈交界区畸形后路固定手术中的应用价值.方法 本组23例患者畸形复杂,男11例,女12例,年龄19～52岁,平均33.5岁.其中3例外院行单纯后颅窝减压术,采用术中CT导航下后路修补枕颈固定术,12例经口齿状突磨除术后,行二期术中CT导航下后路固定术,单纯行术中CT导航下后路减压固定术8例.结果 导航下后路寰椎侧块、枢椎椎弓根螺钉固定7例,经寰枢关节螺钉固定6例,枕颈钉棒系统固定10例,导航验证准确度平均为1.8 mm(0.6 ～2.2 mm).术中发现2例椎弓根螺钉位置不佳,术中调整后CT验证螺钉位置满意.根据术前及术后6个月Nurick分级,21例(91％)患者症状改善1级以上,2例(9％)患者症状无明显改善.本组病例无术中椎动脉及神经功能损伤等并发症.结论 术中CT结合导航系统可以术中及时评价寰枢关节复位情况和植入螺钉的位置及深度,有效地避免了患者二次手术的风险;对于提高手术定位精度、优化手术路径及提高手术成功率等具有重要意义.     

计算机导航辅助下颅颈交界区畸形的内固定治疗

目的探讨计算机导航在颅颈交界区畸形内固定治疗中的应用价值。方法回顾性分析25例颅颈交界区畸形的病例资料,均在计算机导航辅助下行后路寰枢椎钉棒内固定治疗。术后所有病例随访至少12个月,同时采用日本骨科协会(JOA)脊髓功能评分对病人神经功能进行评估。结果术中导航辅助下行寰椎侧块、枢椎椎弓根螺钉固定15例,经寰枢关节螺钉固定6例,经寰枢关节螺钉联合Brooks技术固定4例;所有病人术中予以植骨融合。末次随访JOA评分由术前的(9.25±2.01)分提高至(14.36±1.97)分,差异具有统计学意义(P0.05)。所有病人螺钉置入位置满意,未发生椎动脉及神经损伤等并发症。结论计算机辅助导航为术者实施颅颈交界区畸形内固定手术提供重要帮助,在提高术中螺钉置入准确性、减少手术损伤、降低手术并发症等方面有巨大潜力。     

Posterior thoracic segmental pedicle screw instrumentation: evolving methods of safe and effective placement

The use of pedicle screw instrumentation in the spine has evolved over the last two decades. The initial use of pedicle screws began in the lumbar spine. As surgeons have become more comfortable with the complex anatomy required for accurate screw placement, the use of pedicle instrumentation has evolved to include their use in the thoracolumbar and thoracic spine. The impetus behind their increased use is a result of the many advantages that pedicle screw anchorage offers over traditional hook and rod constructs. Improved deformity correction and overall construct rigidity are two important advantages of pedicle screw instrumentation due its three-column control over the spinal elements. First, pedicle screw instrumentation obviates the need to place instrumentation within the spinal canal with its inherent risk of neurologic injury. Second, the placement of pedicle screws is independent of facet or laminar integrity and thus has been extremely useful in traumatic, neoplastic, and degenerative conditions. The benefits of pedicle screws in the thoracic spine has been tempered by the potential for catastrophic neurological or soft tissue injuries due to the close proximity of these structures. The narrow and inconsistent shape of the thoracic pedicles, especially in spinal deformity, makes their placement technically challenging. As a result, surgeons have employed a number of techniques to ensure the safe and efficacious placement of thoracic pedicle screws. Detailed anatomic landmarks used to determine pedicle location, intraoperative imaging including navigation, and neurophysiological monitoring are some of the techniques currently used by surgeons. The implementation of these techniques and a thorough understanding of the complex three-dimensional anatomy have allowed surgeons to successfully place thoracic and thoracolumbar pedicle screws.     

True accuracy of percutaneous pedicle screw placement in thoracic and lumbar spinal fixation with a CT-based navigation system: Intraoperative and postoperative assessment of 763 percutaneous pedicle screws

PurposeTo investigate intraoperative reinsertion of percutaneous pedicle screw (PPS) with intraoperative CT-based navigation and to evaluate the rate of deviation of PPS at postoperative radiographic examination.MethodsSeven hundred sixty-three screws were inserted in 138 patients. We investigated the rate of occurrence of intraoperative PPS reinsertion after the diagnosis of screw deviation by fluoroscopy and the causes of each screw deviation. The subsequent distribution of PPS deviation was evaluated by postoperative CT. We also assess the difference in variance between the group judged to be PPS misplaced intra-/postoperatively (IOD group/POD group) and appropriate PPS placement (ND group).ResultsAmong all the screws inserted, 10 (1.3%) were diagnosed as being deviated by fluoroscopy during surgery, and 74 (9.7%) screws were found to be deviated at postoperative CT evaluation. We found more pedicle screw mismatch in the POD group than in the ND group (52.7 vs 11.0%, P < 0.001). The distance between the screw and the reference was greater in the IOD group than that in the ND group (1.4 ± 1.2 vs 2.4 ± 1.1 vertebral levels, P = 0.016). In one patient in the IOD group, a motor function deficit was observed postoperatively.ConclusionPPS fixation under intraoperative CT-based navigation did not prevent screw deviation completely. It is necessary to consider errors that occur during surgery and to confirm placement with real-time assistance such as fluoroscopy even in a surgery performed under CT navigation assistance.     

