Evaluation of robot-guided minimally invasive implantation of 2067 pedicle screws

20-year Inflation-Adjusted Medicare Reimbursements (Years: 2000-2020) For Common Lumbar and Cervical Degenerative Disc Disease Procedures

OBJECTIVE

Reimbursement trends for common procedures have persistently declined over the past 2 decades. Spinal instrumentational and fusion procedures are increasingly utilized and have increased in clinical complexity, yet longitudinal inflation-adjusted data for Medicare reimbursements of these procedures have not been evaluated.

METHODS

The Centers for Medicare and Medicaid Services (CMS) Physician Fee Schedule Look-Up Tool was used to extract Medicare reimbursements for the 5 most common spinal procedures and associated instrumentations from 2000-2020. Current Procedural Terminology (CPT) codes include 22551, 22600, 22633, 63030, and 63047 as well as instrumentation CPT codes 22840 and 22842-6. The nominal values were adjusted for inflation according to the latest consumer price index (U.S. Bureau of Labor Statistics; reported as 2020 USD) and used to calculate average annual percent changes and compound annual growth rates (CAGRs) in reimbursements.

RESULTS

After inflation adjustment, the physician fee reimbursement decreased by 11.05% ± 8.46% (mean ± s.d., from $2,009.89 in 2011 to $1,787.85 in 2020) for anterior cervical discectomy and fusion (ACDF), 28.38% ± 8.42% (from $1,889.38 in 2000 to $1,353.14 in 2020) for posterior cervical fusion, 7.85% ± 8.20% (from $2,111.20 in 2012 to $1,945.49 in 2020) for transforaminal lumbar interbody fusion (TLIF), 28.17% ± 13.88% (from $1,421.78 in 2000 to $1,021.22 in 2020) for lower back disc surgery, and 31.88% ± 8.22% (from $1,700.38 in 2000 to $1,158.25 in 2020) for lumbar laminectomy. Instrumentation reimbursements showed an average decrease of 33.43% ± 8.4% over this period. Average CAGR was -1.7% ± .41% for procedures and -2.02% ± .14% for instrumentation.

CONCLUSION

Our analysis reveals a persistent decline in reimbursement rates of the most common spine procedures and instrumentation since the year 2000. If unaddressed, this trend can serve as a substantial disincentive for physicians to perform these procedures and can significantly limit access to spinal care at the population level.

Trends in usage of navigation and robotic assistance in elective spine surgeries: a study of 105,212 cases from 2007 to 2015

OBJECTIVE

Identify trends of navigation and robotic-assisted elective spine surgeries.

METHODS

Elective spine surgery patients between 2007 and 2015 in the Nationwide Inpatient Sample (NIS) were isolated by ICD-9 codes for Navigation [Nav] or Robotic [Rob]-Assisted surgery. Basic demographics and surgical variables were identified via chi-squared and t tests. Each system was analyzed from 2007 to 2015 for trends in usage.

RESULTS

Included 3,759,751 patients: 100,488 Nav; 4724 Rob. Nav were younger (56.7 vs 62.7 years), had lower comorbidity index (1.8 vs 6.2, all p < 0.05), more decompressions (79.5 vs 42.6%) and more fusions (60.3 vs 52.6%) than Rob. From 2007 to 2015, incidence of complication increased for Nav (from 5.8 to 21.7%) and Rob (from 3.3 to 18.4%) as well as 2-3 level fusions (from 50.4 to 52.5%) and (from 1.3 to 3.2%); respectively. Invasiveness increased for both (Rob: from 1.7 to 2.2; Nav: from 3.7 to 4.6). Posterior approaches (from 27.4 to 41.3%), osteotomies (from 4 to 7%), and fusions (from 40.9 to 54.2%) increased in Rob. Anterior approach for Rob decreased from 14.9 to 14.4%. Nav increased posterior (from 51.5% to 63.9%) and anterior approaches (from 16.4 to 19.2%) with an increase in osteotomies (from 2.1 to 2.7%) and decreased decompressions (from 73.6 to 63.2%).

CONCLUSIONS

From 2007 to 2015, robotic and navigation systems have been performed on increasingly invasive spine procedures. Robotic systems have shifted from anterior to posterior approaches, whereas navigation computer-assisted procedures have decreased in rates of usage for decompression procedures.

The role of robotic surgery in neurological cases: A systematic review on brain and spine applications

The application of robotic surgery technologies in neurological surgeries resulted in some advantages compared to traditional surgeries, including higher accuracy and dexterity enhancement. Its success in various surgical fields, especially in urology, cardiology, and gynecology surgeries was reported in previous studies, and similar advantages in neurological surgeries are expected. Surgeries in the central nervous system with the pathology of millimeters through small working channels around vital tissue need especially high precision. Applying robotic surgery is therefore an interesting dilemma for these situations. This article reviews various studies published on the application of brain and spine robotic surgery and discusses the current application of robotic technology in neurological cases.

Complications Have Not Improved With Newer Generation Robots

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The purpose of this study was to see whether upgrades in newer generation robots improve safety and clinical outcomes following spine surgery.

METHODS

All patients undergoing robotic-assisted spine surgery with the Mazor X Stealth EditionTM (Medtronic, Minneapolis, MN) from 2019 to 2022 at a combined orthopedic and neurosurgical spine service were retrospectively reviewed. Robot related complications were recorded.

RESULTS

264 consecutive patients (54.1% female; age at time of surgery 63.5 ± 15.3 years) operated on by 14 surgeons were analyzed. The average number of instrumented levels with robotics was 4.2 ± 2.7, while the average number of instrumented screws with robotics was 8.3 ± 5.3. There was a nearly 50/50 split between an open and minimally invasive approach. Six patients (2.2%) had robot related complications. Three patients had temporary nerve root injuries from misplaced screws that required reoperation, one patient had a permanent motor deficit from the tap damaging the L1 and L2 nerve roots, one patient had a durotomy from a misplaced screw that required laminectomy and intra-operative repair, and one patient had a temporary sensory L5 nerve root injury from a drill. Half of these complications (3/6) were due to a reference frame error. In total, four patients (1.5%) required reoperation to fix 10 misplaced screws.

