Department of Radiology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan.
Department of Medical Imaging and Radiological Technology, Yuanpei University of Medical Technology, Hsinchu, Taiwan.
PLoS One. 2023 Apr 10;18(4):e0282737. doi: 10.1371/journal.pone.0282737. eCollection 2023.
Intraoperative navigation systems have been widely applied in spinal fusion surgery to improve the implantation accuracy of spinal screws using orthogonal tomographic and surface-rendering imaging. However, these images contain limited anatomical information and no information on bone volume contact by the implanted screw, which has been proven to affect the stability of implanted screws. This study proposed a novel drilled surface imaging technique that displays anatomical integration properties to calculate the contact bone volume (CBV) of the screws implanted along an implantation trajectory. A cylinder was used to represent the area traversed by the screws, which was manually rotated and translated to a predetermined implantation trajectory according to a vertebra model obtained using computed tomography (CT) image volumes. The drilled surface image was reconstructed by interpolating the CT numbers at the predefined sampling points on the cylinder surface. The anatomical integration property and CBV of the screw implanted along the transpedicular trajectory (TT) and cortical bone trajectory (CBT) were evaluated and compared. The drilled surface image fully revealed the contact anatomical structure of the screw under the trajectories, improving the understanding of the anatomical integration of the screw and surrounding tissues. On average, the CBV of the CBT was 30% greater than that of the TT. The proposed drilled surface image may be applied in preoperative planning and integrated into intraoperative navigation systems to evaluate the anatomical integration and degree of bone contact of the screw implanted along a trajectory.
术中导航系统已广泛应用于脊柱融合手术中，以提高使用正交断层和表面渲染成像的脊柱螺钉植入的准确性。然而，这些图像包含有限的解剖学信息，并且没有植入螺钉与骨接触的体积信息，事实证明这会影响植入螺钉的稳定性。本研究提出了一种新的钻孔表面成像技术，该技术显示解剖整合特性，以计算沿植入轨迹植入的螺钉的接触骨体积（CBV）。使用圆柱体来代表螺钉所经过的区域，根据使用 CT 图像体积获得的椎体模型，手动旋转和平移圆柱体以到达预定的植入轨迹。通过在圆柱体表面上的预定义采样点插值 CT 数来重建钻孔表面图像。评估和比较了沿经皮轨迹（TT）和皮质骨轨迹（CBT）植入的螺钉的钻孔表面图像的解剖整合特性和 CBV。钻孔表面图像充分显示了轨迹下螺钉的接触解剖结构，提高了对螺钉和周围组织解剖整合的理解。平均而言，CBT 的 CBV 比 TT 高 30%。所提出的钻孔表面图像可应用于术前规划，并集成到术中导航系统中，以评估沿轨迹植入的螺钉的解剖整合和骨接触程度。
