Spine Surgery Assisted by Augmented Reality: Where Have We Been?

3D-SARC: A Pilot Study Testing the Use of a 3D Augmented-Reality Model with Conventional Imaging as a Preoperative Assessment Tool for Surgical Resection of Retroperitoneal Sarcoma

BACKGROUND

Retroperitoneal sarcomas (RPSs) present a surgical challenge, with complex anatomic relationships to organs and vascular structures. This pilot study investigated the role of three-dimensional (3D) augmented reality (3DAR) compared with standard imaging in preoperative planning and resection strategies.

METHODS

For the study, 13 patients who underwent surgical resection of their RPS were selected based on the location of their tumor (right, left, pelvis). From the patients' preoperative computed tomography (CT) scans, 3DAR models were created using a D2P program and projected by an augmented-reality (AR) glass (Hololens). The 3DAR models were evaluated by three experienced sarcoma surgeons and compared with the baseline two-dimensional (2D) contrast-enhanced CT scans.

RESULTS

Three members of the surgical team evaluated 13 models of retroperitoneal sarcomas, resulting in a total of 26 responses. When the surgical team was asked to evaluate whether the 3DAR better prepared the surgeon for planned surgical resection, 10 responses favored the 3DAR, 5 favored the 2D CT scans and 11 showed no difference (p = 0.074). According to 15 (57.6 %) of the 26 responses, the 3DAR offered additional value over standard imaging in the preoperative planning (median score of 4; range, 1-5). The median stated likelihood that the surgeons would consult the 3DAR was 5 (range, 2-5) for the preoperative setting and 3 (range, 1-5) for the intraoperative setting.

CONCLUSIONS

This pilot study suggests that the use of 3DAR may provide additional value over current standard imaging in the preoperative planning for surgical resection of RPS, and the technology merits further study.

Natural Experiments as a Study Method in Spinal Trauma Surgery: A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVES

To determine if the natural experiment design is a useful research methodology concept in spinal trauma care, and to determine if this methodology can be a viable alternative when randomized controlled trials are either infeasible or unethical.

METHODS

A Medline, Embase and Cochrane database search was performed between 2004 and 2023 for studies comparing different treatment modalities of spinal trauma. All observational studies with a natural experiment design comparing different treatment modalities of spinal trauma were included. Data extraction and quality assessment with the MINORS criteria was performed.

RESULTS

Four studies with a natural experiment design regarding patients with traumatic spinal fractures were included. All studies were retrospective, one study collected follow-up data prospectively. Three studies compared different operative treatment modalities, whereas one study compared different antibiotic treatment strategies. Two studies compared preferred treatment modalities between expertise centers, one study between departments (neuro- and orthopedic surgery) and one amongst surgeons. For the included retrospective studies, MINORS scores (maximum score 18) were high ranging from 12-17 and with a mean (SD) of 14.6 (1.63).

CONCLUSIONS

Since 2004 only four studies using a natural experiment design have been conducted in spinal trauma. In the included studies, comparability of patient groups was high emphasizing the potential of natural experiments in spinal trauma research. Natural experiments design should be considered more frequently in future research in spinal trauma as they may help to address difficult clinical problems when RCT's are infeasible or unethical.

Analysis of the Screw Accuracy and Postoperative Efficacy of Screw Placement in Single Position and Bipedal Position in Robot-Assisted Oblique Lumbar Interbody Fusion: Preliminary Results of Mazor X Stealth Usage

OBJECTIVE

Traditional manual OLIF combined with pedicle screw implantation has many problems of manual percutaneous screw implantation, such as high difficulty of screw placement, many fluoroscopies, long operation time, and many adjustments, resulting in greater trauma. The robot can perform various types of screw placement in the lateral recumbent position, which allows OLIF combined with posterior screw placement surgery to be completed in a single position. To compare the screw accuracy and initial postoperative results of oblique anterior lumbar fusion with robot-assisted screw placement in the lateral position and screw placement in the prone position for the treatment of lumbar spondylolisthesis.

METHODS

From May to June 2022, 45 patients with single-segment lumbar spondylolisthesis underwent Mazor X-assisted oblique lumbar fusion in one position and Renaissance-assisted surgery in two different positions, and screw accuracy was assessed on computed tomography scans according to a modified Gertzbein-Robbins classification. Patients were divided into a single position group and a bipedal position group (the lateral position for complete oblique lumbar fusion and then changed to the prone position for posterior screw placement), and the perioperative parameters, including operative time, number of fluoroscopies, and operative complications, were recorded separately. The results of the clinical indicators, such as the visual analog scale (VAS) for back and leg pain and the Oswestry Disability Index (ODI) score, were obtained.

