1~6岁儿童枢椎经椎板螺钉内固定的可行性研究

Feasibility study of axial laminar screw fixation in children aged 1~6 years

目的探讨1~6岁儿童枢椎经椎板行3.5 mm螺钉内固定的可行性。方法选取1~6岁儿童45例,每两岁一组分为A、B、C 3组,将其颈椎CT原始数据行三维重建后测量椎板上、中、下缘宽度,椎板高和长度,椎板上倾角及内倾角等参数。结果椎板各指标随年龄增长呈上升趋势。限制枢椎板螺钉置钉的主要因素是椎板中缘宽(LWM)和进钉点至椎板外缘距离(ELE),LWM中A组为(4.69±0.45)mm;B组(7.13±1.61)mm;C组(7.72±1.28)mm。ELE中A组为(15.44±6.98)mm,B组(23.67±1.86)mm;C组(27.75±2.39)mm。模拟椎板螺钉置入时,A组入钉点为同侧棘突左、右分支交界处;B组入钉点为螺钉所在椎板对侧的棘突分支中缘;C组入钉点为螺钉所在椎板对侧的棘突分支上缘。结论1~6岁儿童枢椎板均具有置入3.5 mm螺钉的可行性,但不同年龄置钉方式应有所不同。

Objective To investigate the feasibility of axial lamina fixation with 3.5 mm screw in children aged from 1 to 6 years.Methods The original CT data of 45 children aged from 1 to 6 years old were collected into three groups of A,B and C.The age difference of children in each group was within 2 years old.The CT data were 3D-reconstructed to measure the following parameters:the width of upper edge,middle edge,lower edge of the lamina,the height and length of the lamina,the obliquity and the inclination of the lamina.Results With the increasing of age,the indexes of lamina were on the rise.The main factors limiting axial lamina screw placement were lamina midline width(LWM)and distance from the entering point to the lamina outer edge(ELE).The LWM of the A group,the B group and the C group was(4.69±0.45)mm,(7.13±1.61)mm;(7.72±1.28)mm,respectively.The ELE of the A group,the B group and the C group was(15.44±6.98)mm,(23.67±1.86)mm,(27.75±2.39)mm,respectively.In the simulation of lamina screw placement,the entering point of the A group,the B group and the C group was the junction of the right and left branches of the ipsilateral spinous process,the middle edge of spinous process branch on the opposite side of vertebral plate where the screw was located,the upper edge of spinous process branch on the opposite side of the vertebral plate where the screw was located,respectively.Conclusions It is feasible to insert 3.5 mm screw in the axial lamina of children aged 1 to 6 years,but the screw placement method should be different according to the age.