A recent study reports that new technology utilising augmented reality surgical navigation can be clinically used to place pedicle screws, enabling both high accuracy and an acceptable navigation time. The results were presented by Gustav Burström, Karolinska Institutet, Stockholm, Sweden, at the Eurospine 2018 annual meeting (19–21 September, Barcelona, Spain).
Burström acknowledges the recent progression of surgical techniques, “Today we see a number of trends in spine surgery; image guided surgery and navigation is widely used and widely studied, and [alongside] those, 3D imaging in the operating room is on the rise.”
He notes that the literature depicts a wide variation of accuracies reported for pedicle screw placement. For example, in meta-analyses, many studies report superiority for navigation compared to free-hand. However, this finding was not reported by all studies and cannot be extended to all indications.
For these reasons, Burström and colleagues aimed to study a specific solution to navigation and examine how it performs in complex spinal procedures. The study was performed in a hybrid operating room with an integrated augmented reality surgical navigation system encompassing a surgical table and a motorised flat detector C-arm with intraoperative 2D and 3D capabilities. Finally, integrated cameras were used both for tracking the patient and also in order to provide a video feed, allowing the investigators to superimpose the augmented reality view.
In order to assess this technology, the authors enrolled 20 patients with varying spinal indications for surgery all requiring screw placement (14 deformity cases, three spondylolisthesis and five other clinical indications).
Of the 253 pedicle screws that were placed using the AR navigation system, an overall accuracy of 94% was achieved. On average, a quarter of the procedure time corresponded to the usage of the AR system to navigate the screws, with the median time of screw placement was four minutes. During the study, no device-related adverse event occurred. Additionally, safety measures showed that the patient radiation dose ranged from 14.1 to 51.4 Gy·cm2, while the total cumulative staff occupational dose ranged from zero to 3.2µSv. According to Burström, this minimal staff dose owes to the fact that all of the personnel were behind shielding when X-ray was used.
Concluding the findings, Burström says: “This was the first ever clinical study on an augmented reality surgical system, which seems to offer a high accuracy for pedicle screw placement. Of course, further studies are needed with comparison to other techniques.”