RESULTS

There were no significant differences in the patients' demographic data between the two groups. The single position group had a shorter operative time and fewer fluoroscopies than the bipedal position group; the single position group had a higher percentage of screw accuracy at the A level than the bipedal position group, but there was no statistically significant difference between the two groups at the acceptable level (A + B) (p > 0.05). The single-position group had better outcomes at the 1-week postoperative follow-up back pain VAS scores (p < 0.05). There was no statistically significant difference in the postoperative leg pain VAS scores or the ODI scores when compared to the control group.

CONCLUSION

Robot-assisted lateral position oblique lumbar interbody fusion with pedicle screw placement has the same accuracy as prone positioning. Single position surgery can significantly shorten the operation time and reduce the fluoroscopy. There was no significant difference in the long-term efficacy between the two groups.

Machine Learning in Spine Surgery: A Narrative Review

Artificial intelligence and machine learning (ML) can offer revolutionary advances in their application to the field of spine surgery. Within the past 5 years, novel applications of ML have assisted in surgical decision-making, intraoperative imaging and navigation, and optimization of clinical outcomes. ML has the capacity to address many different clinical needs and improve diagnostic and surgical techniques. This review will discuss current applications of ML in the context of spine surgery by breaking down its implementation preoperatively, intraoperatively, and postoperatively. Ethical considerations to ML and challenges in ML implementation must be addressed to maximally benefit patients, spine surgeons, and the healthcare system. Areas for future research in augmented reality and mixed reality, along with limitations in generalizability and bias, will also be highlighted.

Advances in surgical treatment for atlantoaxial instability focusing on rheumatoid arthritis: Analysis of a series of 67 patients

AIM

An estimated 88% of rheumatoid arthritis (RA) patients experience various degrees of cervical spine involvement. The excessive movement of the atlantoaxial joint, which connects the occiput to the upper cervical spine, results in atlantoaxial instability (AAI). AAI stabilization is usually achieved by C1 lateral mass-to-C2 pedicle screw-rod fixation (LC1-PC2 fixation), which is technically challenging in RA patients who often show destructive changes in anatomical structures. This study aimed to analyze the clinical results and operative experiences of C1-C2 surgery, with emphasis on the advancement of image-guided surgery and augmented reality (AR) assisted navigation.

METHODS

We presented our two decades of experience in the surgical management of AAI from April 2004 to November 2022.

RESULTS

We have performed surgery on 67 patients with AAI, including 21 traumatic odontoid fractures, 20 degenerative osteoarthritis, 11 inflammatory diseases of RA, 5 congenital anomalies of the os odontoideum, 2 unknown etiologies, 2 movement disorders, 2 previous implant failures, 2 osteomyelitis, 1 ankylosing spondylitis, and 1 tumor. Beginning in 2007, we performed LC1-PC2 fixation under C-arm fluoroscopy. As part of the progress in spinal surgery, since 2011 we used surgical navigation from presurgical planning to intraoperative navigation, using the preoperative computed tomography (CT) -based image-guided BrainLab navigation system. In 2021, we began using intraoperative CT scan and microscope-based AR navigation.

CONCLUSION

The technical complexities of C1-C2 surgery can be mitigated by CT-based image-guided surgery and microscope-based AR navigation, to improve accuracy in screw placement and overall clinical outcomes, particularly in RA patients with AAI.