CONCLUSION

Despite newer generation robots, robot related complications are not decreasing. As half the robot related complications result from reference frame errors, this is an opportunity for improvement.

Pedicle Screw Placement Accuracy in Robot-Assisted Spinal Fusion in a Multicenter Study

Pedicle screw fixation is a spinal fusion technique that involves the implantation of screws into vertebral pedicles to restrict movement between those vertebrae. The objective of this research is to measure pedicle screw placement accuracy using a novel automated measurement system that directly compares the implanted screw location to the planned target in all three anatomical views. Preoperative CT scans were used to plan the screw trajectories in 122 patients across four surgical centers. Postoperative scans were fused to the preoperative plan to quantify placement accuracy using an automated measurement algorithm. The mean medial-lateral and superior-inferior deviations in the pedicle region for 500 screws were 1.75 ± 1.36 mm and 1.52 ± 1.26 mm, respectively. These deviations were measured using an automated system and were statistically different from manually determined values. The uncertainty associated with the fusion of preoperative to postoperative images was also quantified to better understand the screw-to-plan accuracy results. This study uses a novel automated measurement system to quantify screw placement accuracy as it relates directly to the planned target location, instead of analyzing for breaches of the pedicle, to quantify the validity of using of a robotic-guidance system for accurate pedicle screw placement.

Three-Dimensional Quantitative Assessment of Pedicle Screw Accuracy in Clinical Utilization of a New Robotic System in Spine Surgery: A Multicenter Study

OBJECTIVE

The objective of this study was to evaluate the accuracy of pedicle screw placement in patients undergoing percutaneous pedicle screw fixation with robotic guidance, using a newly developed 3-dimensional quantitative measurement system. The study also aimed to assess the clinical feasibility of the robotic system in the field of spinal surgery.

METHODS

A total of 113 patients underwent pedicle screw insertion using the CUVIS-spine pedicle screw guide system (CUREXO Inc.). Intraoperative O-arm images were obtained, and screw insertion pathways were planned accordingly. Image registration was performed using paired-point registration and iterative closest point methods. The accuracy of the robotic-guided pedicle screw insertion was assessed using 3-dimensional offset calculation and the Gertzbein-Robbins system (GRS).

RESULTS

A total of 448 screws were inserted in the 113 patients. The image registration success rate was 95.16%. The average error of entry offset was 2.86 mm, target offset was 2.48 mm, depth offset was 1.99 mm, and angular offset was 3.07°. According to the GRS grading system, 88.39% of the screws were classified as grade A, 9.60% as grade B, 1.56% as grade C, 0.22% as grade D, and 0.22% as grade E. Clinically acceptable screws (GRS grade A or B) accounted for 97.54% of the total, with no reported neurologic complications.

CONCLUSION

Our study demonstrated that pedicle screw insertion using the novel robot-assisted navigation method is both accurate and safe. Further prospective studies are necessary to explore the potential benefits of this robot-assisted technique in comparison to conventional approaches.

Is There a Difference in Screw Accuracy, Robot Time Per Screw, Robot Abandonment, and Radiation Exposure Between the Mazor X and the Renaissance? A Propensity-Matched Analysis of 1179 Robot-Assisted Screws

STUDY DESIGN

Prospective single-cohort analysis.

OBJECTIVES

To compare the outcomes/complications of 2 robotic systems for spine surgery.

METHODS

Adult patients (≥18-years-old) who underwent robot-assisted spine surgery from 2016-2019 were assessed. A propensity score matching (PSM) algorithm was used to match Mazor X to Renaissance cases. Preoperative CT scan for planning and an intraoperative O-arm for screw evaluation were preformed. Outcomes included screw accuracy, robot time/screw, robot abandonment, and radiation. Screw accuracy was measured using Vitrea Core software by 2 orthopedic surgeons. Screw breach was measured according to the Gertzbein/Robbins classification.

RESULTS

After PSA, a total of 65 patients (Renaissance: 22 vs. X: 43) were included. Patient/operative factors were similar between robot systems (P > .05). The pedicle screw accuracy was similar between robots (Renaissance: 1.1%% vs. X: 1.3%, P = .786); however, the S2AI screw breach rate was significantly lower for the X (Renaissance: 9.5% vs. X: 1.2%, P = .025). Robot time per screw was not statistically different (Renaissance: 4.6 minutes vs. X: 3.9 minutes, P = .246). The X was more reliable with an abandonment rate of 2.3% vs. Renaissance:22.7%, P = .007. Radiation exposure were not different between robot systems. Non-robot related complications including dural tear, loss of motor/sensory function, and blood transfusion were similar between robot systems.

CONCLUSION

This is the first comparative analyses of screw accuracy, robot time/screw, robot abandonment, and radiation exposure between the Mazor X and Renaissance systems. There are substantial improvements in the X robot, particularly in the perioperative planning processes, which likely contribute to the X's superiority in S2AI screw accuracy by nearly 8-fold and robot reliability by nearly 10-fold.

Effects of tracer position on screw placement technique in robot-assisted posterior spine surgery: a case-control study

INTRODUCTION

Robot-assisted spine surgery is increasingly used in clinical work, and the installation of tracers as a key step in robotic surgery has rarely been studied.

OBJECTIVE

To explore the potential effects of tracers on surgical outcomes in robot-assisted posterior spine surgery.

METHODS

We reviewed all patients who underwent robotic-assisted posterior spine surgery at Beijing Shijitan Hospital over a 2-year period from September 2020 to September 2022. Patients were divided into two groups based on the location of the tracer (iliac spine or vertebral spinous process) during robotic surgery and a case-control study was conducted to determine the potential impact of tracer location on the surgical procedure. Data analysis was performed using SPSS.25 statistical software (SPSS Inc., Chicago, Illinois).

