双平面骨科机器人辅助骶髂关节螺钉置入系统精度测试及尸体应用的研究

目的 测试双平面骨科机器人辅助骶髂关节螺钉置入系统的定位精度,探讨应用双平面骨科机器人系统辅助骶髂关节螺钉置入的临床可行性. 方法 本研究包括系统定位精度实验和尸体应用实验两部分内容.①在导航机器人的底板上固定两根尖克氏针,测量其尖端的坐标真值.应用机器人导航系统得到其坐标的计算值,然后计算测量真值与计算值之间的距离作为系统的定位误差.实验共测量10组数据,得出精度结果 .②在原有对4具尸体骨盆标本置入12枚骶髂关节螺钉实验的基础上,对一具新鲜成年男性尸体进行机器人辅助骶髂关节螺钉置入的临床模拟手术,在其一侧S1椎体内置入2枚螺钉.通过透视和CT图像来评价螺钉的置入位置,同时记录手术时间和透视次数,作为临床评价指标. 结果 通过定位精度实验,本系统的定位精度在2 mm以内,可以满足临床应用的需要.术中导针置入位置与规划螺钉位置有极佳的一致性.术后的透视及CT图像显示,2枚骶髂关节螺钉均位于S1"安全区"内.从采集图像完成到螺钉置入的手术操作时间:第一枚螺钉用时10′36″,第二枚螺钉用时6′48″.置入2枚螺钉(包括术中和术后验证)共透视11次. 结论 本系统能够精确而高效地辅助骶髂关节螺钉置入,并且在提供精确导航的同时,大大减少了术中对患者和手术人员的辐射伤害.     

双平面骨科机器人系统辅助骶髂关节螺钉置入的实验研究

目的本研究应用双平面骨科机器人系统进行尸体骨骨盆骶髂关节螺钉置入的实验研究,评估该系统的安全性和有效性。方法双平面骨科机器人系统是由北京航空航天大学和北京积水潭医院联合开发的一种基于术中X线图像的手术导航系统。在该系统辅助下对4具尸体骨骨盆进行骶髂关节螺钉置入,共12枚空心钉,均置入S1。作为对比,由同一位医生操作,应用传统方法在C型臂透视控制下对模型骨盆进行骶髂关节螺钉置入,同样为12枚空心钉。记录从采集图像到置入空心钉导针所需透视的次数、透视累计时间及操作时间,并进行统计学分析。置入骶髂关节螺钉后,通过目测、透视和锯开骶骨直接测量的方法检查螺钉的位置。结果在机器人导航辅助下,置入一枚导针的平均透视次数是2.5次,平均透视累计时间为1.5s,平均操作时间为253s;12枚骶髂关节螺钉均在安全区内。在透视控制下徒手操作,置入每枚导针的平均透视次数是20.3次,平均透视累计时间为13.7s,平均操作时间为246s;12枚骶髂关节螺钉中,两枚螺钉误置。应用双平面骨科机器人系统辅助操作的透视次数和透视累计时间少于徒手操作,二者差异有显著性意义(P<0.05)。而操作时间二者差异无显著性意义(P>0.05)。结论双平面骨科机器人系统为骶髂关节螺钉置入提供精准的空间定位和稳定的路径导航,而这一切都在短短的数分钟之内完成,具备极好的安全性和高效性,并使患者和医生受到的X线照射量显著减少。目前的应用结果鼓舞我们进一步的临床实验应用。     

