Accuracy of Augmented Reality Navigation Versus Freehand Pedicle Screw Placement

Area of Science:

• Spinal surgery
• Medical technology
• Orthopedics

Background:

• Accurate pedicle screw placement is critical for effective spinal fusion.
• Augmented reality (AR) navigation offers a potential alternative to freehand (FH) techniques.
• AR may provide advantages in accuracy, efficiency, and ergonomics for spinal procedures.

Purpose of the Study:

• To compare the accuracy of AR-guided versus FH pedicle screw placement in the lumbosacral spine.
• To evaluate screw accuracy using computed tomography (CT)-based Gertzbein-Robbins (GRS) grading.
• To identify demographic and surgical factors influencing screw placement accuracy.

Main Methods:

• Retrospective cohort study analyzing 202 patients with 1,109 pedicle screws (L1-S1).
• Comparison of screw accuracy between AR-guided and FH techniques using postoperative CT scans.
• Assessment of Gertzbein-Robbins (GRS) grading for screw placement acceptability.

Main Results:

• Augmented reality (AR) group showed a significantly higher proportion of clinically acceptable screws (99.3% vs. 96.4%, P=0.013).
• Clinically unacceptable screw breaches were significantly lower in the AR group (0.7% vs. 3.6%, P=0.013).
• No significant differences in demographic or surgical characteristics were observed between the AR and FH cohorts.

Conclusions:

• AR-guided navigation demonstrated superior accuracy for pedicle screw placement compared to the FH technique.
• This study, the largest direct comparison, supports AR's potential for consistent accuracy in spinal surgery.
• Further prospective research is recommended to ascertain the long-term clinical benefits of AR navigation.