RESULTS

A total of 525 pedicle screws placed in 92 robot-assisted surgeries were analyzed. The rate of perfect screw positioning was 94.9% in all patients who underwent robot-assisted spine surgery (498/525). After grouping studies based on the location of tracers, we found there was no significant difference in age, sex, height and body weight between the two groups. The screw accuracy (p < 0.01)was significantly higher in the spinous process group compared to the iliac group (97.5% versus 92.6%), but the operation time (p = 0.09) was longer in comparison.

CONCLUSION

Placing the tracer on the spinous process as opposed to the iliac spine may result in longer procedure duration or increased bleeding, but enhanced satisfaction of screw placement.

A Retrospective Analysis of Pedicle Screw Placement Accuracy Using the ExcelsiusGPS Robotic Guidance System: Case Series

BACKGROUND

Robotic guidance has become widespread in spine surgery. Although the intent is improved screw placement, further system-specific data are required to substantiate this intention for pedicle screws in spinal stabilization constructs.

OBJECTIVE

To determine the accuracy of pedicle screws placed with the aid of a robot in a cohort of patients immediately after the adoption of the robot-assisted surgery technique.

METHODS

A retrospective, Institutional Review Board-approved study was performed on the first 100 patients at a single facility, who had undergone spinal surgeries with the use of robotic techniques. Pedicle screw accuracy was graded using the Gertzbein-Robbins Scale based on pedicle wall breach, with grade A representing 0 mm breach and successive grades increasing breach thresholds by 2 mm increments. Preoperative and postoperative computed tomography scans were also used to assess offsets between the objective plan and true screw placements.

RESULTS

A total of 326 screws were analyzed among 72 patients with sufficient imaging data. Ages ranged from 21 to 84 years. The total accuracy rate based on the Gertzbein-Robbins Scale was 97.5%, and the rate for each grade is as follows: A, 82%; B, 15.5%; C, 1.5%; D, 1%; and E, 0. The average tip offset was 1.9 mm, the average tail offset was 2.0 mm, and the average angular offset was 2.6°.

CONCLUSION

Robotic-assisted surgery allowed for accurate implantation of pedicle screws on immediate adoption of this technique. There were no complications attributable to the robotic technique, and no hardware revisions were required.

Artificial intelligence in spine surgery

The continuous progress of research and clinical trials has offered a wide variety of information concerning the spine and the treatment of the different spinal pathologies that may occur. Planning the best therapy for each patient could be a very difficult and challenging task as it often requires thorough processing of the patient's history and individual characteristics by the clinician. Clinicians and researchers also face problems when it comes to data availability due to patients' personal information protection policies. Artificial intelligence refers to the reproduction of human intelligence via special programs and computers that are trained in a way that simulates human cognitive functions. Artificial intelligence implementations to daily clinical practice such as surgical robots that facilitate spine surgery and reduce radiation dosage to medical staff, special algorithms that can predict the possible outcomes of conservative versus surgical treatment in patients with low back pain and disk herniations, and systems that create artificial populations with great resemblance and similar characteristics to real patients are considered to be a novel breakthrough in modern medicine. To enhance the body of the related literature and inform the readers on the clinical applications of artificial intelligence, we performed this review to discuss the contribution of artificial intelligence in spine surgery and pathology.

Robot-assisted percutaneous vertebroplasty for osteoporotic vertebral compression fractures: a retrospective matched-cohort study

PURPOSE

This study aims to introduce the principle, clinical efficacy, and learning curve of robot-assisted percutaneous vertebroplasty (PVP).

METHODS

Forty-two patients who underwent robot-assisted single-level PVP were analyzed retrospectively and 42 age-matched patients using freehand technique were selected as the control group. The visual analog scale, operation time, radiation exposure, accuracy, and learning curve were analyzed.

RESULTS

The puncture time and total operation time were significantly shorter, and the puncture and total fluoroscopy number were fewer in the robot group. The deviation between pre-operative planned and actual puncture trajectory well met clinical requirement. The puncture time, total operation time, and puncture fluoroscopy number were significantly more in early cases than in later cases in the robot group.

CONCLUSION

The robot-assisted pedicle puncture technique shortens the operation time and reduces radiation exposure, and the accuracy meets the clinical requirement in PVP. The learning curve is short and not steep.

Basis for error in stereotactic and computer-assisted surgery in neurosurgical applications: literature review

Technological advancements in optoelectronic motion capture systems have allowed for the development of high-precision computer-assisted surgery (CAS) used in cranial and spinal surgical procedures. Errors generated sequentially throughout the chain of components of CAS may have cumulative effect on the accuracy of implant and instrumentation placement - potentially affecting patient outcomes. Navigational integrity and maintenance of fidelity of optoelectronic data is the cornerstone of CAS. Error reporting measures vary between studies. Understanding error generation, mechanisms of propagation, and how they relate to workflow can assist clinicians in error mitigation and improve accuracy during navigation in neurosurgical procedures. Diligence in planning, fiducial positioning, system registration, and intra-operative workflow have the potential to improve accuracy and decrease disparity between planned and final instrumentation and implant position. This study reviews the potential errors associated with each step in computer-assisted surgery and provides a basis for disparity in intrinsic accuracy versus achieved accuracy in the clinical operative environment.

Index Surgery Cost of Fluoroscopic Freehand Versus Robotic-Assisted Pedicle Screw Placement in Lumbar Instrumentation: An Age, Sex, and Approach-Matched Cohort Comparison

BACKGROUND

Spine surgery costs are notoriously high, and there are already criticisms and concerns over the economic effects. There is no consensus on cost variation with robot-assisted spine fusion (rLF) compared with a manual fluoroscopic freehand (fLF) approach. This study looks to compare the early costs between the robotic method and the freehand method in lumbar spine fusion.

