Comparison of the accuracy of lower cervical anterior transpedicular screws between three-dimensional printing assembly navigation template and free hand placement / 中国组织工程研究

ABSTRACT

BACKGROUND:Lower cervical anterior transpedicular screw technology combines the advantages of the anterior and posterior surgery;therefore, the pressure releasing and reconstruction problems can be solved via one time anterior surgery, whereas, the difficulty and risk of the operation are increased. However, the three-dimensional (3D) printing assembly navigation template improves the safety and accuracy of screw placement. OBJECTIVE:To explore the feasibility and accuracy of 3D printing assembly navigation template in lower cervical anterior transpedicular screws and compare it with free hand pedicle screw placement. METHODS:Lower cervical spine specimens of six adult (2 males, 4 females, average age 58.5 years old ranged from 53 to 64 years) corpses were equal y and randomly divided into two groups. Group A underwent free hand pedicle screw placement. Groups B (lower cervical anterior transpedicular screws assisted by personalized 3D printing combined navigation template)Three cadaveric lower cervical spines were examined using CT and data in DICOM format were recorded. After data were processed using software Mimics for 3D model reconstruction, computer-assisted design of optimum trajactory for lower cervical (C3-C7) anterior transpedicular screws placement was worked out and made into a dril template, where the surface was created as the inverse of anterior surface of cervical vertebra. The dril template was materialized in a 3D printing and used to place the screws. Subsequently, CT scan was performed to evaluate the screw orientation and acceptability. RESULTS AND CONCLUSION:(1) Thirty screws were inserted in Group A. The pedicle perforation was classified by CT, Grade 122 screws, Grade 26 screws, Grade 32 screws;insertion rate was acceptable (Grades 1-2)28 (93%). Thirty screws were inserted in Group B. The pedicle perforation was classified by CT, Grade 125 screws, Grade 24 screws, Grade 31 screw;insertion rate was acceptable (Grades 1-2)29 (97%). There were no statistical y significant differences in the rate of acceptable insertion and orientation between two groups (P>0.05). (2) These results suggested that 3D printing combined navigation template consisted with dril hole cap and screw hole, with functions of double direction. Compared with the traditional method, personalized 3D printing combined navigation template can be used simply.