Objective To evaluate the precision of robot-assisted axis pedicle screw placement and to evaluate the fac-tors influencing the accuracy of the placement.Methods The medical records of 27 consecutive patients who underwent posteri-or internal fixation of the upper cervical spine for atlantoaxial instability with intraoperative robot-assisted axis pedicle screw placement from January 2017 to December 2020 at Beijing Jishuitan Hospital were retrospectively analyzed.T The cohort com-prised 10 males and 17 females,aged 41.3±16.6 years(range 12-75 years),with a body mass index(BMI)of 23.0±2.9 kg/m2(range 18.9-30.0 kg/m2).There were 16 cases of traumatic atlantoaxial instability and 11 cases of atlantoaxial instability caused by deformity.The accuracy of robot-assisted axis pedicle screw placement was evaluated by postoperative CT using Gertzbein-Rob-bins scale.Factors potentially affecting placement accuracy were initially identified via univariate analysis,with significant factors(P＜0.200)subsequently analyzed through multivariate modeling using generalized estimating equations.Results A total of 49 ax-is pedicle screws were placed in 27 patients,with 35(71.4％)in Gertzbein-Robbins scale grade A,12(24.5％)in grade B,2(4.1％)in e grade C,and 0 in grades D and E.The clinically acceptable rate(Gertzbein-Robbins grades A and B)was 95.9％.No patient experienced vascular or neurologic injury due to screw displacement.The results of univariate analysis showed no statisti-cal significance for patient factors(age,gender,BMI,preoperative cervical curvature,and causes of atlantoaxial instability);no sta-tistical significance for the surgical factors of tracker position,screw position,screw type,and screw placement approach(P＞0.05),and a statistically significant difference for the difference between the effective width of the axis pedicle and the screw diameter(t=3.484,P＜0.001).The results of multifactorial analysis showed that tracker fixation to the Mayfield frame in robot-assisted axis ped-icle screw placement over the axis spinous process resulted in more accurate screw placement[OR=83.231,95％CI(3.898,1776.952),P=0.005];and the greater the difference between the effective width of the axis pedicle and the diameter of the screw,the greater the accuracy of screw placement[OR=5.330,95％CI(1.648,17.243),P=0.005].Conclusion Robot-assisted axis pedicle screw placement is both precise and safe.Securing the tracker to the Mayfield clamp rather than the axis spinous process enhances the accuracy of screw placement.A greater discrepancy between the axis pedicle's effective width and the screw diame-ter decreases the likelihood of cortical violation.Preoperative planning,including the selection of appropriate screw types and ad-justing the trajectory in three dimensions to maximize the difference between the pedicle's effective width and the screw diameter,can mitigate the risk of cortical breach and subsequent vascular and neurological injury.
关键词
枢椎,颈椎/机器人手术/椎弓根钉/影响因素分析
Key words
Axis,cervical vertebra/Robotic surgical procedures/Pedicle screws/Root cause analysis
维普
万方数据