Study design: Cadaveric study.
Objective: This cadaveric study sought to evaluate the efficacy of disc space preparation with cone beam-computed tomography with navigation (CBCT+N) for instrument placement compared with instrument placement with conventional fluoroscopy.
Summary of background data: Disc space preparation from a transforaminal lumbar approach is challenging with respect to visualization, and surgeons currently rely on tactile feel and two-dimensional imaging in the operating room to assess instrument positioning.
Methods: Two orthopedic spine surgeons performed 40 disc space preparations after eight cadavers were randomly assigned to fluoroscopy versus CBCT+N. Digital images of each vertebral endplate were captured and the percent disc removed by area for the total disc and by quadrants was determined using digital imaging software.
Results: There were 20 lumbar disc levels prepared in the fluoroscopy group. There were 3 thoracolumbar, and 17 lumbar disc levels prepared in the experimental group. Percent disc removed relative to the total area of the disc, as determined by the digital imaging software, was higher in the CBCT+N group (P ≤ 0.0001). More disc was removed in both the anterior contralateral and posterior contralateral quadrants in the CBCT+N group (P = 0.0006 and P ≤ 0.0001 respectively). The intraclass correlation coefficient among blinded reviewers for percent disc removed was 0.759 (95% confidence interval, 0.587-0.866)]. There was no difference in time to complete disc space preparation, number of instrument passes, or number of endplate violations between the two groups (P = 0.28, P = 0.92, and P = 0.34 respectively).
Conclusion: The results of this cadaveric investigation reveal that CBCT+N guidance may be used to assess instrument placement for interbody disc space preparation in a similar length of time, with no difference in instrument passes or endplate violations, in comparison with fluoroscopy.
Level of evidence: 5.