Application Of Mimics And Rapid Prototyping In Atlantoaxial Pedicle Placement

Objective:To develop and validate a novel method of atlantoaxial pedicle screw placement.Methods:CT scanning of 20 atlantoaxial specimens was performed for the aim of collecting DICOM data,and 20 three dimensional (3D) images were reconstructed by using Mimics, then the data of pedicles of 1-16 3D images were measured by measurement tools of Mimics. The data of pedicles of 1-16 atlantoaxial physical models manufactured by using rapid prototyping were measured,and the data of pedicles of 1-16 atlantoaxial specimens were measured after the soft tissue was removed from the specimens. The accuracy of 3D image and physical model was assessed by analyzing the data of pedicles. The fixation of 17-20 atlantoaxial specimens was proceeded according to the direct guidance of physical models and the optimal pedicle channel designed in Mimics previously,and the accuracy of fixation was assessed by CT scanning.Results:There was no significant difference in the data of pedicles between atlantoaxial specimens and 3D images(P>0.01); there was also no significant difference in the data of pedicles between atlantoaxial specimens and physical models(P>0.01). The 3D images and physical models can accurately reflect the anatomical configuration of atlantoaxial specimens.16 pedicle screws were inserted in 4 atlantoaxial specimens,only one breached the pedicle cortical of axis.Conclusions:The atlantoaxial pedicle screw placement can be safer whit the help of Mimics and physical models made by rapid prototyping technology.