METHODS

rLFs by one spine surgeon were age, sex, and approach-matched to fLF procedures by another spine surgeon. Variable direct costs, readmissions, and revision surgeries within 90 days were reviewed and compared.

RESULTS

Thirty-nine rLFs were matched to 39 fLF procedures. No significant differences were observed in clinical outcomes. rLF had higher total encounter costs (P < 0.001) and day-of-surgery costs (P = 0.005). Increased costs were mostly because of increased supply cost (0.0183) and operating room time cost (P < 0.001). Linear regression showed a positive relationship with operating room time and cost in rLF (P < 0.001).

CONCLUSION

rLF is associated with a higher index surgery cost. The main factor driving increased cost is supply costs, with other variables too small in difference to make a notable financial effect. rLF will become more common, and other institutions may need to take a closer financial look at this more novel instrumentation before adoption.

Robot-Assisted Thoracolumbar Fixation After Acute Spinal Trauma: A Case Series

BACKGROUND

Pedicle screw fixation has become the workhorse for the stabilization of the thoracolumbar spine. Since accurate pedicle screw placement is necessary for a successful surgery, three-dimensional navigation has become a mainstay for placing pedicle screws. However, the published studies have an overrepresentation of lumbar screws despite the prevalence of thoracic fractures. Furthermore, no robotic-assisted pedicle screw study has focused solely on traumatic fractures. The goal of this study was to address whether (1) robot-assisted pedicle screw placement had comparable accuracy in the thoracic and thoracolumbar region and (2) robot-assisted spine surgery was feasible in an acute, traumatic setting.

METHODS

We performed 14 consecutive, thoracolumbar spinal stabilization procedures in which 126 pedicle screws were placed using the Globus ExcelsiusGPS® spine robot in an acute, traumatic setting. Operative times were measured, and the accuracy of pedicle screws was assessed with the Gertzbein and Robbins classification system by two board-certified neuroradiologists.

RESULTS

A total of 60-thoracic (T3-T11), the 24-thoracolumbar junction (T12-L1), 40-lumbar (L2-L5), and two-sacral pedicle screws were placed. Pedicle screw placement was accurate with a < 1% (1/126) pedicle breach rate. Thoracolumbar robotic spine surgery in an acute, traumatic setting was demonstrated to have a good safety profile with only one minor neurological deficit which was related to positioning. Furthermore, surgical times were inversely related to the case number.

CONCLUSIONS

These results together suggest that robot-assisted spine surgery is accurate in the thoracic spine. Furthermore, placement of thoracolumbar screws in an acute trauma is non-inferior to other methods when based on accuracy.

Percutaneous thoraco-lumbar-sacral pedicle screw placement accuracy results from a multi-center, prospective clinical study using a skin marker-based optical navigation system

STUDY DESIGN

Prospective multi-center study.

OBJECTIVE

The study aimed to evaluate the accuracy of pedicle screw placement using a skin marker-based optical surgical navigation system for minimal invasive thoraco-lumbar-sacral pedicle screw placement.

METHODS

The study was performed in a hybrid Operating Room with a video camera-based navigation system integrated in the imaging hardware. The patient was tracked with non-invasive skin markers while the instrument tracking was via an on-shaft optical marker pattern. The screw placement accuracy assessment was performed by three independent reviewers, using the Gertzbein grading. The screw placement time as well as the staff and patient radiation doses was also measured.

RESULTS

In total, 211 screws in 39 patients were analyzed for screw placement accuracy. Of these 32.7% were in the thoracic region, 59.7% were in the lumbar region, and 7.6% were in the sacral region. An overall accuracy of 98.1% was achieved. No screws were deemed severely misplaced (Gertzbein grading 3). The average time for screw placement was 6 min and 25 secs (± 3 min 33 secs). The average operator radiation dose per subject was 40.3 µSv. The mean patient effective dose (ED) was 11.94 mSv.

CONCLUSION

Skin marker-based ON can be used to achieve very accurate thoracolumbarsacral pedicle screw placements.

Development of a Robotic Spine Surgery Program: Rationale, Strategy, Challenges, and Monitoring of Outcomes After Implementation

Surgical robots were invented in the 1980s, and since then, robotic-assisted surgery has become commonplace. In the field of spine surgery, robotic assistance is utilized mainly to place pedicle screws, and multiple studies have demonstrated that robots can increase the accuracy of screw placement and reduce radiation exposure to the patient and the surgeon. However, this may be at the cost of longer operative times, complications, and the risk of errors in mapping the patient's anatomy.

Robot Versus Fluoroscopy-Assisted Vertebroplasty and Kyphoplasty for Osteoporotic Vertebral Compression Fractures: A Systematic Review and Meta-analysis

OBJECTIVE

This study aimed to conduct a systematic review and meta-analysis to compare the clinical results and complications of robot-assisted (RA) versus fluoroscopy-assisted (FA) percutaneous vertebral augmentation (PVA) in the treatment of osteoporotic vertebral compression fractures (OVCFs).

METHODS

A comprehensive search of online databases including PubMed, Embase, Cochrane Library, web of science, and core journals of China National Knowledge Infrastructure were performed to identify related studies reporting the clinical results and complications of RA versus FA-assisted PVA in the treatment of OVCFs. The rate of bone cement leakage was used to assess the complications. After the surgery, the clinical findings were analyzed using the Visual Analog Scale scores and the Oswestry Disability Index scores. The surgical time, intraoperative fluoroscopy frequency, and x-ray exposure duration were used to evaluate the perioperative results. Forest plots were constructed to investigate the results.

RESULTS

RA-PVA had a significantly lower bone cement leakage rate, shorter fluoroscopy frequency, and shorter radiation exposure time of doctors compared with FA-PVA. However, no significant differences were found between RA-PVA and FA-PVA in operative time and radiation exposure time of patients. Furthermore, no statistically differences were found between the 2 groups in Visual Analog Scale and Oswestry Disability Index scores after surgery.

