Accuracy of screw placement in child’s thoracic pedicle assisted by digital navigation template / 中国组织工程研究

ABSTRACT

BACKGROUND:Many scholars at home and abroad have already attempted to apply the technique of the internal fixation pedicle screw placement to cure children’s spinal injuries in recent years, because the children’s thoracic pedicle is more smal , anatomical structure variation is big and adjacent relationship is complicated, so the application of adult’s pedicle screw technology simply to children who was in a continuous growth and development can increase operation risk greatly. Above this, improving the accuracy of nailing and reducing error rate become keys for further development of cervical pedicle fixation. OBJECTIVE:To provide an individualized and accurate positioning method for screw placement in thoracic pedicle of children by computer aided design and rapid prototyping technology. METHODS:After computed tomography scan of four cases of child specimens, the original data were made for three-dimensional reconstruction by the software, then the specimens were randomly divided into two groupsone group used the traditional pedicle internal fixation method, and the other group, first created the individual navigation template using the principle of reverse engineering and rapid prototyping technology. The lumbar pedicle screws were put into the samples by the individual navigation template. The position of the pedicle screws was evaluated according to the computer tomography scan. RESULTS AND CONCLUSION:The accurate rate of screw placement of the traditional pedicle internal fixation method was 58%;and the accurate rate of screw placement of the individual digital navigation template method was 81%. The success rate was better than the traditional surgery group. Furthermore, chi square test showed that there was a significant difference between two groups (P<0.05). These findings suggested that there has a high accuracy of the screw placement in thoracic pedicle of children assisted by the individual navigation template, ful y reflects the principle of individualization of screw placement, and provides a new feasible method for accurate screw placement in thoracic pedicle of children.