3~10岁儿童颈椎椎弓根CT影像学参数测量研究

Measurement of CT Imaging Parameters of Cervical Pedicles in Children Aged 3 to 10 Years

摘要: 背景：颈椎椎弓根螺钉(cervical pedicle screw, CPS)技术因其优异的生物力学稳定性，已广泛应用于颈椎管狭窄、颈椎侧后凸畸形等各种颈椎疾患中。然而，儿童颈椎因骨性结构发育未成熟、解剖变异大、毗邻椎动脉及脊髓等重要结构，置钉难度显著增加，且目前缺乏系统的儿童颈椎椎弓根解剖学数据支持。本研究旨在通过高分辨率CT影像精确测量3~10岁儿童颈椎椎弓根的各项解剖学参数，分析年龄、节段对解剖形态的影响规律，为儿童颈椎椎弓根螺钉的尺寸选择、置钉点定位及进钉角度规划提供解剖学依据，以降低置钉相关并发症风险。方法：回顾性分析2018年1月至2024年9月于我院行颈椎CT检查的196例儿童患者的影像学资料，其中男104例，女92例，平均年龄(6.2 ± 2.2)岁。根据年龄分为<5岁组(61例)和5~10岁组(135例)。所有患者均行颈椎螺旋CT薄层扫描(层厚 ≤ 1 mm)及三维重建，利用Light Speed工作站测量C1~C7各节段椎弓根宽度(pedicle width, PW)、椎弓根轴线长(pedicle axis length, PAL)、椎弓根外倾角(transverse pedicle angle, tPA)及椎弓根头倾角(sagittal pedicle angle, sPA)。采用独立样本t检验比较两组间差异，P < 0.05为差异有统计学意义。结果：儿童颈椎椎弓根参数呈现显著的年龄和节段相关性。(1) 椎弓根宽度：<5岁组各节段PW均显著小于5~10岁组(P < 0.05)，其中C1最宽(<5岁组：7.8 ± 0.4 mm；5~10岁组：9.4 ± 0.7 mm)，C3最窄(<5岁组：4.7 ± 0.4 mm；5~10岁组：5.6 ± 0.6 mm)，C3~C7呈逐级增宽趋势。(2) 椎弓根轴线长：PAL随节段递增(C1→C7)，且5~10岁组显著大于<5岁组(P < 0.05)。(3) 角度参数：tPA和sPA个体化变异较大(标准差较大)，但C2节段sPA显著大于其他节段，且C1~C4 sPA为正值(头倾)，C5~C7转为负值(尾倾)，与颈椎生理曲度相符。值得注意的是，<5岁组C3节段PW 60%以上测量值 < 5 mm，提示该年龄段C3置钉存在较高皮质穿破风险。结论：3~10岁儿童颈椎椎弓根解剖参数随年龄增长和节段下移呈现规律性变化，但个体差异显著，尤其是C3节段狭窄、C2节段头倾角大等特征对置钉技术提出特殊要求。本研究建立的解剖学参数数据库可为儿童颈椎椎弓根螺钉的个体化选择(螺钉直径、长度、进钉点及角度)提供精准参考，对降低椎动脉损伤、神经根损伤及内固定失效等并发症具有重要临床指导意义。建议5岁以下患儿行CPS固定前必须进行精细化CT评估，必要时采用计算机辅助导航技术以确保置钉安全。

Abstract: Objective: Cervical pedicle screw (CPS) fixation, renowned for its excellent biomechanical stability, has been widely employed in various cervical pathologies including cervical spinal stenosis and cervical kyphoscoliotic deformities. However, the application of CPS in pediatric patients remains technically demanding due to immature osseous development, substantial anatomical variability, and the close proximity to critical neurovascular structures such as the vertebral artery and spinal cord. Furthermore, systematic anatomical data regarding pediatric cervical pedicles remain scarce. This study aims to precisely measure the anatomical parameters of cervical pedicles in children aged 3~10 years using high-resolution CT imaging, and to analyze the influence of age and vertebral level on morphological characteristics, thereby providing anatomical evidence for screw dimension selection, entry point localization, and trajectory planning in pediatric cervical pedicle screw fixation, ultimately reducing the risk of screw-related complications. Methods: We retrospectively analyzed cervical CT images of 196 children (104 males, 92 females; mean age 6.2 ± 2.2 years) who underwent thin-slice CT scanning (slice thickness ≤ 1 mm) with three-dimensional reconstruction at our center from January 2018 to September 2024. Patients were divided into two groups: <5 years (n = 61) and 5~10 years (n = 135). Using the Light Speed workstation, we measured pedicle width (PW), pedicle axis length (PAL), transverse pedicle angle (tPA), and sagittal pedicle angle (sPA) at C1~C7 levels. Independent sample t-tests were used for between-group comparisons, with P < 0.05 considered statistically significant. Results: Pediatric cervical pedicle parameters showed significant age- and level-dependent patterns. (1) Pedicle width: The <5-year group demonstrated significantly smaller PW values than the 5~10-year group at all levels (P < 0.05). C1 exhibited the largest PW (<5 y: 7.8 ± 0.4 mm; 5~10 y: 9.4 ± 0.7 mm), while C3 was the narrowest (<5 y: 4.7 ± 0.4 mm; 5~10 y: 5.6 ± 0.6 mm), with gradual widening from C3 to C7. (2) Pedicle axis length: PAL increased progressively from C1 to C7 in both groups, with significantly greater values in the 5~10-year group (P < 0.05). (3) Angular parameters: Both tPA and sPA showed considerable interindividual variability. Notably, C2 demonstrated significantly greater sPA compared to other levels. Additionally, sPA values were positive at C1~C4 (cephalad inclination) but negative at C5~C7 (caudad inclination), consistent with cervical physiological curvature. Importantly, over 60% of C3 measurements in the <5-year group were <5 mm, indicating high risk for cortical perforation during screw placement. Conclusions: Anatomical parameters of cervical pedicles in children aged 3~10 years demonstrate regular patterns with age and vertebral level, though individual variation remains substantial. The narrow C3 pedicle and large C2 sagittal angle pose specific technical challenges for screw insertion. The established anatomical database provides precise guidance for individualized CPS selection (screw diameter, length, entry point, and trajectory) and offers important clinical implications for reducing complications such as vertebral artery injury, nerve root damage, and fixation failure. We recommend meticulous preoperative CT evaluation PW for children under 5 years, with consideration of computer-assisted navigation techniques when necessary to ensure screw placement safety.