From the Department of Orthopedics, Changzheng Hospital, The Second Military Medical University, Shanghai, People's Republic of China.
From the Department of Orthopedics, Changzheng Hospital, The Second Military Medical University, Shanghai, People's Republic of China.
Clin Neurol Neurosurg. 2021 Jan;200:106403. doi: 10.1016/j.clineuro.2020.106403. Epub 2020 Dec 4.
Although the C2 pedicle screw (C2PS) is currently the most biomechanically robust option for C2 fixation, the high-riding vertebral artery (HRVA) precludes safe C2PS placement. However, unintentional partial C2 pedicle perforation and vertebral foramen violation due to C2PS placement without neurovascular complications occurred frequently in clinic. Therefore, we have attempted to apply C2 partial transpedicular screw (C2PTS) in patients with HRVA with satisfactory preliminary outcomes. The aim of the present study is to introduce the C2PTS technique and report the preliminary radiological and clinical outcomes of application of C2PTS.
The data of 15 patients with atlantoaxial dislocation underwent atlantoaxial arthrodesis with posterior screw-rod construct were retrospectively reviewed. All patients had unilateral or bilateral HRVA that precluded safe C2PS placement and C2PTS was used as an alternative. In this technique, a Penfield dissector was used to properly mobilize the HRVA inferiorly to preclude vertebral artery injury and pave the way for C2PTS placement. The C2PTS travelled under the superior border of the isthmus and toward the ipsilateral atlantoaxial articulation. The implant position and atlantoaxial reduction were evaluated using computed tomography (CT) scans and vertebral artery (VA) was assessed using CT angiography postoperatively.
Satisfactory C2PTS placement and atlantoaxial reduction were achieved in all patients. Postoperatively, no vertebral artery injury and implant failure were observed, and bone fusion was achieved in all the patients. Additionally, there were no VA occlusion or stenosis due to screws demonstrated on VA CT angiography.
C2PTS can achieve three-column fixation of axis and is an efficient alternative to C2PS which is prohibited due to HRVA; also, gently mobilizing the HRVA inferiorly is mandatory to prevent vertebral artery injury during C2PTS placement.
尽管 C2 椎弓根螺钉（C2PS）目前是 C2 固定最具生物力学稳定性的选择，但高位椎动脉（HRVA）妨碍了安全的 C2PS 放置。然而，在临床实践中，由于 C2PS 放置而导致的无意的 C2 椎弓根部分穿透和椎弓根孔侵犯，且无神经血管并发症，这种情况经常发生。因此，我们试图在 HRVA 患者中应用 C2 部分经椎弓根螺钉（C2PTS），并取得了满意的初步结果。本研究旨在介绍 C2PTS 技术，并报告应用 C2PTS 的初步放射学和临床结果。
回顾性分析了 15 例接受后路螺钉-棒固定寰枢关节融合术的寰枢关节脱位患者的数据。所有患者均有单侧或双侧 HRVA，妨碍了安全的 C2PS 放置，因此使用 C2PTS 作为替代。在该技术中，使用 Penfield 剥离器适当向下移动 HRVA，以防止椎动脉损伤，并为 C2PTS 放置铺平道路。C2PTS 沿峡部的上缘向同侧寰枢关节走行。术后使用计算机断层扫描（CT）评估 C2PTS 植入物的位置和寰枢关节复位情况，使用 CT 血管造影评估椎动脉（VA）情况。
所有患者均获得满意的 C2PTS 放置和寰枢关节复位。术后未见椎动脉损伤和植入物失败，所有患者均获得骨融合。此外，VA CT 血管造影未见因螺钉导致的 VA 闭塞或狭窄。
C2PTS 可实现对枢椎的三柱固定，是由于 HRVA 而禁止使用 C2PS 的有效替代方法；此外，在放置 C2PTS 时，必须向下轻轻移动 HRVA，以防止椎动脉损伤。