Fijación lumbar posterior empleando el sistema de imagen quirúrgica O-arm: experiencia inicial

ObjectThe use of transpedicular screw fixation has been widely accepted for the treatment of degenerative and traumatic pathology of the lumbar spine. Complications of spinal instrumentation can be serious. Screw misplacement can result in unintended durotomy, nerve root and/or cauda equina injury. In comparison to fluoroscopy-assisted screw placement, computer-assisted image guidance has been shown to achieve overall higher rates of accuracy. The O-arm is able to obtain computed tomography (CT)-type images with multiplanar reconstruction. In this study we evaluated a cohort of patients who underwent posterior lumbar fusion with pedicle screws utilizing the O-arm imaging system.MethodsA retrospective review of 40 consecutive patients who underwent posterior lumbar fusion surgery with O-arm utilization, was performed. The study population included 14 males and 26 females. Age range was 39-85 years with an average of 63.8 years. Twenty one patients had degenerative lumbar stenosis (52.5%) and 19 had spondylolisthesis (47.5%). Intraoperative CT-images were obtained. The mean time for surgery and screw placement was assessed.ResultsA total of 252 pedicle screws were sited using O-arm navigation system, with a mean of 6.3 screws per patient (range 4-10). On the basis of intraoperative CT, 3 screws were redirected, representing a 98.81% accuracy rate.The mean duration of surgery was 157.2 (90-240) minutes and the mean time for screw placement was 7.13 (3.08-15) minutes per screw.Three patients (7.5%) developed superficial wound infections which were treated conservatively. No patients required a return to the operating room because of screw malposition.ConclusionThe use of intraoperative O-arm imaging system with computer-assisted navigation significantly increases the surgical accuracy and safety of pedicle screw placement in lumbar fusion surgery.     

Accuracy and Safety in Pedicle Screw Placement in the Thoracic and Lumbar Spines : Comparison Study between Conventional C-Arm Fluoroscopy and Navigation Coupled with O-Arm? Guided Methods

Objective

The authors performed a retrospective study to assess the accuracy and clinical benefits of a navigation coupled with O-arm® system guided method in the thoracic and lumbar spines by comparing with a C-arm fluoroscopy-guided method.

Methods

Under the navigation guidance, 106 pedicle screws inserted from T7 to S1 in 24 patients, and using the fluoroscopy guidance, 204 pedicle screws from T5 to S1 in 45 patients. The position of screws within the pedicle was classified into four groups, from grade 0 (no violation cortex) to 3 (more than 4 mm violation). The location of violated pedicle cortex was also assessed. Intra-operative parameters including time required for preparation of screwing procedure, times for screwing and the number of X-ray shot were assessed in each group.

Results

Grade 0 was observed in 186 (91.2%) screws of the fluoroscopy-guided group, and 99 (93.4%) of the navigation-guided group. Mean time required for inserting a screw was 3.8 minutes in the fluoroscopy-guided group, and 4.5 minutes in the navigation-guided group. Mean time required for preparation of screw placement was 4 minutes in the fluoroscopy-guided group, and 19 minutes in the navigation-guided group. The fluoroscopy-guided group required mean 8.9 times of X-ray shot for each screw placement.

Conclusion

The screw placement under the navigation-guidance coupled with O-arm® system appears to be more accurate and safer than that under the fluoroscopy guidance, although the preparation and screwing time for the navigation-guided surgery is longer than that for the fluoroscopy-guided surgery.     

Free Hand Pedicle Screw Placement in the Thoracic Spine without Any Radiographic Guidance : Technical Note, a Cadaveric Study

Thoracic pedicle screw fixation techniques are still controversial for thoracic deformities because of possible complications including neurologic deficit. Methods to aid the surgeon in appropriate screw placement have included the use of intraoperative fluoroscopy and/or radiography as well as image-guided techniques. We describe our technique for free hand pedicle screw placement in the thoracic spine without any radiographic guidance and present the results of pedicle screw placement analyzed by computed tomographic scan in two human cadavers. This free hand technique of thoracic pedicle screw placement performed in a step-wise, consistent, and compulsive manner is an accurate, reliable, and safe method of insertion to treat a variety of spinal disorders, including spinal deformity.     

