The Imaging Study About The Effect Of Pedicle Screw Rod Fixation At Early Onset Scoliosis On Vertebral Development

Objective:The purpose of this study is to observe the effect of the different diameter pedicle screws fixation at early onset scoliosis on vertebral development through the measurement of imaging data.Methods:The imaging data of 23 patients with early-onset scoliosis (EOS) (< 10 years old) that treated by pedicle screw instrumentation were collected in the second affiliated hospital of kunming medical university orthopaedic from August 2005 to December 2014.Each of the imaging data including the positive side of the all spine X-ray a week after operation and at the age of 5 or 10 years old.All of the patients were divided into two groups that 1-5 years were I group which was further divided into Ⅰ1 group:pedicle screw diameter≤ 4.0 mm and 12 group:pedicle screw diameter> 4.0 mm and 5-10 years were II group that the pedicle screw diameter was more than 4.0 mm according to age and the pedicle screw diameter size.The studied vertebra was bilateral pedicle screw placement and intervertebral bone graft fusion of adjacent vertebral bodies, and not nailing on both sides of the adjacent vertebral body as their own contrasting vertebra. The measurement index of the vertebra was designed asvertebral height,vertebral vector diameter and rod spacing.The various measurement matched two independent samples t test and paired t test by SPSS 18.0 statistical software to compare differences of each measurement about studied vertebra and self-reflection vertebra at different stages and to determine the effect of vertebral development for 1-5 years of age and 5 to 10 years old of early-onset scoliosis patients placed of different diameter size of pedicle screws.Results:There was no statistically significant difference between the vertebral height and vertebral vector diameter of the studied vertebra and contrasting vertebra for the Ⅰ group (Ⅰ1、Ⅰ 2) and Ⅱ group on the first week after operation(P>0.05). There was statistical significance for the difference of the vertebral height and vertebral vector diameter of the studied vertebra and contrasting vertebra for Ⅰ group at the age of five and Ⅱ group at the age of 10(P< 0.05).The difference for the vertebral height and vertebral vector diameter of the study vertebra in Ⅰ and Ⅱ groups had statistical significance on the first week after operation and in the follow-up(five years old and ten years old) (P< 0.05), but the difference of pedicle spacing had no statistical significance. It suggested that the vertebra was still in growth in longitudinal and sagittal plane after fixed by pedicle screws in the follow-up.The difference for each measurement of the study vertebra in Ⅰ and Ⅱ groups had statistical significance (P<0.05).It showed that the effect of pedicle screw rod fixation system was different between 1-5 years old children and 5-10 years old children. The difference for each measurement of vertebra in 12 and Ⅱ group had no statistical significance (P> 0.05).It suggested that the effect of pedicle screw in diameter more than 4.0mm on the growth of the vertebra had no difference between the children of 1-5 years old and 5-10 years old. The difference for each measurement of the study vertebral bodies in Ⅰ1 and Ⅰ 2 groups had no statistical significance (P> 0.05).It showed that there was no significant difference for different types of pedicle screw rod fixation system to the longitudinal and sagittal growth of vertebral bodies in children of the same age.The growth of the study vertebral in longitudinal and sagittal plane was limited respectively 0.22mm/year,0.38 mm/year than control vertebral in Ⅰ group;The growth of the study vertebral in transversal, sagittal plane and longitudinal was limited respectively 0.17mm/year,0.36mm/yearthan control vertebral in Ⅱgroup.The inhibition of pedicle screw fixation for the growth of vertebral longitudinal was smaller in the head and caudal fixed vertebral than in the middle,but it was no significant difference in the sagittal plane.Conclusions:1、 Pedicle screw rod fixation system has a certain degree of restriction for the growth of the vertebra especially in sagittal plane between 1-5 years old children and 5-10 years old children.2、The effect of pedicle screw rod fixation system for the growth of the vertebra is different between the children of 1-5 years old and 5-10 years old.3、The inhibition of pedicle screw rod fixation system for the growth of vertebral longitudinal was smaller in the head and caudal fixed vertebral than in the middle.4、The effect of pedicle screw rod fixation system in different diameters for the growth of the vertebra has no significant difference at the same age.