Risk factor analysis of the accuracy and safety of planned and actual screw paths with robot-assisted technology

Abstract

Objective: To investigate the risk factors for deviation of the planned path from the actual screw path under robot-assisted posterior spine surgery and to evaluate the accuracy and safety of this technique. Methods: Retrospective analysis of case data from October 2021 to July 2022 for spine-related disorders seen at our spine surgery center. Univariate and multifactorial analysis of potential factors for deviations between the planned and actual screw paths with robot-assisted technology was performed, and logistic regression was used to identify independent risk factors for suboptimal screw placement. Results: A total of 820 screws were placed in these 145 patients, including 600 CBT screws and 220 pedicle screws. Screw accuracy was described using the modified Gertzbein-Robbins score, and the overall accuracy of screw placement (grades A and B) was 98.2%; unsatisfactory screw placement (C+D+E) was present in 15 cases (1.8%). Male (OR=3.723; 95% CI=2.215-6.259; p<0.01), right-sided screw placement (OR=4.023; 95% CI=2.477-6.532; p<0.001), larger axial plate angle (OR=1.069; 95% CI=1.043-1.095; p<0.001), thicker screw (OR=1.151; 95% CI=1.068 to 1.241; p<0.001), and larger tracer-to-surgical-segment distance (OR=0.159; 95% CI=0.088 to 0.288; p<0.001) all affected screw accuracy in robot-assistedsurgery. Conclusion: In the operation of robot-assisted screws, CBT or pedicle screwing may not affect the accuracy of screw placement. Placing the screw on the right side, larger laminated angles, larger diameters of the screws, and distance away from the tracker are risk factors for screw deviation from the pre-planned path, which reminds us to maintain a high degree of vigilance during surgery.

A Single-Center Experience of Robotic-Assisted Spine Surgery in Korea : Analysis of Screw Accuracy, Potential Risk Factor of Screw Malposition and Learning Curve

“…Based on previous studies 33,[36][37][38] , the potential risk factors were classified and analyzed as follows : 1) age (≥70 and <70 years old), 2) sex (male, female), 3) BMI (non-obese group, <25 kg/m 2 ; overweight group, 25 kg/m 2 ≤BMI<30 kg/m 2 ; and obese group, ≥30 kg/m 2 ), 4) BMD measured using dual-energy Xray absorptiometry at the lumbar region (non-osteopenia group, T value of >-1.0; the below osteopenia group, T value of ≤-1.0), 5) left and right screw side, 6) screw fixation level (L2, L3, L4, L5, and S1), 7) segmental distance (SD) between the tracker and the instrumented level (Fig. 4 [two, three, four, and five levels]), and 8) preoperative diagnosis (spondylolisthesis, herniated intervertebral disc [HIVD], spinal stenosis, and scoliosis).…”