Abstract: Objective　To investigate the feasibility of axial lamina fixation with 3.5mm 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.

Key words: Children, 　Axial lamina, 　Screw internal fixation, 　Spiral CT