CONCLUSIONS

This meta-analysis showed that RA-PVA can reduce bone cement leakage rate, fluoroscopy frequency, and doctors' radiation exposure time. With the advancement of RA technology, we anticipate more high-quality randomized controlled trials of RA versus FA-PVA in the future to validate and update the results of this analysis.

Robotics Reduces Radiation Exposure in Minimally Invasive Lumbar Fusion Compared With Navigation

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

To compare robotics and navigation for minimally invasive elective lumbar fusion in terms of radiation exposure and time demand.

SUMMARY OF BACKGROUND DATA

Although various studies have been conducted to demonstrate the benefits of both navigation and robotics over fluoroscopy in terms of radiation exposure, literature is lacking in studies comparing robotics versus navigation.

MATERIALS AND METHODS

Patients who underwent elective one-level or two-level minimally invasive transforaminal lumbar interbody fusion (TLIF) by a single surgeon using navigation (Stryker SpineMask) or robotics (ExcelsiusGPS) were included (navigation 2017-2019, robotics 2019-2021, resulting in prospective cohorts of consecutive patients for each modality). All surgeries had the intraoperative computed tomography workflow. The two cohorts were compared for radiation exposure [fluoroscopy time and radiation dose: image capture, surgical procedure, and overall) and time demand (time for setup and image capture, operative time, and total operating room (OR) time].

RESULTS

A total of 244 patients (robotics 111, navigation 133) were included. The two cohorts were similar in terms of baseline demographics, primary/revision surgeries, and fusion levels. For one-level TLIF, total fluoroscopy time, total radiation dose, and % of radiation for surgical procedure were significantly less with robotics compared with navigation (20 vs. 25 s, P <0.001; 38 vs. 42 mGy, P =0.05; 58% vs. 65%, P =0.021). Although time for setup and image capture was significantly less with robotics (22 vs. 25 min, P <0.001) and operative time was significantly greater with robotics (103 vs. 93 min, P <0.001), there was no significant difference in the total OR time (145 vs. 141 min, P =0.25). Similar findings were seen for two-level TLIF as well.

CONCLUSION

Robotics for minimally invasive TLIF, compared with navigation, leads to a significant reduction in radiation exposure both to the surgeon and patient, with no significant difference in the total OR time.

The Future of Minimally Invasive Spinal Surgery

Strong forces are pushing minimally invasive spinal surgery (MISS) to the forefront of spine care. Less-invasive surgical techniques have been enabled by a variety of technical advances. Despite the promise of MISS, however, several factors, including few training opportunities, perception of a steep learning curve, and high upfront costs, have limited the adoption of these techniques. The "6 T's" is a framework highlighting key factors that must be accounted for to ensure safe and effective MISS as techniques continually evolve. Further, technological advancement in endoscopy, robotics, and augmented/virtual reality is enhancing minimally invasive surgeries to make them even less invasive and safer for patients. The evolution of these new techniques and technologies is driving the future of MISS.

The XVS System During Open Spinal Fixation Procedures in Patients Requiring Pedicle Screw Placement in the Lumbosacral Spine

OBJECTIVE

This pilot study was undertaken to evaluate the safety, performance, and usability of the Xvision-Spine (XVS) System (Augmedics, Arlington Heights, IL) during open spinal fixation procedures in patients requiring pedicle screw placement in the lumbosacral spine.

METHODS

The XVS System is an augmented reality head-mounted display (HMD) based on a computer navigation system designed to assist surgeons in accurately placing pedicle screws. It uses an HMD-mounted tracking camera to provide optical tracking technology, and provides the surgeon a translucent direct near-eye display of the navigated surgical instrument's location relative to the computed tomographic image. We report the preliminary results of a prospective series of all consecutive patients who underwent augmented reality-assisted pedicle screw placement in the lumbosacral vertebrae at 3 institutions. Clinical accuracy for each pedicle screw was graded with Gertzbein-Robbins scores by 2 independent and blinded neuroradiologists.

RESULTS

The 19 study participants included 8 men and 11 women with a mean age of 59.13 ± 12.09 and 59.91 ± 12.89 years, respectively. Seventeen procedures were successfully completed via the XVS System. Two procedures were not completed due to technical issues with the system's intraoperative scanner. A total of 86 screws were inserted. The accuracy of the XVS System was 97.7%.

CONCLUSIONS

The XVS System's performance in accurate placement of pedicle screws in the lumbosacral vertebrae had an overall accuracy of 97.7%. These preliminary results were comparable to the accuracy of other manual computer-assisted navigation systems reported in the literature.

Comparison of Accuracy and Clinical Outcomes of Robot-Assisted Versus Fluoroscopy-Guided Pedicle Screw Placement in Posterior Cervical Surgery

STUDY DESIGN

This was a prospective controlled study.

OBJECTIVE

To compare the accuracy and clinical outcomes of robot-assisted (RA) and fluoroscopy-guided (FG) pedicle screw placement in posterior cervical surgery.

METHODS

This study included 58 patients. The primary outcome measures were the 1-time success rate and the accuracy of pedicle screw placement according to the Gertzbein-Robbins scales. The secondary outcome measures, including the operative time, intraoperative blood loss, hospital stay, cumulative radiation time, radiation dose, intraoperative advent events, and postoperative complications, were recorded and analyzed. The Japanese Orthopedics Association (JOA) scores and Neck Disability Index (NDI) were used to assess the neurological function of patients before and at 3 and 6 months after surgery.

RESULTS

The rate of grade A was significantly higher in the RA group than in the FG group (90.6% and 71.1%; P < .001). The clinically acceptable accuracy was 97.2% in the RA group and 90.7% in the FG group (P = .009). Moreover, the 1-time success rate was significantly higher in the RA group than in the FG group. The RA group had less radiation time (P < .001) and less radiation dose (P = .002) but longer operative time (P = .001). There were no significant differences in terms of intraoperative blood loss, hospital stay, intraoperative adverse events, postoperative complications, JOA scores, and NDI scores at each follow-up time point between the 2 groups.