术中实时三维导航下经皮骶髂关节螺钉固定术的初步探讨

目的 探讨基于术前CT扫描的术中实时三维导航技术应用于经皮骶髂关节螺钉置入术的可行性. 方法 术前沿着5具正常骨盆标本髂骨翼各置入1枚钛钉后行CT扫描.将扫描数据导入SuperImage软件完成骨盆的三维重建.将三维模型导入导航软件中,获得钛钉标识点在三维虚拟空间的坐标,并规划骶髂关节螺钉置入的安全路径.术中通过导航探针,获取钛钉的实际空间坐标,并与虚拟标识点进行配准;通过导航系统实时跟踪术中骨盆及手术器械的空间位置.在实时三维导航下按照虚拟规划的安全路径,在5具骨盆标本上各完成1枚经皮骶髂关节螺钉的置入,并记录手术操作时间.术后行骨盆CT扫描及三维重建,观察螺钉的位置,并与术前规划结果进行对比. 结果 在5具正常骨盆标本上按照术前虚拟规划的路径各顺利置入1枚骶髂关节螺钉.术后CT扫描显示5枚螺钉位置均满意,与术前虚拟规划结果基本一致.手术操作时间为19～ 23 min,平均21.6 min. 结论 术中实时三维导航技术充分利用术前虚拟规划信息,术中螺钉置入精度高,且无需X线透视,操作流程简单、快捷,在经皮骶髂关节螺钉固定术中具有良好的可行性.     

经皮空心螺钉固定治疗创伤性骶髂关节脱位

目的 介绍一种治疗外伤性骶髂关节脱位的微创手术复位及固定方法。方法 在C臂X线机引导下，用空心螺钉将髂骨与骶骨固定。结果 18例患者均复位满意，术后复查无一例发生再移位。随访6～18个月，疗效满意。结论 经皮空心螺钉治疗骶髂关节脱位是一种可以最大限度减少创伤，减少卧床时间的新型手术方法。该方法简单易行，可作为早期治疗此类创伤的常规方法。     

Placement of C2 laminar screws using three-dimensional fluoroscopy-based image guidance

The use of C2 laminar screws in posterior cervical fusion is a relatively new technique that provides rigid fixation of the axis with minimal risk to the vertebral artery. The techniques of C2 laminar screw placement described in the literature rely solely on anatomical landmarks to guide screw insertion. The authors report on their experience with placement of C2 laminar screws using three-dimensional (3D) fluoroscopy-based image-guidance in eight patients undergoing posterior cervical fusion. Overall, fifteen C2 laminar screws were placed. There were no complications in any of the patients. Average follow-up was 10 months (range 3–14 months). Postoperative computed tomographic (CT) scanning was available for seven patients allowing evaluation of placement of thirteen C2 laminar screws, all of which were in good position with no spinal canal violation. The intraoperative planning function of the image-guided system allowed for 4-mm diameter screws to be placed in all cases. Using modified Odom’s criteria, excellent or good relief of preoperative symptoms was noted in all patients at final follow-up. Eric W. Nottmeier, MD is a paid consultant for BrainLAB.     

Standard multiplanar fluoroscopy versus a fluoroscopically based navigation system for the percutaneous insertion of iliosacral screws: a cadaver model

OBJECTIVES: To compare the safety and efficiency of standard multiplanar fluoroscopy (StdFluoro) and virtual fluoroscopy (VirtualFluoro) for use in the percutaneous insertion of iliosacral screws. DESIGN:: Human cadaver study comparing 2 imaging modalities during iliosacral screw insertion; imaging randomized from side to side. SETTING: Bioskills laboratory in a medical school. PARTICIPANTS: Twenty-nine embalmed whole human cadavers without prior hip or pelvic surgery. INTERVENTION: Iliosacral screws were inserted into the S1 bodies using a percutaneous insertion technique. Screws were inserted on one side using StdFluoro, and on the other side, screws were placed using VirtualFluoro. MAIN OUTCOME MEASUREMENTS: Time necessary for imaging preparation, screw insertion, and actual fluoroscopy were recorded. Accuracy and safety of screw placement was assessed using computed tomography and an anatomic dissection of the pelvis. RESULTS:: Fifty-six of 58 iliosacral screws were placed within the desired bony corridor of the posterior pelvis. One screw placed using each method was inserted erroneously, but both were relatively minor deviations. There were no obvious injuries to major vessels or nerve roots. The total surgical time required for preparation of imaging and screw insertion averaged 7.3 minutes using StdFluoro and 6.7 minutes using VirtualFluoro (P = 0.4). Although the time necessary for screw insertion using VirtualFluoro averaged only 3.5 minutes, compared to 7.0 minutes for StdFluoro (P < 0.05), this time savings was offset by that required for application and calibration of tracking devices when using VirtualFluoro. The average fluoroscopy time using StdFluoro method was 26 seconds, whereas that for the VirtualFluoro was only 6 seconds (P < 0.01). CONCLUSIONS: Most of the percutaneous iliosacral screws were safely inserted using StdFluoro and VirtualFluoro, and total surgical times were similar using both methods. As VirtualFluoro continues to evolve, improved efficiency in operative times may be expected. Currently, the most beneficial aspect of using VirtualFluoro during the insertion of percutaneous iliosacral screws appears to be significantly decreased use of fluoroscopy when compared to StdFluoro.     

