Department of Neurosurgery, Health Sciences University Turkey, Bagcilar Training and Research Hospital, Istanbul, Turkey,
Department of Neurosurgery, Health Sciences University Turkey, Bagcilar Training and Research Hospital, Istanbul, Turkey.
Pediatr Neurosurg. 2021;56(1):10-16. doi: 10.1159/000513371. Epub 2021 Feb 4.
The laminar screw method was popularized during recent years. Since no data exist in the literature on its suitability for subaxial levels in the pediatric population, a radiologic anatomical study was planned to evaluate the suitability of the laminae for laminar screws in children.
The laminar thicknesses from C3 to C7 were measured in axial sections in 120 pediatric patients using computed tomography. The patients were divided into 3 age-groups: ages 4-6, 7-9, and 10-12. Each age-group consisted of 20 boys and 20 girls. The suitability of the laminae was evaluated for 3.5-mm-thick commercially available screws and also for the 3-mm screws that could be produced in the future. If the height of the base of the spinous process is ≥ 9 mm, the segment was accepted as suitable for the bilateral screw, and ≥5 mm is for the unilateral screw. Additionally, laminar thickness and length were measured for possible short screws longer than 15 mm in the laminae that were distally thin but proximally thick.
The C4 and C5 levels had the thinnest (2.77 ± 0.6 mm and 2.81 ± 0.6 mm, respectively) and C7 had the thickest laminae (4.66 ± 0.6 mm) in all age-groups. No significant differences were found between boys and girls and right and left laminae. According to the age-groups, an increase in laminar thickness was possible by growing, but only C7 laminae thickness was statistically different between 10-12 and 4-6 age-groups (p < 0.001). The last rate of the suitability was 9.1% for the 3.5-mm-thick screws and 13.75% for the 3-mm-thick screws after deletion of the bilateral insertion due to the short base of the spinous process and adding the possible short screws in the distally thin but proximally thick laminae. The rates increased with age, but the only statistically significant difference was found between 4-6- and 10-12-year-old age-groups (p < 0.001).
Laminar screws may be suitable for some levels of C7, C6, and C3 even in the young pediatric population. The use of thinner screws (3 mm) may increase the suitability rate. Therefore, laminar screw choice may be considered as a salvage method in pediatric patients, and all laminae may be evaluated individually for suitability. This study did not evaluate the safety and efficacy of the method in children, and these issues must be studied further.
层板螺钉法近年来得到了普及。由于文献中尚无关于其在儿童下颈椎段适用性的资料，因此我们进行了一项放射解剖学研究，以评估儿童使用层板螺钉时，层板的适用性。
我们在 120 例儿科患者的 CT 轴位片上测量了 C3 至 C7 的层板厚度。将患者分为 3 个年龄组：4-6 岁、7-9 岁和 10-12 岁。每个年龄组均有 20 名男孩和 20 名女孩。我们评估了 3.5 毫米厚的商用螺钉以及未来可生产的 3 毫米厚螺钉在各层板的适用性。如果棘突基底部的高度≥9 毫米，则认为该节段双侧螺钉适用，单侧螺钉适用高度≥5 毫米。此外，我们还测量了可能在远端较薄而近端较厚的层板中使用长于 15 毫米的短螺钉时的层板厚度和长度。
在所有年龄组中，C4 和 C5 水平的层板最薄（分别为 2.77 ± 0.6 毫米和 2.81 ± 0.6 毫米），而 C7 水平的层板最厚（4.66 ± 0.6 毫米）。男孩和女孩之间以及左右层板之间没有明显差异。按年龄组划分，层板厚度随着生长而增加，但只有 C7 层板厚度在 10-12 岁和 4-6 岁年龄组之间存在统计学差异（p < 0.001）。剔除因棘突基部短而双侧插入的螺钉后，3.5 毫米厚螺钉的最后适合率为 9.1%，3 毫米厚螺钉的最后适合率为 13.75%，并增加了可能在远端较薄而近端较厚的层板中使用的短螺钉。随着年龄的增长，适合率有所增加，但只有 4-6 岁和 10-12 岁年龄组之间存在统计学差异（p < 0.001）。
即使在年幼的儿科患者中，层板螺钉也可能适用于 C7、C6 和 C3 的某些水平。使用更薄的螺钉（3 毫米）可能会提高适合率。因此，在儿科患者中，可考虑选择层板螺钉作为挽救方法，并且可以单独评估所有层板的适用性。本研究并未评估该方法在儿童中的安全性和有效性，这些问题还需进一步研究。
