Vaccaro Alexander R, Yuan Philip S, Smith Harvey E, Hott Jonathon, Sasso Rick, Papadopoulos Stephen
Department of Orthopaedic Surgery, Spine Fellowship Program, Thomas Jefferson University Hospital/Rothman Institute, Philadelphia, Pennsylvania 19107, USA.
J Spinal Cord Med. 2005;28(4):308-13. doi: 10.1080/10790268.2005.11753825.
Image guidance provides additional anatomic information to the surgeon, which may allow more accurate insertion of spinal implants. Imprecise placement of anterior thoracic screws places the spinal cord and paraspinal structures at risk for injury. Image guidance may afford a safety benefit to patients when anterior thoracic screws are required in the setting of spinal stabilization after trauma.
To compare the accuracy of anterior thoracic screw placement using standard fluoroscopy, computer-assisted fluoroscopic image guidance, Iso-C3D image guidance, and electromagnetic fluoroscopic image guidance.
A surgical simulation study in human cadaver spine specimens.
After an open thoracotomy approach, anterior thoracic screws were placed by experienced spine surgeons using 4 different image-guided techniques in 4 human cadaver thoracic spines. Screws were placed in the 9th, 10th, and 11th thoracic vertebrae of each specimen. The specimens were then examined with thin-cut computed tomography (CT) scans, and with sagittal and coronal reconstructions. Measurements included the distance of the screw from the spinal canal, the angle of the screw path in relation to a perpendicular to a line that bisects the spinous process, and the angle of screw divergence from the superior endplate.
There was no evidence of spinal canal penetrance with any of the image-guided techniques used to place anterior thoracic vertebral body screws. Screws inserted with standard fluoroscopy tended to aim anterolaterally by 18 degrees. The image-guidance systems allowed more accurate placement of anterior thoracic screws in the transverse plane compared with standard fluoroscopy. There was no statistically significant difference in coronal plane screw angulation (angle of divergence with the superior endplate) between any of the imaging methods.
Spinal image-guidance systems may allow spine surgeons to place anterior thoracic screws more precisely, particularly in the axial plane. The improved accuracy of spinal implant insertion could ultimately provide a benefit to patient safety, especially in the setting of malaligned vertebral bodies after trauma.
图像引导为外科医生提供了额外的解剖信息，这可能有助于更准确地植入脊柱植入物。胸段前路螺钉放置不精确会使脊髓和椎旁结构面临受伤风险。在创伤后脊柱稳定需要植入胸段前路螺钉时，图像引导可能会给患者带来安全益处。
比较使用标准荧光透视、计算机辅助荧光透视图像引导、Iso-C3D图像引导和电磁荧光透视图像引导放置胸段前路螺钉的准确性。
在人体尸体脊柱标本上进行的手术模拟研究。
采用开胸手术入路后，经验丰富的脊柱外科医生使用4种不同的图像引导技术在4具人体尸体胸段脊柱上放置胸段前路螺钉。在每个标本的第9、10和11胸椎上放置螺钉。然后对标本进行薄层计算机断层扫描（CT）以及矢状面和冠状面重建检查。测量内容包括螺钉与椎管的距离、螺钉路径相对于垂直平分棘突的线的角度以及螺钉与上终板的发散角度。
使用任何一种图像引导技术放置胸段椎体螺钉均未出现椎管穿透的迹象。使用标准荧光透视插入的螺钉往往向前外侧倾斜18度。与标准荧光透视相比，图像引导系统能使胸段前路螺钉在横断面上的放置更准确。在任何成像方法之间，冠状面螺钉角度（与上终板的发散角度）无统计学显著差异。
脊柱图像引导系统可能使脊柱外科医生更精确地放置胸段前路螺钉，尤其是在轴位平面。脊柱植入物插入准确性的提高最终可能会给患者安全带来益处，特别是在创伤后椎体排列不齐的情况下。