Augmented Reality in Neurosurgery: A New Paradigm for Training

Augmented reality (AR) involves the overlay of computer-generated images onto the user's real-world visual field to modify or enhance the user's visual experience. With respect to neurosurgery, AR integrates preoperative and intraoperative imaging data to create an enriched surgical experience that has been shown to improve surgical planning, refine neuronavigation, and reduce operation time. In addition, AR has the potential to serve as a valuable training tool for neurosurgeons in a way that minimizes patient risk while facilitating comprehensive training opportunities. The increased use of AR in neurosurgery over the past decade has led to innovative research endeavors aiming to develop novel, more efficient AR systems while also improving and refining present ones. In this review, we provide a concise overview of AR, detail current and emerging uses of AR in neurosurgery and neurosurgical training, discuss the limitations of AR, and provide future research directions. Following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), 386 articles were initially identified. Two independent reviewers (GH and AC) assessed article eligibility for inclusion, and 31 articles are included in this review. The literature search included original (retrospective and prospective) articles and case reports published in English between 2013 and 2023. AR assistance has shown promise within neuro-oncology, spinal neurosurgery, neurovascular surgery, skull-base surgery, and pediatric neurosurgery. Intraoperative use of AR was found to primarily assist with surgical planning and neuronavigation. Similarly, AR assistance for neurosurgical training focused primarily on surgical planning and neuronavigation. However, studies included in this review utilize small sample sizes and remain largely in the preliminary phase. Thus, future research must be conducted to further refine AR systems before widespread intraoperative and educational use.

Technological Advances in Spine Surgery: Navigation, Robotics, and Augmented Reality

Accurate screw placement is critical to avoid vascular or neurologic complications during spine surgery and to maximize fixation for fusion and deformity correction. Computer-assisted navigation, robotic-guided spine surgery, and augmented reality surgical navigation are currently available technologies that have been developed to improve screw placement accuracy. The advent of multiple generations of new technologies within the past 3 decades has presented surgeons with a diverse array of choices when it comes to pedicle screw placement. Considerations for patient safety and optimal outcomes must be paramount when selecting a technology.

Augmented Reality-Assisted Navigation System for Transforaminal Epidural Injection

Purpose

Multiple studies have attempted to demonstrate the benefits of augmented reality (AR)-assisted navigation systems in surgery. Lumbosacral transforaminal epidural injection is an effective treatment commonly used in patients with radiculopathy due to spinal degenerative pathologies. However, few studies have applied AR-assisted navigation systems to this procedure. The study aimed to investigate the safety and effectiveness of an AR-assisted navigation system for transforaminal epidural injection.

Patients and Methods

Through a real-time tracking system and a wireless network to the head-mounted display, computed tomography images of the spine and the path of a spinal needle to the target were visualized on a torso phantom with respiration movements installed. From L1/L2 to L5/S1, needle insertions were performed using an AR-assisted system on the left side of the phantom, and the conventional method was performed on the right side.

Results

The procedure duration was approximately three times shorter, and the number of radiographs required was reduced in the experimental group compared to the control group. The distance from the needle tips to the target areas in the plan showed no significant difference between the two groups. (AR group 1.7 ± 2.3mm, control group 3.2 ± 2.8mm, P value 0.067).

Conclusion

An AR-assisted navigation system may be used to reduce the time required for spinal interventions and ensure the safety of patients and physicians in view of radiation exposure. Further studies are essential to apply AR-assisted navigation systems to spine interventions.

Innovation in Neurosurgery: Lessons Learned, Obstacles, and Potential Funding Sources

Innovation is central to neurosurgery and has dramatically increased over the last twenty years. Although the specialty innovates as a whole, only 3-4.7% of practicing neurosurgeons hold patents. Various roadblocks to innovation impede this process such as lack of understanding, increasing regulatory complexity, and lack of funding. Newly emerging technologies allow us to understand how to innovate and how to learn from other medical specialties. By further understanding the process of innovation, and the funding that supports it, Neurosurgery can continue to hold innovation as one of its's central tenets.

State of the Art and Future Prospects of Virtual and Augmented Reality in Veterinary Medicine: A Systematic Review

Virtual reality and augmented reality are new but rapidly expanding topics in medicine. In virtual reality, users are immersed in a three-dimensional environment, whereas in augmented reality, computer-generated images are superimposed on the real world. Despite advances in human medicine, the number of published articles in veterinary medicine is low. These cutting-edge technologies can be used in combination with existing methods in veterinary medicine to achieve diagnostic/therapeutic and educational goals. The purpose of our review was to evaluate studies for their use of virtual reality and augmented reality in veterinary medicine, as well as human medicine with animal trials, to report results and the state of the art. We collected all of the articles we included in our review by screening the Scopus, PubMed, and Web of Science databases. Of the 24 included studies, 11 and 13 articles belonged to virtual reality and augmented reality, respectively. Based on these articles, we determined that using these technologies has a positive impact on the scientific output of students and residents, can reduce training costs, and can be used in training/educational programs. Furthermore, using these tools can promote ethical standards. We reported the absence of standard operation protocols and equipment costs as study limitations.