CONCLUSIONS

The RA technique achieved higher accuracy and 1-time success rate of pedicle screw placement in posterior cervical surgery while achieving comparable clinical outcomes.

When giants talk; robotic dialog during thoracolumbar and sacral surgery

Background

Spinal trauma patients treated in a specialized hybrid operating room (OR) using two robotic systems communicating during surgery.

Methods

Retrospective review of patients with thoracolumbar or sacral fractures who underwent surgical fixation between Jan 2017 to Jan 2020 with robotic-guided percutaneous pedicle screw insertion in the specialized hybrid OR with Robotic flat panel 3D C-arm (ArtisZeego) for intraoperative interventional imaging connected with the robotic-guidance platform Renaissance (Mazor Robotics).

Results

Twenty eight surgeries were performed in 27 patients; 23 with traumatic spinal fractures, 4 with multi-level thoracolumbar compression fractures due to severe osteoporosis. Average patient age 49 (range 12–86). Average radiation exposure time 40 s (range 12–114 s). Average radiation exposure dose 11,584 ± SD uGym² (range 4454–58,959). Lumber levels operated on were between T5 and S2 (shortest three vertebras and longest eight vertebras). 235 (range 5–11) trajectories were performed. All trajectories were accurate in all cases percutaneous pedicle screws placement was correct, without breach noted at the pedicle in any of the cases. No major complications reported. In all cases, follow-up X-rays showed adequate fracture reduction with restoration.

Conclusions

Merging of surgical robotics technologies increases patient safety and surgeon and patient confidence in percutaneous spine traumatic procedures.

Bone-Mounted Robotic System in Minimally Invasive Spinal Surgery for Osteoporosis Patients: Clinical and Radiological Outcomes

Purpose

Severe complications, including screw loosening events and low fusion rates, in spinal fusion surgery using the traditional open method are problematic. This retrospective study aimed to evaluate the rate of screw loosening and the clinical outcomes of bone-mounted miniature robot-assisted pedicle screw placement in patients treated for degenerative spinal disease.

Patients and Methods

Data were collected from the medical records of 118 patients (mean age, 69 years). Differences in clinical outcomes, including the Oswestry disability index, visual analog scale score, screw loosening rate, cage fusion rate, and complications, were evaluated among different bone mineral densities.

Results

The screw loosening and cage fusion rates for all patients, normal bone mineral density, osteopenia, and osteoporosis groups were 12%, 8.6%, 13.1%, and 14%, respectively, and 85.3%, 93%, 82.5%, and 81.4%, respectively. There was a higher screw loosening rate and a lower cage fusion rate in the osteopenia and osteoporosis groups than in the normal bone density group. The accuracy of the screw placement was 97.3%. There were no statistically significant differences in the Oswestry disability index and visual analog scale scores, and no major complications for dural tear or vascular or visceral injury.

Conclusion

Our study demonstrated an acceptable screw loosening rate in patients with osteoporosis compared to that in patients with normal bone mineral density. The robotic system resulted in accurate screw placement in patients with osteoporosis.

Comparative Analysis of Optoelectronic Accuracy in the Laboratory Setting Versus Clinical Operative Environment: A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVES

The optoelectronic camera source and data interpolation process serve as the foundation for navigational integrity in robotic-assisted surgical platforms. The current systematic review serves to provide a basis for the numerical disparity observed when comparing the intrinsic accuracy of optoelectronic cameras versus accuracy in the laboratory setting and clinical operative environments.

METHODS

Review of the PubMed and Cochrane Library research databases was performed. The exhaustive literature compilation obtained was then vetted to reduce redundancies and categorized into topics of intrinsic accuracy, registration accuracy, musculoskeletal kinematic platforms, and clinical operative platforms.

RESULTS

A total of 465 references were vetted and 137 comprise the basis for the current analysis. Regardless of application, the common denominators affecting overall optoelectronic accuracy are intrinsic accuracy, registration accuracy, and application accuracy. Intrinsic accuracy equaled or was less than 0.1 mm translation and 0.1 degrees rotation per fiducial. Controlled laboratory platforms reported 0.1 to 0.5 mm translation and 0.1 to 1.0 degrees rotation per array. Accuracy in robotic-assisted spinal surgery reported 1.5 to 6.0 mm translation and 1.5 to 5.0 degrees rotation when comparing planned to final implant position.

CONCLUSIONS

Navigational integrity and maintenance of fidelity of optoelectronic data is the cornerstone of robotic-assisted spinal surgery. Transitioning from controlled laboratory to clinical operative environments requires an increased number of steps in the optoelectronic kinematic chain and error potential. Diligence in planning, fiducial positioning, system registration and intra-operative workflow have the potential to improve accuracy and decrease disparity between planned and final implant position.

Computed Tomography-Based Navigation System in Current Spine Surgery: A Narrative Review

The number of spine surgeries using instrumentation has been increasing with recent advances in surgical techniques and spinal implants. Navigation systems have been attracting attention since the 1990s in order to perform spine surgeries safely and effectively, and they enable us to perform complex spine surgeries that have been difficult to perform in the past. Navigation systems are also contributing to the improvement of minimally invasive spine stabilization (MISt) surgery, which is becoming popular due to aging populations. Conventional navigation systems were based on reconstructions obtained by preoperative computed tomography (CT) images and did not always accurately reproduce the intraoperative patient positioning, which could lead to problems involving inaccurate positional information and time loss associated with registration. Since 2006, an intraoperative CT-based navigation system has been introduced as a solution to these problems, and it is now becoming the mainstay of navigated spine surgery. Here, we highlighted the use of intraoperative CT-based navigation systems in current spine surgery, as well as future issues and prospects.