Pedicle screw insertion: computed tomography versus fluoroscopic image guidance

Computed tomography image-guided surgery (CTGS) clearly improves the accuracy of pedicle screw insertion. Recent reports claim that a fluoroscopy-guided system (FGS) offered high accuracy and easy application. However, the superiority of either technique remains unclear in clinical application. This study compares the accuracy of pedicle screws installed using CTGS with that of screws installed using FGS. Seventy-four screws inserted using FGS in 13 patients and 76 screws inserted using CTGS in 11 patients were compared. The study population included ten cases of vertebral fracture, five cases of degenerative spondylolisthesis, three cases of spondylolytic spondylolisthesis, two cases of tuberculous spondylitis, two cases of failed earlier back surgery and two case of ankylosing spondylitis with pseudarthrosis. The installed vertebral levels ranged from T8 to S1. Screw positions were assessed with postoperative radiographs and computed tomography. Sixty-nine (93.2%) screws were correctly placed in the FGS group, and seventy-three (96.1%) screws were correctly placed in the CTGS group (P=0.491). The results indicated that both image-guided systems offer high accuracy. However, the fluoroscope image-guided system could be considered the primary tool for lower thoracic and lumbosacral pedicle placement because it enables real-time navigation and does not require a preoperative CT scan.     

Fluoroscopic positioning of sacroiliac screws in 88 patients

BACKGROUND: Fluoroscopic placement of guided sacroiliac screws is a well-established method of fixation of the posterior pelvic ring, leading to biomechanical results similar to an intact pelvic ring. The main problem remains the risk of neurologic injury resulting from the penetration of the intervertebral root or the vertebral canal. METHODS: Eighty-eight patients in whom the posterior pelvic ring was stabilized for several indications were reviewed retrospectively. On perioperative and direct postoperative radiographs and postoperative computed tomographic (CT) scans, positioning was scored for 285 screws and compared with clinical results. RESULTS: Depending on the type of imaging (radiography or CT scan), only 2.1% to 6.8% of the screws showed malpositioning. In several cases, the malpositioned screws did not cause any complaints. Postoperative radiographs did not show any additional value above perioperative radiographs in predicting malpositioning. Seven of 88 patients had neurologic complaints and underwent reoperation. All complaints resolved completely, and no permanent neurologic damage occurred. Positioning both sacroiliac screws in the first vertebral body had a significantly lower rate of neurologic complaints compared with the lower screw in the second vertebral body. CT scanning was able to predict neurologic complaints most accurately. CONCLUSION: Percutaneous sacroiliac screws can be positioned safely, in experienced hands, using perioperative fluoroscopic techniques. A position in the first vertebral body had a significantly lower incidence of neurologic injury compared with a position in the second. In case of postoperative neurologic deficit, only CT scan can predict the clinical outcome. Further research toward improving the perioperative imaging technique must be undertaken.     

Surgical simulation software for insertion of pedicle screws

OBJECTIVE: As the first step toward finding noninvasive alternatives to the traditional methods of surgical training, we have developed a small, stand-alone computer program that simulates insertion of pedicle screws in different spinal vertebrae (T10-L5). METHODS: We used Delphi 5.0 and DirectX 7.0 extension for Microsoft Windows. This is a stand-alone and portable program. RESULTS: The program can run on most personal computers. It provides the trainee with visual feedback during practice of the technique. At present, it uses predefined three-dimensional images of the vertebrae, but we are attempting to adapt the program to three-dimensional objects based on real computed tomographic scans of the patients. The program can be downloaded at no cost from the web site: www.tums.ac.ir/downloads CONCLUSION: As a preliminary work, it requires further development, particularly toward better visual, auditory, and even proprioceptive feedback and use of the individual patient's data.     

