The Effect Of Pedicle Screw On The Growth Of 1-6 Years Old Children Vertebra

Objective :The purpose of the present study is to examine the influence of the pedicle screw insertion through the neurocentral cartilage(NCC)on the growth of the vertebra in animal experiment.Methods: 22 Myelography of entire spinal canal of the children (about 1 to 6 years old ) who have experienced Pedicle Screws Operation were randomly assigned into 2 groups: group A(l to 3 years old), group B(4 to 6 years old). The stuided vertbra is assigned as the vertebral body which has both pedicles screw insertion or the mean of adjacent vertebral bodies which have both pedicles screw insertion .And the control vertbra is assigned as the mean of adjacent vertebral bodies which have not screw. The mophologic parameters of spine are assigned as the head-end portaitlength of the vertbra, the caudal-end portaitlengh of the vertbra, the front-end height of the vertbra, the back-end height of the vertbra, the distance between the anterior border of the vertebral body and the posterior border of the processus spinosus, the lateral area of the vertebra body. The computer image analysis software can measure the morphologic parameters of studied vertebras and their control vertebras on the first week after operation and 1 years after operation. By paired t-tests of stuidied vertebras and their control vertebras, we can evaluate the effect the pedicle screws insertion on the morphological development.Results: The followed data after 3 to 4 years after operation illustrates: In group A , there were no significantly between the portaitlength of the studied vertbras and their control vertebras(P>0.05). In group B , there were no significantly between the portaitlength of the studied vertbras and their control vertebras(P>0.05) . And on the first week or 1 year after operation of both group A and B , there were no significantly between the portaitlength of the studied vertbras and their control vertebras(P>0.05) . Also , in the both groups ,there were no significantly between the head-end portaitlength , the caudal-end portaitlengh , the front-end height the back-end height and the lateral area of the vertbra of the studied vertbras and their control vertebras(P>0.05).Conclusion: These findings suggest that:1. Pedicle screw placement has no significant effect on the portaitlength of the children's vertbras and the morphological development in short term (1 year).2. Pedicle screw placement has no significant effect on the portaitlength of the children's(1 to 3 years old) vertbras and the morphological development in long term ( 3 to 4 years).3. Pedicle screw placement has no significant effect on the portaitlength of the children's(1 to 3 years old) vertbras and the morphological development in long term (4 to 6 years).