A tale of two robots: Operating times and learning curves in robot-assisted lumbar fusion

Robotic assistance technologies are being incorporated into minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) to minimize radiation exposure to the patient and operating staff. However, they introduce new issues including increased operating time and difficult incorporation into surgical workflow. This study, conducted with 42 patients under the care of one neurosurgeon in Sydney, Australia, investigates the operating time increase with three different robotic modalities, and the learning curves they pose to the surgeon. Between the comparable modalities of freehand MIS-TLIF and Mazor Renaissance® CT to Fluoro, there was a significant increase in time from patient draping to insertion of the final K-wire (p = 0.0019), and a non-significant increase in time per K-wire (p = 0.55) using Mazor Renaissance®. Comparing the ROSA® and Mazor Renaissance® Scan and Plan, there were significant increases in drape to final K-wire time and time per K-wire using ROSA® assistance (p = 0.000068 and p = 0.011). ROSA® also had a steeper learning curve compared to both Mazor Renaissance® modalities, which were similar. Our study shows that Mazor Renaissance® modalities are superior to ROSA® in minimizing extra operating time, and also have easier learning curves; however, both modalities increase operating time compared with freehand MIS-TLIF. This study, to our knowledge, is the first to compare multiple robotic techniques in MIS-TLIF. Though these results highlight important differences between robotic modalities that are crucial for spinal surgeons to understand, the low sample size and variability in data reveal the need for larger, multi-centre studies in this field.

CT-to-fluoroscopy registration versus scan-and-plan registration for robot-assisted insertion of lumbar pedicle screws

OBJECTIVE

Pedicle screw insertion for stabilization after lumbar fusion surgery is commonly performed by spine surgeons. With the advent of navigation technology, the accuracy of pedicle screw insertion has increased. Robotic guidance has revolutionized the placement of pedicle screws with 2 distinct radiographic registration methods, the scan-and-plan method and CT-to-fluoroscopy method. In this study, the authors aimed to compare the accuracy and safety of these methods.

METHODS

A retrospective chart review was conducted at 2 centers to obtain operative data for consecutive patients who underwent robot-assisted lumbar pedicle screw placement. The newest robotic platform (Mazor X Robotic System) was used in all cases. One center used the scan-and-plan registration method, and the other used CT-to-fluoroscopy for registration. Screw accuracy was determined by applying the Gertzbein-Robbins scale. Fluoroscopic exposure times were collected from radiology reports.

RESULTS

Overall, 268 patients underwent pedicle screw insertion, 126 patients with scan-and-plan registration and 142 with CT-to-fluoroscopy registration. In the scan-and-plan cohort, 450 screws were inserted across 266 spinal levels (mean 1.7 ± 1.1 screws/level), with 446 (99.1%) screws classified as Gertzbein-Robbins grade A (within the pedicle) and 4 (0.9%) as grade B (< 2-mm deviation). In the CT-to-fluoroscopy cohort, 574 screws were inserted across 280 lumbar spinal levels (mean 2.05 ± 1.7 screws/ level), with 563 (98.1%) grade A screws and 11 (1.9%) grade B (p = 0.17). The scan-and-plan cohort had nonsignificantly less fluoroscopic exposure per screw than the CT-to-fluoroscopy cohort (12 ± 13 seconds vs 11.1 ± 7 seconds, p = 0.3).

CONCLUSIONS

Both scan-and-plan registration and CT-to-fluoroscopy registration methods were safe, accurate, and had similar fluoroscopy time exposure overall.

Does robot-assisted navigation influence pedicle screw selection and accuracy in minimally invasive spine surgery?

OBJECTIVE

The accuracy of percutaneous pedicle screw placement has increased with the advent of robotic and surgical navigation technologies. However, the effect of robotic intraoperative screw size and trajectory templating remains unclear. The purpose of this study was to compare pedicle screw sizes and accuracy of placement using robotic navigation (RN) versus skin-based intraoperative navigation (ION) alone in minimally invasive lumbar fusion procedures.

METHODS

A retrospective cohort study was conducted using a single-institution registry of spine procedures performed over a 4-year period. Patients who underwent 1- or 2-level primary or revision minimally invasive surgery (MIS)–transforaminal lumbar interbody fusion (TLIF) with pedicle screw placement, via either robotic assistance or surgical navigation alone, were included. Demographic, surgical, and radiographic data were collected. Pedicle screw type, quantity, length, diameter, and the presence of endplate breach or facet joint violation were assessed. Statistical analysis using the Student t-test and chi-square test was performed to evaluate the differences in pedicle screw sizes and the accuracy of placement between both groups.

RESULTS

Overall, 222 patients were included, of whom 92 underwent RN and 130 underwent ION MIS-TLIF. A total of 403 and 534 pedicle screws were placed with RN and ION, respectively. The mean screw diameters were 7.25 ± 0.81 mm and 6.72 ± 0.49 mm (p < 0.001) for the RN and ION groups, respectively. The mean screw length was 48.4 ± 4.48 mm in the RN group and 45.6 ± 3.46 mm in the ION group (p < 0.001). The rates of “ideal” pedicle screws in the RN and ION groups were comparable at 88.5% and 88.4% (p = 0.969), respectively. The overall screw placement was also similar. The RN cohort had 63.7% screws rated as good and 31.4% as acceptable, while 66.1% of ION-placed screws had good placement and 28.7% had acceptable placement (p = 0.661 and p = 0.595, respectively). There was a significant reduction in high-grade breaches in the RN group (0%, n = 0) compared with the ION group (1.2%, n = 17, p = 0.05).

CONCLUSIONS

The results of this study suggest that robotic assistance allows for placement of screws with greater screw diameter and length compared with surgical navigation alone, although with similarly high accuracy. These findings have implied that robotic platforms may allow for safe placement of the “optimal screw,” maximizing construct stability and, thus, the ability to obtain a successful fusion.

