Freehand Pedicle Screw Placement Using a Universal Entry Point and Sagittal and Axial Trajectory for All Subaxial Cervical, Thoracic and Lumbosacral Spines.
- 作者列表："Zhang ZF
OBJECTIVE:Existing techniques of freehand pedicle screw placement primarily focus on various entry points with or without axial trajectory. The objective of this paper is to propose a universal entry point and sagittal and axial trajectory for all subaxial cervical, thoracic and lumbosacral spines freehand pedicle screw placements, and to report the results from a single-surgeon clinical experience with freehand pedicle screw placement. METHODS:Two spine vertebrae specimens and 20 cases of three-dimensional (3D) reconstructions of spine CT images were used for observation of the entry point and sagittal and axial trajectory. The author retrospectively reviewed a total of 610 consecutive patients who underwent open, freehand pedicle screw fixation using a universal entry point and sagittal and axial trajectory for all subaxial cervical, thoracic and lumbosacral spine placements, during an 8-year period from January 2010 to December 2017. The junction of the lateral margin of the superior articulating process and the transverse process for the thoracic and lumbosacral spines, or lateral mass for the subaxial cervical spine, was determined. The entry point was chosen at 1 mm, 2 mm, and 3 mm (2 mm on average) caudally and medially to this junction for subaxial cervical, thoracic and lumbosacral spines placements, respectively. Both sagittal and axial trajectories were perpendicular to the sagittal and axial planes of the laminae of the isthmus. Among them, 68 patients underwent postoperative computed tomography (CT) scans, including 26 cervical cases, 19 scoliosis thoracic cases, 10 non-scoliosis thoracic cases, 8 lumbar cases, and 5 sacral cases. Placements of pedicle screws were assessed using CT data and outcome-based classifications systems. RESULTS:After placing the iron scurf at the junction of the lateral margin of the superior articulating process and the transverse process, the present universal entry point was located at 1 o'clock or 11 o'clock of the pedicle's axial view. After inserting the 2.5 mm Gram needle or the pedicle virtual pin tracts according to the entry point and sagittal and axial trajectory described above, the presented trajectory was located in the pedicle's axial trajectory as in the described technique. A total of 766 pedicle screws were placed in 68 CT scan patients with a 99% accuracy rate in the non-kyphoscoliosis group and 92% in the kyphoscoliosis group. CONCLUSIONS:Freehand pedicle screw placement based on the universal entry point and sagittal and axial trajectory for all subaxial cervical, thoracic and lumbosacral spines can be performed with acceptable safety and accuracy.
目的: 现有的徒手椎弓根螺钉置入技术主要集中在有或没有轴向轨迹的各种入口点。本文的目的是提出一个通用的入口点以及矢状和轴向轨迹，用于所有轴下颈椎、胸椎和腰骶椎徒手椎弓根螺钉置入，并报告单外科医生徒手椎弓根螺钉置入临床经验的结果。 方法: 采用2个脊柱椎体标本及20例脊柱CT图像三维重建，观察其进入点及矢状面、轴向轨迹。作者回顾性分析了2010年1月至2017年12月8年间共610例连续接受开放、徒手椎弓根螺钉固定的患者，这些患者使用通用入口点以及矢状面和轴向轨迹对所有轴下颈椎、胸椎和腰骶椎置入进行固定。确定胸椎和腰骶椎上关节突外侧缘与横突的交界处，或下颈椎侧块。选择1 mm、2 mm和3 mm (平均2 mm) 的入口点，分别位于该交界处的轴下颈、胸和腰骶椎的尾部和内侧。矢状和轴向轨迹均垂直于峡部椎板的矢状和轴向平面。其中68例患者术后行计算机断层扫描 (CT) 检查，其中颈椎26例，胸椎侧弯19例，非胸椎侧弯10例，腰椎8例，骶骨5例。使用CT数据和基于结果的分类系统评估椎弓根螺钉的放置。 结果: 将铁屑置于上关节突与横突侧缘交界处后，目前通用的进入点位于椎弓根轴位的1点或11点。在根据上述进入点以及矢状和轴向轨迹插入2.5克针或椎弓根虚拟针束后，所呈现的轨迹位于椎弓根的轴向轨迹中，如所描述的技术。68例ct扫描患者共置入766枚椎弓根螺钉，非脊柱侧后凸组准确率为99%，脊柱侧后凸组准确率为92%。 结论: 基于通用进入点以及矢状和轴向轨迹的徒手椎弓根螺钉置入术可用于所有轴下颈椎、胸椎和腰骶椎棘突，具有可接受的安全性和准确性。
METHODS:OBJECTIVES:The aim was to evaluate the image quality and sensitivity to artifacts of compressed sensing (CS) acceleration technique, applied to 3D or breath-hold sequences in different clinical applications from brain to knee. METHODS:CS with an acceleration from 30 to 60% and conventional MRI sequences were performed in 10 different applications in 107 patients, leading to 120 comparisons. Readers were blinded to the technique for quantitative (contrast-to-noise ratio or functional measurements for cardiac cine) and qualitative (image quality, artifacts, diagnostic findings, and preference) image analyses. RESULTS:No statistically significant difference in image quality or artifacts was found for each sequence except for the cardiac cine CS for one of both readers and for the wrist 3D proton density (PD)-weighted CS sequence which showed less motion artifacts due to the