幼猪胸腰椎椎弓根参数的CT测量对置钉的指导意义

目的]采用CT扫描测量约克夏幼猪的胸腰椎椎弓根螺钉置入的相关参数,提供动物实验的解剖学参考数据。方法]10只6周龄的雌性约克夏幼猪进行CT平扫三维重建后测量T1～L5的椎体高度、椎体横径、椎体纵径、椎管横径、椎弓根骨性通道全长、椎弓根宽度等参数,按照测量数据置入椎弓根螺钉,术后再次行CT扫描检查,评估螺钉置入准确性。结果]根据CT影像学测量结果,椎弓根宽度平均为5.3～7.4 mm,椎弓根骨性通道全长平均为18.8～22.6 mm,椎弓根水平面置入角度平均为32.1°～44.4°之间。根据测量数据,选取直径为4.5 mm,长度为25 mm的椎弓根螺钉,并在幼猪脊柱成功置入,固定效果可靠。结论]尽管幼猪的脊椎较小,通过术前CT测量的指导,可以有效地指导椎弓根螺钉的置入。

CT-based quantification of the thoracic and lumbar pedicle morphology of immature porcine and the significance for pedicle screw implantation

Objective] To measure the morphologic parameters of Yorkshire pig’ s thoracic and lumbar vertebrae with CT scan and provide anatomic reference data for pedicle screw placement for animal experiment.Methods]Ten Yorkshire pigs(6-week aged,female) were included.All the pigs underwent CT scan from T1 to L5.The following parameters were measured: the height and transverse diameter of vertebral body(HVB,TDVB),anteroposterior distance of vertebral body(APDB),transverse diameter of vertebral canal(TDVC),the total length and width of the pedicle(TL,PedW).Pedicle screws were inserted according to the parameters and postoperative CT scan was performed to evaluate the accuracy of the pedicle screws.Results]The CT scans revealed that the width of the pedicle and the total length of the pedicle path were 5.3~7.4 mm and 18.8~22.6 mm,respectively.The transverse screw angle was 32.1~44.4°.Based on the above parameters,pedicle screws with 4.5 mm in diameter and 25 mm in length were inserted successfully.Conclusion]Despite the small pedicle of the immature porcine,it is possible to insert pedicle screws effectively with the guidance of preoperative CT scan.