Abstract：Objective To investigate the primary clinical application of digital drill template-assisted screw placement for atlantoaxial instability.Methods CT scan was performed on 28 patients with reducible atlantoaxial instability treated between February 2010 and December 2013 and DICOM format data were obtained to generate a three-dimensional reconstruction model using Mimics software.Optimal trajactory of posterior atlantoaxial screw fixation was designed with a base plate which was an individual complementary template for the posterior atlantoaxial corresponding anatomical surface,and then the drill guide template was materialized in rapid prototyping machine and used intraoperatively to assist screw instrumentation after high temperature sterilization.Position of the screws was determined through cervical radiography and CT scan after operation.Results All patients treated by screw fixation were assisted with drill template.Three patients had atlas pedicle and axial pedicle + lamina screw fixation and the rest underwent posterior atlantoaxial pedicle screw fixation.Fifty-six C1 pedicle screws,53 C2 pedicle screws,and 3 C2 lamina screws were accurately inserted without destruction of the cortical bone and the technique-related complications.Conclusions Digital drill template technique is flexible and accurate enough to assist different combined screw fixation to treat atlantoaxial instability.The accuracy of the screw inserting is increasingly affected by the human factors in clinics,avoiding of which can improve the precision of screw inserting and avoid the neurovascular injury.
. Clinical application of digital drill template-assisted screw placement for atlantoaxial instability[J]. CHINESE JOURNAL OF TRAUMA, 2014, 30(8): 768-773.