Accuracy of Pedicle Screw Insertion Using Fluoroscopy-Based Navigation-Assisted Surgery : Computed Tomography Postoperative Assessment in 96 Consecutive Patients

Objective

Two-dimensional fluoroscopy-based computerized navigation for the placement of pedicle screws offers the advantage of using stored patient-specific imaging data in providing real-time guidance during screw placement. The study aimed to describe the accuracy and reliability of a fluoroscopy-based navigation system for pedicle screw insertion.

Methods

A total of 477 pedicle screws were inserted in the lower back of 96 consecutive patients between October 2007 and June 2012 using fluoroscopy-based computer-assisted surgery. The accuracy of screw placement was evaluated using a sophisticated computed tomography protocol.

Results

Of the 477 pedicle screws, 461 (96.7%) were judged to be inserted correctly. Frank screw misplacement [16 screws (3.3%)] was observed in 15 patients. Of these, 8 were classified as minimally misplaced (≤2 mm); 3, as moderately misplaced (2.1-4 mm); and 5, as severely misplaced (>4 mm). No complications, including nerve root injury, cerebrospinal fluid leakage, or internal organ injury, were observed in any of the patients.

Conclusion

The accuracy of pedicle screw placement using a fluoroscopy-based computer navigation system was observed to be superior to that obtained with conventional techniques.     

Routine spinal navigation for thoraco–lumbar pedicle screw insertion using the O-arm three-dimensional imaging system improves placement accuracy

Modern image-guided spinal navigation employs high-quality intra-operative three dimensional (3D) images to improve the accuracy of spinal surgery. This study aimed to assess the accuracy of thoraco-lumbar pedicle screw insertion using the O-arm (Breakaway Imaging, LLC, Littleton, MA, USA) 3D imaging system. Ninety-two patients underwent insertion of thoraco–lumbar pedicle screws guided by O-arm navigation over a 27 month period. Intra-operative scans were retrospectively reviewed for pedicle breach. The operative time of patients where O-arm navigation was used was compared to a matched control group where fluoroscopy was used. A total of 467 pedicle screws were inserted. Four hundred and forty-five screws (95.3%) were placed within the pedicle without any breach (Gertzbein classification grade 0). Sixteen screws (3.4%) had a pedicle breach of less than 2 mm (Gertzbein classification grade 1), and six screws (1.3%) had a pedicle breach between 2 mm and 4 mm (Gertzbein classification grade 2). The grade 2 screws were revised intra-operatively. There was no incidence of neurovascular injury in this series of patients. The mean operative time for O-arm patients was 5.25 hours. In a matched control group of fluoroscopy patients, the mean operative time was 4.75 hours. The difference in the mean operative time between the two groups was not statistically significant (p = 0.15, paired t-test). Stereotactic navigation based on intra-operative O-arm 3D imaging resulted in high accuracy in thoraco–lumbar pedicle screw insertion.     

Fluoroscopic versus CT-guided cortical bone trajectory pedicle screw fixation: Comparing trajectory related complications

Cortical bone trajectory (CBT) pedicle screw fixation is an emerging technique for treatment of degenerative spine disease which requires either intraoperative fluoroscopy or intraoperative CT guidance (iCT). To date, there has been no direct comparison of these two navigation modalities; here we compare fluoroscopic versus iCT navigation for CBT pedicle screw fixation. We retrospectively reviewed all patients who underwent CBT screw fixation with either fluoroscopic or iCT guidance for lumbar degenerative disease by the senior author. Trajectory-related complications such as medial or lateral breach were compared on postoperative CT, in addition to the incidence of trajectory-related dural tear. We also compared general surgical complications such as postoperative infection and decompression related durotomies. Thirty-eight patients (19 fluoroscopic, 19 CT-guided) who underwent placement of 182 cortical screws (88 fluoroscopic, 94 CT-guided) were identified. In terms of trajectory-related complications, the iCT cohort had fewer medial breaches (1/94) compared to the fluoroscopic cohort (6/88) (p = 0.05). Each group had one lateral breach (p = 0.73). There was one case of CSF leak from screw placement in the fluoroscopic cohort, but none in the iCT cohort (p = 0.48). Overall, there were eight trajectory-related complications in the fluoroscopic cohort versus two in the iCT cohort (p = 0.04). Our data suggests statistically significant decreased trajectory-related complications with iCT-guided CBT screw fixation as compared to fluoroscopically guided. In terms of general surgical complications, while we observed increased postoperative infections in our fluoroscopic cohort, there was no statistically significant difference.