reduced acquisition time. The contrast-to-noise ratio was lower for the elbow CS sequence but not statistically different in all other applications. Diagnostic findings were similar between conventional and CS sequence for all the comparisons except for four cases where motion artifacts corrupted either the conventional or the CS sequence. CONCLUSIONS:The evaluated CS sequences are ready to be used in clinical daily practice except for the elbow application which requires a lower acceleration. The CS factor should be tuned for each organ and sequence to obtain good image quality. It leads to 30% to 60% acceleration in the applications evaluated in this study which has a significant impact on clinical workflow. KEY POINTS:• Clinical implementation of compressed sensing (CS) reduced scan times of at least 30% with only minor penalty in image quality and no change in diagnostic findings. • The CS acceleration factor has to be tuned separately for each organ and sequence to guarantee similar image quality than conventional acquisition. • At least 30% and up to 60% acceleration is feasible in specific sequences in clinical routine.
METHODS:BACKGROUND:The main surgical techniques for spontaneous basal ganglia hemorrhage include stereotactic aspiration, endoscopic aspiration, and craniotomy. However, credible evidence is still needed to validate the effect of these techniques. OBJECTIVE:To explore the long-term outcomes of the three surgical techniques in the treatment of spontaneous basal ganglia hemorrhage. METHODS:Five hundred and sixteen patients with spontaneous basal ganglia hemorrhage who received stereotactic aspiration, endoscopic aspiration, or craniotomy were reviewed retrospectively. Six-month mortality and the modified Rankin Scale score were the primary and secondary outcomes, respectively. A multivariate logistic regression model was used to assess the effects of different surgical techniques on patient outcomes. RESULTS:For the entire cohort, the 6-month mortality in the endoscopic aspiration group was significantly lower than that in the stereotactic aspiration group (odds ratio (OR) 4.280, 95% CI 2.186 to 8.380); the 6-month mortality in the endoscopic aspiration group was lower than that in the craniotomy group, but the difference was not significant (OR=1.930, 95% CI 0.835 to 4.465). A further subgroup analysis was stratified by hematoma volume. The mortality in the endoscopic aspiration group was significantly lower than in the stereotactic aspiration group in the medium (≥40-<80 mL) (OR=2.438, 95% CI 1.101 to 5.402) and large hematoma subgroup (≥80 mL) (OR=66.532, 95% CI 6.345 to 697.675). Compared with the endoscopic aspiration group, a trend towards increased mortality was observed in the large hematoma subgroup of the craniotomy group (OR=8.721, 95% CI 0.933 to 81.551). CONCLUSION:Endoscopic aspiration can decrease the 6-month mortality of spontaneous basal ganglia hemorrhage, especially in patients with a hematoma volume ≥40 mL.
METHODS:OBJECTIVE:The primary purpose of this study was to evaluate the effectiveness of a three-dimensional (3D) software tool (smart planes) for displaying fetal brain planes, and the secondary purpose was to evaluate its accuracy in performing automatic measurements. MATERIAL AND METHODS:This prospective study included singleton fetuses with a gestational age (GA) greater than 18 weeks. Transabdominal two-dimensional ultrasound (2DUS) and 3D smart planes images were respectively used to obtain the basic planes of the fetal brain, with five parameters measured. The images, by either two-dimensional (2D) manual or 3D automatic operation, were reviewed by two experienced sonographers. The agreements between two measurements were analyzed. RESULTS:A total of 226 cases were included. The rates of successful detection by automatic display were as high as 80%. There was substantial agreement between the measurements of the biparietal diameter, head circumference and transcerebellar diameter, but poor agreement between the measurements of cisterna magna and lateral ventricle width. CONCLUSIONS:Smart Planes might be valuable for the rapid evaluation of fetal brain, because it simplifies the evaluation process. However, the technology requires improvement. In addition, this technology cannot replace the conventional manual US scans; it can only be used as an additional approach.