Study on the accuracy of cervical pedicle screw placement assisted with improved 3D-printed drill guiding template / 中国脊柱脊髓杂志

ABSTRACT

Objectives:To explore the accuracy of pedicle screw placement assisted with improved 3D-print-ed drill guiding template in cervical spine.Methods:The clinical data of 60 patients undergone posterior cervical pedicle screw placement in our hospital between January 2016 and January 2023 were analyzed retro-spectively,including 30 males and 30 females with an average age of 17-84 years(58.7±13.8 years).The pa-tients were divided into guiding template group and free-hand group based on whether the guiding template was used to assist the placement of screws or not.The improved 3D-printed guiding template was used to assist cervical pedicle screw placement in the guiding template group(n=30),and the self-made angular-ruler was used in the free-hand group(n=30).There was no significant difference in age,gender ratio,and preoper-ative diagnosis between the two groups(P＞0.05).Cervical CT scan was performed at one week after surgery,and the accuracy of pedicle screw placement was evaluated according to the Kaneyama standard:Grade 0,the screw was completely in the pedicle;Grade 1,the size of screw penetrating the cortex＜50%of the screw diameter;Grade 2,the size of screw penetrating the cortex≥50%of the screw diameter but not com pletely out;Grade 3,the screw was completely on the outside of the pedicle.The accuracy of pedicle screw placement(ratio of grades 0 and 1)and complications such as vascular and nerve injury,incision infection,cerebrospinal fluid leakage,screw loosening and breakage caused by screw misplacement were recorded.Re-sults:A total of 152 pedicle screws were placed in the guiding template group,including 74 screws of grade 0,68 of grade 1,10 of grade 2 and 0 of grade 3,with an accuracy of screw placement of 93.4%.A total of 136 pedicle screws were placed in free-hand group,including 53 screws of grade 0,61 of grade 1,18 of grade 2 and 4 of grade 3,with an accuracy of screw placement of 83.8%.The accuracy of screw placement in the guiding template group was significantly higher than that in the free-hand group(P＜0.05).There were no related complications such as vascular and nerve injury,incision infection and cerebrospinal fluid leakage caused by misplacement of pedicle screws.The patients were followed up for 5-29 months(14.2±7.7months),and there were no complications such as screw loosening or breakage.Conclusions:Improved 3D-printed drill guiding template can improve the accuracy of pedicle screw placement in cervical spine.