Mixed Reality Navigation Versus Computer-Assisted Navigation for Pedicle Screw Placement: A Human Specimen Accuracy Study
Fleur A. van der Kaaij, Sander J.C. Tabernée Heijtmeijer, Joep Kraeima, Christopher Faber, J. Marc C. van Dijk, Peter A.J. Pijpker, Jos M.A. KuijlenStudy Design:
Experimental human specimen study.
Objective:
To evaluate the surgical accuracy of pedicle screw placement in preserved human specimens using an in-house mixed reality (MR) navigation system compared with conventional computer-assisted navigation.
Summary of Background Data:
Pedicle screw fixation was used to obtain spinal stability and fusion in spinal conditions. Traditional surgical methods carry risks of screw malpositioning, radiation exposure, and reliance on two-dimensional navigation monitors. MR navigation enables real-time three-dimensional projection in the surgical field, potentially improving spatial orientation and surgical accuracy.
Materials and Methods:
Three Thiel-embalmed human specimens underwent CT-based pedicle screw virtual surgical planning with 3D technology. On the left side of accessible vertebral levels, 26 pedicle trajectories were drilled using conventional navigation, and 25 on the right side using MR navigation. The in-house MR navigation system superimposes color-coded circular markers directly onto the surgical field, providing immediate, monitor-free, intuitive feedback. Accuracy and efficiency were assessed using postprocedural CT-based deviation analysis (3D deviation angle and entry-point deviation), Gertzbein-Robbins classification by two observers, and navigation time. Both groups were tested for statistical significance using the independent-samples
Results:
No statistically significant differences were found between the conventional and MR groups for the 3D deviation angle (4.58±2.43
Conclusions:
MR navigation achieved surgical accuracy comparable to conventional computer-assisted navigation, indicating no concessions in safety. MR navigation reduced the median navigation time by ∼1 minute and eliminated the constant attention shift between the surgical field and the external 3D navigation monitor, offering meaningful workflow benefits. Future studies with larger cohorts and prospective clinical trials are warranted to further establish accuracy and efficacy before clinical implementation.