Face, Content, Construct and Convergent Validity of a Surgical Spine Simulator for Pedicle Screw Insertions.

Abstract

Background: Spine simulators offer learners risk-free environments to develop psychomotor skills for pedicle screw insertions. The virtual reality TSYM simulator deconstructs and simulates pedicle screw insertions. This case series study investigates face, content, construct, and convergent validity of an L4-L5 bilateral pedicle screw insertion on the TSYM simulator.

Methods: Neurosurgical-orthopedic residents, fellows, and spine surgeons performed an L4-L5 bilateral pedicle screw insertion on the TSYM simulator. Participants were classified a priori into skilled (postgraduate year (PGY) 5-6, fellows, and consultant neurosurgeons or orthopedic surgeons) or less skilled (PGY 1-4) groups. Face and content validity were assessed utilizing a 7-point Likert scale. Construct validity was determined by investigating group differences in simulation-derived performance metrics and the Objective Structured Assessment of Technical Skills (OSATS) ratings. Convergent validity was examined by correlating simulation-derived performance metrics and OSATS ratings.

Results: Thirteen skilled and 14 less skilled participants were included in this study. Eight of nine face and content validity statements were rated a median ≥ 4. Significant differences between the groups were found for four simulation-derived performance metrics (P < 0.05) and all OSATS categories (P < 0.001). Three simulation-derived performance metrics (maximum force and tool contact using the simulated screwdriver and three-dimensional velocity using the tap) significantly correlated with OSATS ratings.

Conclusion: The L4-L5 bilateral pedicle screw insertion simulation on the TSYM platform demonstrated mixed and variable evidence for face, content, construct and convergent validity, supporting its educational potential for spine surgery training, but improvements are needed to optimize learning.