Dept. of Trauma and Reconstructive Surgery, University of Rostock, Schillingallee 35, D 18057 Rostock, Germany.
Injury. 2010 Oct;41(10):996-1001. doi: 10.1016/j.injury.2010.02.006. Epub 2010 Feb 26.
After dorsal stabilisation of vertebral fractures by an internal fixateur the postoperative computed tomography is a standard procedure to control the positions of the pedicle screws, the success of the reposition, the clearance of the spinal canal and to plane an additive secondary ventral stabilisation. An intraoperative scan with a 3D image intensifier may clarify these questions directly after the implantation with the possibility of an immediate correction of the implants. The aim of this study was to find out the optimal point of time to perform an intraoperative 3D scan and if a postoperative computed tomography is dispensable.
Intraoperative 3D scans were carried out on 33 patients with thoracolumbar spine fractures (T11-L5) after bi-segmental fixateur interne montage (Group 1). A matched pair group of 33 patients (Group 2) with a 3D scan after implantation of pedicle screws was built. A postoperative computed tomography of the instrumented spinal section was done in all patients. The following measurements were done in sagittal and axial reconstruction planes and were compared: classification of screw positions, maximal axial diameter of pedicles, cortical perforation of the screws. Additionally in Group 1 the distance between the upper and lower end plates of the injured section, the height of posterior vertebral body wall, the dislocation of the posterior wall and the minimal diameter of the spinal canal were measured.
The intraoperative scoring of pedicle screws positions and the measurement of pedicle width showed in both groups a significant accordance with the computed tomography determinations. The measurements "posterior wall dislocation" and "diameter of spinal canal" were only possible in 24 3D scans and showed a significant difference compared with the CT data. The picture quality in Group 2 was scored significantly better than for Group 1 with the complete assembly of the fixateur.
The ideal point of time for an intraoperative 3D imaging with the present intensifier generation is directly after pedicle screw insertion. The reliable determination of the spinal canal diameter, of posterior wall fragments and of the exact fracture morphology is only possible by postoperative computed tomography.
在通过内置固定器稳定了脊柱骨折的背侧后，术后计算机断层扫描是一种标准程序，用于控制椎弓根螺钉的位置、复位的成功、椎管的通畅程度，并规划附加的二次前路稳定。术中使用三维影像增强器进行扫描可以在植入后直接解决这些问题，并有可能立即纠正植入物。本研究的目的是确定进行术中三维扫描的最佳时间，以及是否可以省去术后计算机断层扫描。
对 33 例胸腰椎骨折（T11-L5）患者（1 组）进行了双节段内置固定器植入后的术中三维扫描。建立了一组 33 例接受椎弓根螺钉植入术后三维扫描的配对患者（2 组）。所有患者均进行了仪器化脊柱节段的术后计算机断层扫描。在矢状面和轴位重建平面上进行了以下测量，并进行了比较：螺钉位置分类、椎弓根最大轴向直径、螺钉皮质穿孔。此外，在 1 组中测量了受伤节段上下终板之间的距离、后椎体壁的高度、后骨壁的脱位以及椎管的最小直径。
术中椎弓根螺钉位置评分和椎弓根宽度测量在两组中均与计算机断层扫描结果有显著一致性。只有在 24 次三维扫描中才能进行“后骨壁脱位”和“椎管直径”的测量，与 CT 数据相比有显著差异。与仅组装固定器的 1 组相比，2 组的图像质量评分明显更好。
在目前的增强器一代中，进行术中三维成像的理想时间是在椎弓根螺钉插入后直接进行。只有通过术后计算机断层扫描才能可靠地确定椎管直径、后骨壁碎片和确切的骨折形态。
