Robotic-Assisted and AR Spine Surgery Enable Equally High Degree of Precision and Accuracy, Finds Study

Pedicle screws are commonly used in spinal surgeries to stabilize the spine, and accurate placement is essential for successful outcomes. In recent years, robotic-assisted navigation (RAN) and augmented reality (AR) systems have been developed for spine surgery. RAN involves using robotic arms to guide surgeon-operated instruments with the help of 3D imaging of the patient’s anatomy and GPS-like navigation technology, allowing for minimally invasive procedures planned in advance using specialized software. On the other hand, AR-assisted spine surgery overlays 3D images of a patient’s spine onto the surgeon’s view during surgery via an augmented reality headset, with the surgery being planned using preoperative CT scans. Now, a new study comparing these two techniques found that both RAN and AR provided excellent accuracy and safety for pedicle screw placement.

The study conducted by researchers at the Hospital for Special Surgery (HSS, New York, NY, USA) involved 212 adult patients undergoing spine surgery, where a total of 1,211 pedicle screws were placed using either RAN (827 screws in 108 patients) or AR (384 screws in 104 patients) between June 2020 and October 2023. The surgeries were performed on the lumbar and/or sacral spine to treat degenerative spinal conditions. One highly experienced surgeon performed all robotic-assisted cases, while two other skilled surgeons used the AR system for the remaining surgeries. The placement of each pedicle screw was assessed after surgery using either CT scans or 3D fluoroscopy, with accuracy graded using the Gertzbein-Robbins classification system, which categorizes screw placements as A, B, C, or D.

Grades A and B were considered acceptable, with Grade A representing a screw placed entirely within the pedicle, and Grade B indicating a screw that was 2mm (1/16 inch) outside the desired position. Grades C and D were deemed unacceptable. Two independent spine surgeons evaluated the screw placements, and no significant differences were found between the two techniques. In terms of accuracy, 99.6% of screws placed using RAN were rated Grade A or B, while 98.7% of AR-placed screws received the same rating. Overall, 92.6% of screws were classified as Grade A, indicating a high level of accuracy in both methods.

“Compared to conventional free-hand techniques, both robotic-assisted navigation and the use of augmented reality have demonstrated superior accuracy. Our study is the first to directly compare RAN to AR with respect to screw placement precision,” said Darren R. Lebl, MD, MBA, a spine surgeon and director of research at HSS, and principal investigator of the study. “Our results confirmed excellent accuracy for both techniques, making both robotics and AR safe tools for accurate positioning of lumbosacral pedicle screws. However, a higher rate of Grade A screws was seen in the RAN group, potentially highlighting superior precision for robotics.”

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