骶髂关节螺钉治疗后骨盆骨折脱位

目的 探讨骶髂螺钉内固定术治疗骶髂关节脱位的效果。方法 患者术前进行肠道准备，术中俯卧位，切开显露髂骨外骨面，钻入克氏针，以X线透视正侧位以确定克氏针的位置，将φ6.5mm适当长度的中空松质骨拉力螺钉植入S1.2椎体，术后行康复训练。结果 术后随访6-14个月，7例患者术后无一例骨盆感染，无周围神经损伤，1例骶髂关节复位不佳，移位1.5cm，1枚螺钉误入邻近椎体，幸未产生后遗症。结论 骶髂拉力螺钉固定后骨盆环的技术具有操作较简单，固定可靠，创伤小，失血少，有利于患者康复等优点，骶髂螺钉并发症包括固定失败，置位不当，神经损伤，感染，后骨盆复位不佳等。     

盲置法颈椎弓根螺钉置钉技术的简化与应用

目的探索一种安全、简便、有效的颈椎弓根螺钉置钉方法，便于临床的推广。方法应用颈椎弓根螺钉内固定技术治疗患者11例，共置钉64枚，平均年龄为36岁，其中10例为颈椎外伤，1例为颈椎后纵韧带骨化（连续型）。结果．平均随访16个月，最后随访时X线片显示骨融合良好，无内固定松动或断裂。术中出血量平均约500mL，每枚螺钉置钉所花时间平均约为3min，9例54枚螺钉术后行X线及CT扫描进行椎弓根螺钉位置评价，均置钉成功；2例10枚螺钉术后因经济因素仅行X线检查，螺钉位置良好，无并发症发生。结论在C3-7节段，“一点两垂直法”用于颈椎弓根螺钉的置钉既安全又简便，适用于临床推广，但在术前仍应进行个体化评估，排除手术的禁忌。     

Cyclic loading of sacroiliac screws in Tile C pelvic fractures

BACKGROUND: To investigate the stiffness and strength of completely unstable pelvic fractures fixated both anteriorly and posteriorly under cyclic loading conditions, the authors conducted a randomized, comparative, cadaveric study. METHODS: In 12 specimens, a Tile C1 pelvic fracture was created. The authors compared the intact situation to anterior plate fixation combined with one or two sacroiliac screws. In 2,000 measurements, each pelvis was loaded with a maximum of 400 N. The translation and rotation stiffness of the fixations were measured using a three-dimensional video system. Furthermore, the load to failure and the number of cycles before failure were determined. RESULTS: Both translation and rotation stiffness of the intact pelvis were superior to the fixated pelvis. No difference in stiffness was found between the techniques with one or two sacroiliac screws. However, a significantly higher load to failure and significantly more loading cycles before failure could be achieved using two sacroiliac screws compared with one screw. CONCLUSION: Although the combination of anterior plate fixation combined with two sacroiliac screws is not as stable as the intact pelvis, in this study, embalmed aged pelves could be loaded repeatedly with physiologic forces. Given the fact that the average trauma patient is younger and given the fact that the quality (or grip) of the fixation was a significant covariable for longer endurance of the fixation, this suggests that direct postoperative weight bearing could be possible if these results are confirmed in further research.     

髋臼后柱的CT测量及其X线投照角度的探讨

目的 探讨C型臂X线机透视下经皮置入髋臼后柱螺钉的最佳透视角度. 方法 对10具尸体标本的20侧髋臼进行CT扫描,在扫描结果中包含股骨头最大界面的扫描平面内,测量后柱后表面与冠状面的交角(α角)及后柱后表面与髋臼口所在平面的交角(β角). 结果 髋臼后柱后表面与冠状面的交角(α角)为28.2°±2.3°,髋臼后柱后表面与髋臼口所在平面交角(β角)为95.4°±5.3°.结论 当C型臂X线机以平行于后柱后表面的方向进行投照时,球管与冠状面成约30°角,即在闭孔斜位的基础上增加15°,与闭孔斜位投照相比,能更准确地了解螺钉与后柱后表面之间的关系.     

