Fu Sheng-Yu, Liu Huan, Wang Zhao-Rui, Wang Bang, Li Xing-Bin, Huang Ai-Bing
Department of Orthopedics, Taizhou People's Hospital Affiliated to Nanjing Medical University, Taizhou, 225300, Jiangsu, China.
Postgraduate School, Dalian Medical University, Dalian, 116000, Liaoning, China.
Eur Spine J. 2022 Dec;31(12):3426-3432. doi: 10.1007/s00586-022-07374-w. Epub 2022 Sep 4.
To identify the ideal entry point for pediatric C2 pedicle screw and to obtain parameters of it for the indication of pediatric atlantoaxial fusion arthrodesis.
The pediatric cervical CT images were reconstructed into the 3D digital models and the C2 vertebrae were separated. The location of ideal entry point and screw placement related linear and angular parameters were assessed on the 3D digital models.
A total of 214 pedicles from 107 C2 digital models were analyzed. The average entry point for C2 was 3.80 ± 2.78 mm medial to the lateral notch (LN) and 2.57 ± 1.70 mm superior to the LN. The average pedicle diameter (PD) was 6.02 ± 1.31 mm, and the average pedicle screw length (PSL) was 25.63 ± 3.46 mm. Statistical differences were found between different sex for PD and PSL (P < 0.05). As patient age increases, using the most lateral and inferior edge of the lateral mass as a reference marker, the entry point tends to move medial and cephalad, when using the LN as a reference marker, the entry point tends to move medial and slightly caudad. Univariate linear regression analysis suggested that these linear parameters were associated with age (P < 0.01).
In this study, we found that the measurement results of C2 pedicle screw varied based on sex, laterality, and ages for children younger than 18 years. The entry point of the screws facilitating ideal trajectory tends to change in a linear way as a function of age. This information helps the surgeon to establish the specific anatomy related to C2 pedicle screw placement to facilitate fixation in the pediatric patients.
确定儿童C2椎弓根螺钉的理想进针点，并获取其参数以用于儿童寰枢椎融合固定术的指征。
将儿童颈椎CT图像重建为三维数字模型并分离出C2椎体。在三维数字模型上评估理想进针点的位置以及与螺钉置入相关的线性和角度参数。
共分析了107个C2数字模型中的214个椎弓根。C2的平均进针点位于外侧切迹（LN）内侧3.80±2.78mm、LN上方2.57±1.70mm处。平均椎弓根直径（PD）为6.02±1.31mm，平均椎弓根螺钉长度（PSL）为25.63±3.46mm。PD和PSL在不同性别间存在统计学差异（P<0.05）。随着患者年龄增加，以侧块最外侧和最下缘为参考标志时，进针点趋于向内侧和头侧移动；以LN为参考标志时，进针点趋于向内侧和稍尾侧移动。单因素线性回归分析表明这些线性参数与年龄相关（P<0.01）。
在本研究中，我们发现18岁以下儿童C2椎弓根螺钉的测量结果因性别、左右侧别和年龄而异。有利于理想轨迹的螺钉进针点倾向于随年龄呈线性变化。这些信息有助于外科医生确定与C2椎弓根螺钉置入相关的具体解剖结构，以利于儿童患者的固定。
