PDF(Pubmed)
Abstract：
BACKGROUND: Lateral mass screw fixation is the standard for posterior cervical fusion between C3 and C6. Traditional trajectories stabilize but carry risks, including nerve root and vertebral artery injuries. Minimally invasive spine surgery (MISS) is gaining popularity, but trajectories present anatomical challenges.
OBJECTIVE: This study proposes a novel pars interarticularis screw trajectory to address these issues and enhance in-line instrumentation with cervical pedicle screws.
METHODS: A retrospective analysis of reformatted cervical CT scans included 10 patients. Measurements of the pars interarticularis morphology were performed on 80 segments (C3-C6). Two pars interarticularis screw trajectories were evaluated: Trajectory A (upper outer quadrant entry, horizontal trajectory) and Trajectory B (lower outer quadrant entry, cranially pointed trajectory). These were compared to standard lateral mass and cervical pedicle screw trajectories, assessing screw lengths, angles, and potential risks to the spinal canal and transverse foramen.
RESULTS: Trajectory B showed significantly longer pars lengths (15.69 ± 0.65 mm) compared to Trajectory A (12.51 ± 0.24 mm; p < 0.01). Lateral mass screw lengths were comparable to pars interarticularis screw lengths using Trajectory B. Both trajectories provided safe angular ranges, minimizing the risk to delicate structures.
CONCLUSIONS: and Conclusion. Pars interarticularis screws offer a viable alternative to lateral mass screws for posterior cervical fusion, especially in MISS contexts. Trajectory B, in particular, presents a feasible and safe alternative, reducing the risk of vertebral artery and spinal cord injury. Preoperative assessment and intraoperative technologies are essential for successful implementation. Biomechanical validation is needed before clinical application.
OBJECTIVE: This study proposes a novel pars interarticularis screw trajectory to address these issues and enhance in-line instrumentation with cervical pedicle screws.
METHODS: A retrospective analysis of reformatted cervical CT scans included 10 patients. Measurements of the pars interarticularis morphology were performed on 80 segments (C3-C6). Two pars interarticularis screw trajectories were evaluated: Trajectory A (upper outer quadrant entry, horizontal trajectory) and Trajectory B (lower outer quadrant entry, cranially pointed trajectory). These were compared to standard lateral mass and cervical pedicle screw trajectories, assessing screw lengths, angles, and potential risks to the spinal canal and transverse foramen.
RESULTS: Trajectory B showed significantly longer pars lengths (15.69 ± 0.65 mm) compared to Trajectory A (12.51 ± 0.24 mm; p < 0.01). Lateral mass screw lengths were comparable to pars interarticularis screw lengths using Trajectory B. Both trajectories provided safe angular ranges, minimizing the risk to delicate structures.
CONCLUSIONS: and Conclusion. Pars interarticularis screws offer a viable alternative to lateral mass screws for posterior cervical fusion, especially in MISS contexts. Trajectory B, in particular, presents a feasible and safe alternative, reducing the risk of vertebral artery and spinal cord injury. Preoperative assessment and intraoperative technologies are essential for successful implementation. Biomechanical validation is needed before clinical application.
摘要：
背景：侧块螺钉固定是C3和C6颈椎后路融合的标准。传统轨迹稳定但有风险，包括神经根和椎动脉损伤.微创脊柱手术（MISS）越来越受欢迎，但是轨迹带来了解剖学上的挑战。
目的：这项研究提出了一种新颖的关节间螺钉轨迹来解决这些问题并增强颈椎椎弓根螺钉的在线器械。
方法：回顾性分析重新格式化的宫颈CT扫描包括10例患者。在80个节段（C3-C6）上进行了关节间壁形态的测量。评估了两个关节间螺钉轨迹：轨迹A（上部外象限进入，水平轨迹)和轨迹B(下部外象限入口，头颅指向的轨迹)。将这些与标准侧块和颈椎椎弓根螺钉轨迹进行比较，评估螺钉长度，angles,以及椎管和横孔的潜在风险。
结果：与轨迹A（12.51±0.24mm；p<0.01）相比，轨迹B显示出明显更长的pars长度（15.69±0.65mm）。横向质量螺钉长度与使用轨迹B的关节间螺钉长度相当。两个轨迹都提供了安全的角度范围。将精致结构的风险降至最低。
结论：和结论。关节间螺钉为颈椎后路融合侧块螺钉提供了可行的替代方案，尤其是在MISS环境中。轨迹B,特别是,提出了一个可行和安全的替代方案，降低椎动脉和脊髓损伤的风险。术前评估和术中技术对于成功实施至关重要。在临床应用之前需要生物力学验证。
目的：这项研究提出了一种新颖的关节间螺钉轨迹来解决这些问题并增强颈椎椎弓根螺钉的在线器械。
方法：回顾性分析重新格式化的宫颈CT扫描包括10例患者。在80个节段（C3-C6）上进行了关节间壁形态的测量。评估了两个关节间螺钉轨迹：轨迹A（上部外象限进入，水平轨迹)和轨迹B(下部外象限入口，头颅指向的轨迹)。将这些与标准侧块和颈椎椎弓根螺钉轨迹进行比较，评估螺钉长度，angles,以及椎管和横孔的潜在风险。
结果：与轨迹A（12.51±0.24mm；p<0.01）相比，轨迹B显示出明显更长的pars长度（15.69±0.65mm）。横向质量螺钉长度与使用轨迹B的关节间螺钉长度相当。两个轨迹都提供了安全的角度范围。将精致结构的风险降至最低。
结论：和结论。关节间螺钉为颈椎后路融合侧块螺钉提供了可行的替代方案，尤其是在MISS环境中。轨迹B,特别是,提出了一个可行和安全的替代方案，降低椎动脉和脊髓损伤的风险。术前评估和术中技术对于成功实施至关重要。在临床应用之前需要生物力学验证。