Cervical pedicle screw insertion: assessment of safety and accuracy with computer-assisted image guidance

We used a commercially available computer-assisted image-guidance system for cervical pedicle screw insertion in both the laboratory and in a preliminary clinical setting. Nine plastic cervical spine models (C2-C7) were used in the laboratory test. The StealthStation was used to create the preoperative plan for each screw such that it would be inserted down the center of the pedicle, parallel to the long axis. Using a light-emitting diode-equipped drill guide, 2-mm holes were drilled in 108 pedicles. A total of 108 pedicle holes were drilled. The mean trajectory deviation from the surgical plan in the axial plane was 1.7+/-1.7 degrees (range, 0 to 8 degrees), and the mean deviation of the position of the hole was 1.7+/-0.6 mm (range, 0.1 to 2.9 mm). Eighty-three drill holes (76.9%) were contained within the pedicles, whereas partial cortical perforation was noted in 25 pedicles (23.1%). In the clinical setting, 36 cervical pedicle screws were inserted in nine patients using the image-guided system. Within the limits of imaging artifact, all 36 pedicle screws appear to have been inserted accurately by postoperative computed tomographic examination. No neurologic or vascular complications were encountered.     

S1椎弓根螺钉结合髂骨板间螺钉治疗骶髂关节骨折脱位

目的 探索S1椎弓根螺钉结合髂骨板问螺钉治疗骶髂关节骨折脱位的临床疗效，评价两者结合对骶髂关节骨折脱位的治疗价值。方法 对11例骶髂关节骨折脱位患者用脊柱内固定系统(TSRH)之S1椎弓根螺钉结合髂骨板间螺钉进行固定，该组患者涉及骶髂关节的垂直移位及旋转的骨盆环变形，归于Tile分型的B类或C类骨盆损伤。11例患者均伴有前环损伤，其中9例予以加压钢板(smith nephew)内固定，余2例患者单纯采用后路手术内固定。结果 7例患者垂直移位完全复位，9例旋转畸形纠正，未发现感染及神经损伤等并发症。结论 S1椎弓根螺钉结合髂骨板问螺钉固定技术治疗骶髂关节骨折脱位，可获得即刻稳定性并良好地维持了复位的效果．这一混合技术对于涉及垂直及旋转损伤的骨盆环损伤有稳定的作用。     

自行研制的经皮胸腰椎椎弓根置钉三维定位器应用的可行性实验研究

目的 通过与"徒手"置钉进行比较,探讨自行研制的经皮胸腰椎椎弓根置钉三维定位器辅助在脊柱标本上进行经皮椎弓根穿刺的可行性.方法 对新鲜保留皮肤软组织的脊柱标本2具(32个椎体)行胸腰椎序列CT扫描,使用Mimics 13.1软件确定椎弓根轴心片,测定水平面椎弓根螺钉植入角度(TSA)及矢状面椎弓根螺钉植入角度(SSA).定位皮肤穿刺点,对应调节水平面及矢状面角度指示器刻度指导穿刺.椎弓根随机分为两组:一侧为自行研制的经皮胸腰椎椎弓根置钉三维定位器辅助组(定位器组),对侧为"徒手"置钉组(徒手组).定位器组在定位器及X线辅助下穿刺,徒手组在C型臂影像增强系统辅助下予"徒手"技术穿刺,置入克氏针,C型臂X线机证实穿刺成功.行椎弓根CT扫描,测量2种方法穿刺的实际TSA角及SSA角,将术前测定的椎弓根TSA角及SSA角与术后实际TSA角及SSA角对比,计算偏差率;比较两组的偏差率和X线曝光次数.结果 定位器组和徒手组的穿刺TSA角偏差率平均分别为10.83%±3.41%和19.08%±4.21%,差异有统计学意义(P＜0.05);定位器组和徒手组的穿刺SSA角偏差率平均分别为13.13%±4.37%和21.15%±6.78%,差异有统计学意义(P＜0.05).定位器组和徒手组接受X线辅助的次数平均分别为(3.0±1.2)次和(5.3±1.6)次,差异有统计学意义(P＜0.05).结论 与"徒手"置钉相比,应用自行研制的经皮胸腰椎弓根置钉三维定位器可有效提高手术准确度、降低手术难度、减少X线暴露.

