Department of Orthopedic Surgery, Spine Center, Konan Kosei Hospital, Takaya Chou, Konan City, Japan.
J Neurosurg Spine. 2011 Nov;15(5):472-8. doi: 10.3171/2011.6.SPINE10809. Epub 2011 Jul 15.
The aim of this study was to retrospectively evaluate the reliability and accuracy of cervical pedicle screw (CPS) placement using an intraoperative, full-rotation, 3D image (O-arm)-based navigation system and to assess the advantages and disadvantages of the system.
The study involved 21 consecutive patients undergoing posterior stabilization surgery of the cervical spine between April and December 2009. The patients, in whom 108 CPSs had been inserted, underwent screw placement based on intraoperative 3D imaging and navigation using the O-arm system. Cervical pedicle screw positions were classified into 4 grades, according to pedicle-wall perforations, by using postoperative CT.
Of the 108 CPSs, 96 (88.9%) were classified as Grade 0 (no perforation), 9 (8.3%) as Grade 1 (perforations < 2 mm, CPS exposed, and < 50% of screw diameter outside the pedicle), and 3 (2.8%) as Grade 2 (perforations between ≥ 2 and < 4 mm, CPS breached the pedicle wall, and > 50% of screw diameter outside the pedicle). No screw was classified as Grade 3 (perforation > 4 mm, complete perforation). No neurovascular complications occurred because of CPS placement.
The O-arm offers high-resolution 2D or 3D images, facilitates accurate and safe CPS insertion with high-quality navigation, and provides other substantial benefits for cervical spinal instrumentation. Even with current optimized technology, however, CPS perforation cannot be completely prevented, with 8.3% instances of minor violations, which do not cause significant complications, and 2.8% instances of major pedicle violations, which may cause catastrophic complications. Therefore, a combination of intraoperative 3D image-based navigation with other techniques may result in more accurate CPS placement.
本研究旨在回顾性评估术中全旋转三维图像（O 臂）导航系统辅助下颈椎椎弓根螺钉（CPS）置入的可靠性和准确性，并评估该系统的优缺点。
本研究纳入 2009 年 4 月至 12 月期间行颈椎后路稳定手术的 21 例连续患者。在术中 O 臂系统引导下，21 例患者共置入 108 枚 CPS。根据术后 CT，将颈椎椎弓根螺钉位置分为 4 级，根据椎弓根壁穿孔情况进行分类。
108 枚 CPS 中，96 枚（88.9%）归为 0 级（无穿孔），9 枚（8.3%）归为 1 级（穿孔<2mm，CPS 暴露，<50%的螺钉直径超出椎弓根），3 枚（2.8%）归为 2 级（穿孔在 2~4mm 之间，CPS 突破椎弓根壁，>50%的螺钉直径超出椎弓根）。无螺钉归为 3 级（穿孔>4mm，完全穿孔）。由于 CPS 放置，未发生任何血管神经并发症。
O 臂可提供高分辨率的二维或三维图像，有助于实现准确、安全的 CPS 置入，并为颈椎脊柱器械提供其他实质性的益处。然而，即使使用目前优化的技术，仍无法完全避免 CPS 穿孔，轻微违规发生率为 8.3%，不会引起严重并发症，严重违规发生率为 2.8%，可能导致灾难性并发症。因此，术中三维图像导航与其他技术相结合可能会使 CPS 置入更准确。
