Augmented reality–assisted pedicle screw insertion: a cadaveric proof-of-concept study

Abstract

<jats:sec><jats:title>OBJECTIVE</jats:title><jats:p>Augmented reality (AR) is a novel technology that has the potential to increase the technical feasibility, accuracy, and safety of conventional manual and robotic computer-navigated pedicle insertion methods. Visual data are directly projected to the operator’s retina and overlaid onto the surgical field, thereby removing the requirement to shift attention to a remote display. The objective of this study was to assess the comparative accuracy of AR-assisted pedicle screw insertion in comparison to conventional pedicle screw insertion methods.</jats:p></jats:sec><jats:sec><jats:title>METHODS</jats:title><jats:p>Five cadaveric male torsos were instrumented bilaterally from T6 to L5 for a total of 120 inserted pedicle screws. Postprocedural CT scans were obtained, and screw insertion accuracy was graded by 2 independent neuroradiologists using both the Gertzbein scale (GS) and a combination of that scale and the Heary classification, referred to in this paper as the Heary-Gertzbein scale (HGS). Non-inferiority analysis was performed, comparing the accuracy to freehand, manual computer-navigated, and robotics-assisted computer-navigated insertion accuracy rates reported in the literature. User experience analysis was conducted via a user experience questionnaire filled out by operators after the procedures.</jats:p></jats:sec><jats:sec><jats:title>RESULTS</jats:title><jats:p>The overall screw placement accuracy achieved with the AR system was 96.7% based on the HGS and 94.6% based on the GS. Insertion accuracy was non-inferior to accuracy reported for manual computer-navigated pedicle insertion based on both the GS and the HGS scores. When compared to accuracy reported for robotics-assisted computer-navigated insertion, accuracy achieved with the AR system was found to be non-inferior when assessed with the GS, but superior when assessed with the HGS. Last, accuracy results achieved with the AR system were found to be superior to results obtained with freehand insertion based on both the HGS and the GS scores. Accuracy results were not found to be inferior in any comparison. User experience analysis yielded “excellent” usability classification.</jats:p></jats:sec><jats:sec><jats:title>CONCLUSIONS</jats:title><jats:p>AR-assisted pedicle screw insertion is a technically feasible and accurate insertion method.</jats:p></jats:sec>

Augmented reality-based navigation increases precision of pedicle screw insertion

“…Three-dimensional navigation proved to be of use not only in patients with but particularly when treating spinal deformity [25,26]. Although similar clinical results are currently missing, AR-based navigation techniques already demonstrated remarkable precision in an experimental setting [27]. As a result of different approaches of measuring precision and accuracy, an exact comparison of specific studies is not useful.…”

“…However, projecting the required information directly into the line of sight of the surgeon is considered the natural progression of these well-established methods mitigating the errors associated with attention shift by directly projecting the navigation guidance onto the surgical field [27,28].…”

“…In a real operating room setting, the described registration approach would be impractical. Various methods of registration have been described including ultrasound-based techniques, reflective markers mounted on spinous processes, and non-invasive skin placed markers [27][28][29]. However, further research is currently being undertaken to facilitate automation of the process, and with advancements of technology in the future, the use of dedicated markers might be obsolete.…”

Robotic Spine Surgery and Augmented Reality Systems: A State of the Art

“…In a proof-of-concept cadaveric study, the use of xvision resulted in 98.9% percutaneous screw placement accuracy and reduced the need of continuous shift from the operating field to separate screens to visualize procedure-related key information. 68 The employment of AR has also found a possible application in microscope-based MISS. In fact, by using the heads-up displays of the operating microscope, a 3D representation of vertebrae and implants from preoperative imaging was superimposed to the microscope video and implemented with navigation in 2 recent studies on spinal tumors 69 and degenerative spine disease.…”

Finding NEEMO: towards organizing smart digital solutions in orthopaedic trauma surgery

“… 11 This can further be simplified by the use of head-mounted displays to relay information into the surgeon’s field of view. 12 Apart from the commercially available systems, clinically focused research in this field aims to reduce the amount of radiation exposure and markers, 13 incorporating standard systems and technologies into user interfaces and also in using AR to relay not only bony, but also soft tissue and vascular anatomy to the surgeon’s field of view. 14 Apart from intraoperative use, this technology can also be used for surgical planning with VR and AR assisted planning of reduction and hardware position, as well as hardware templating in a virtual environment.…”