Abstract：

Objective To test a self-designed 3-D guiding instrument for percutaneous insertion of thoracolumbar pedicle screws in cadaveric vertebrae. Methods Two fresh cadaveric vertebral specimens with skin and soft tissue were used first for standard CT lateral scanning ofT1 to L4.Software Mimics13.1 was used to create axial images of pedicles of vertebral arch.The points of percutaneous insertion of thoracolumbar pedicle screws,transverse screw angles (TSA) and sagittal screw angles (SSA) were measured.Thirty-two vertebral bodies were divided randomly into 2 equal groups for guiding instrument insertion and manual insertion with the aid of C-arm fluoroscopy.The quality of insertion was evaluated by postoperative CT scans.Angular deviations were determined by comparing the preoperative and postoperative TSA and SSA for the 2 groups.X-ray exposures were also compared between the 2 groups. Results The TSA angular deviation rate was ( 10.83 ± 3.41 ) ％ for the guiding instrument insertion group and ( 19.08 ± 4.21 ) ％ for the manual insertion group.The SSA angular deviation rate was (13.13 ±4.37) ％ for the guiding instrument insertion group and (21.15 ± 6.78) ％ for the manual insertion group.The guiding instrument insertion group needed 3.0 ± 1.2 X-ray exposures while the manual insertion group had 5.3 ± 1.6 X-ray exposures.All the differences were statistically significant. Conclusion The 3-D guiding instrument can facilitate the percutaneous insertion of the thoracolumbar pedicle screws by improving operation accuracy and reducing operation difficulty and X-ray exposures as well.     

The lateral sacral triangle--a decision support for secure transverse sacroiliac screw insertion

Sacroiliac (SI) screw fixation represents an effective method to stabilise pelvic injuries. However, to date neither reliable radiological landmarks nor effective anatomical classifications of the sacrum exist. This study investigates the influence of variability in sacral shape on secure transverse SI-screw positioning. Furthermore, consistent correlations of these anatomical conditions are analysed with respect to standard planar pelvic views.For shape analysis, 80 human computed tomography data sets were segmented with the software Amira 4.2 to obtain 3D reconstructions. We identified anatomical conditions (ACs) according to the extent of the effect on the bony screw pathway. Subsequently, the pelvis was spatially aligned using representative bone protuberances in order to create standard Matta projections. In each view, the ACs were described in terms of distance from bone landmarks.Three-dimensional shape analysis revealed the height of the pedicular isthmus (PH) as the limiting variable for secure screw insertion. The lateral and outlet views allowed an orthogonal projection of PH. In the lateral view, the ratio of the lateral sacral triangle framed by the S1 body height and width showed a high correlation to PH (p = 0.0001). A boundary ratio of 1.5 represented a reliable variable to determine whether or not a screw can be inserted (positive predictive value: 97%). In the outlet view, the distance between the S1 endplate and the SI joint top level (EJ) strongly correlated with PH (p = 0.0001). With EJ ≤ 0 mm, screw insertion was possible in all cases (100%).SI-screw insertion requires a well-planned procedure. Orientation of the sacral pedicle is of extreme relevance. A narrow sacroiliac channel and high sacral shape variability limit secure screw placement. However, no determining parameters exist, allowing accurate prediction of secure screw insertion based on X-rays or fluoroscopy.The lateral sacral triangle in the lateral view represents a simple and accurate preoperative method of support for the surgeon's decision to undertake this procedure. No additional technical effort is necessary. A boundary ratio of 1.5 predicts a sufficient bone stock for at least one 7.3 mm screw. Furthermore, the evaluation of the outlet projection can be used to assess the safety of the operation. Basically, a preoperative lateral pelvic image should be mandatory.