Initial Intraoperative Experience with Robotic-Assisted Pedicle Screw Placement with Cirq® Robotic Alignment: An Evaluation of the First 70 Screws

BACKGROUND

Robot-guided spine surgery is based on a preoperatively planned trajectory that is reproduced in the operating room by the robotic device. This study presents our initial experience with thoracolumbar pedicle screw placement using Brainlab's Cirq^® surgeon-controlled robotic arm (BrainLab, Munich, Germany).

METHODS

All patients who underwent robotic-assisted implantation of pedicle screws in the thoracolumbar spine were included in the study. Our workflow, consisting of preoperative imagining, screw planning, intraoperative imaging with automatic registration, fusion of the preoperative and intraoperative imaging with a review of the preplanned screw trajectories, robotic-assisted insertion of K-wires, followed by a fluoroscopy-assisted insertion of pedicle screws and control iCT scan, is described.

RESULTS

A total of 12 patients (5 male and 7 females, mean age 67.4 years) underwent 13 surgeries using the Cirq^® Robotic Alignment Module for thoracolumbar pedicle screw implantation. Spondylodiscitis, metastases, osteoporotic fracture, and spinal canal stenosis were detected. A total of 70 screws were implanted. The mean time per screw was 08:27 ± 06:54 min. The mean time per screw for the first 7 surgeries (first 36 screws) was 16:03 ± 09:32 min and for the latter 6 surgeries (34 screws) the mean time per screw was 04:35 ± 02:11 min (p < 0.05). Mean entry point deviation was 1.9 ± 1.23 mm, mean deviation from the tip of the screw was 2.61 ± 1.6 mm and mean angular deviation was 3.5° ± 2°. For screw-placement accuracy we used the CT-based Gertzbein and Robbins System (GRS). Of the total screws, 65 screws were GRS A screws (92.85%), one screw was a GRS B screw, and two further screws were grade C. Two screws were D screws (2.85%) and underwent intraoperative revision. There were no perioperative deficits.

CONCLUSION

Brainlab's Cirq^® Robotic Alignment surgeon-controlled robotic arm is a safe and beneficial method for accurate thoracolumbar pedicle screw placement with high accuracy.

Robotic navigation in spine surgery: Where are we now and where are we going?

Robotic navigation is a new and rapidly emerging niche within minimally invasive spine surgery. The robotic arms-race began in 2004 and has resulted in no less than four major robotic surgical adjuncts. Current Food and Drug Administration (FDA)-approved applications of robotic navigation are limited to pedicle screw instrumentation, but new indications and experimental applications are rapidly emerging. As with any new technology, robotic navigation must be vetted for clinical efficacy, efficiency, safety, and cost-effectiveness. Given the rapid advancements made on a yearly basis, it is important to make frequent and objective assessments of the available technology. Thus, the authors seek to provide the most up-to-date review of the history, currently available technology, learning curve, novel applications, and cost effectiveness of today's available robotic systems as it relates to spine surgery.

Complications and Revision Rates in Minimally Invasive Robotic-Guided Versus Fluoroscopic-Guided Spinal Fusions: The MIS ReFRESH Prospective Comparative Study

STUDY DESIGN

Prospective, multicenter, partially randomized.

OBJECTIVE

Assess rates of complications, revision surgery, and radiation between Mazor robotic-guidance (RG) and fluoro-guidance (FG).

SUMMARY OF BACKGROUND DATA

Minimally invasive surgery MIS ReFRESH is the first study designed to compare RG and FG techniques in adult minimally invasive surgery (MIS) lumbar fusions.

METHODS

Primary endpoints were analyzed at 1 year follow-up. Analysis of variables through Cox logistic regression and a Kaplan-Meier Survival Curve of surgical complications.

RESULTS

Nine sites enrolled 485 patients: 374 (RG arm) and 111 (FG arm). 93.2% of patients had more than 1 year f/u. There were no differences for sex, Charlson Comorbidity Index, diabetes, or tumor. Mean age of RG patients was 59.0 versus 62.5 for FG (P = 0.009) and body mass index (BMI) was 31.2 versus 28.1 (P< 0.001). Percentage of smokers was almost double in the RG (15.2% vs. 7.2%, P = 0.029). Surgical time was similar (skin-to-skin time/no. of screws) at 24.9 minutes RG and 22.9 FG (P = 0.550). Fluoroscopy during surgery/no. of screws was 15.5 seconds RG versus 35.4 seconds FG, (15 seconds average reduction). Fluoroscopy time during instrumentation/no. of screws was 3.6 seconds RG versus 17.8 seconds FG showing an 80% average reduction of fluoro time/screw in RG (P < 0.001). Within 1 year follow-up, there were 39 (10.4%) surgical complications RG versus 39 (35.1%) FG, and 8 (2.1%) revisions RG versus 7 (6.3%) FG. Cox regression analysis including age, sex, BMI, CCI, and no. of screws, demonstrated that the hazard ratio (HR) for complication was 5.8 times higher FG versus RG (95% CI: 3.5-9.6, P < 0.001). HR for revision surgery was 11.0 times higher FG versus RG cases (95% CI 2.9-41.2, P < 0.001).

CONCLUSION

Mazor robotic-guidance was found to have a 5.8 times lower risk of a surgical complication and 11.0 times lower risk for revision surgery. Surgical time was similar between groups and robotic-guidance reduced fluoro time per screw by 80% (approximately 1 min/case).Level of Evidence: 2.

The Clinical Impact of Image Guidance and Robotics in Spinal Surgery: A Review of Safety, Accuracy, Efficiency, and Complication Reduction

Image guidance (IG) and robotic-assisted (RA) surgery are modern technological advancements that have provided novel ways to perform precise and accurate spinal surgery. These innovations supply real-time, three-dimensional imaging information to aid in instrumentation, decompression, and implant placement. Although nothing can replace the knowledge and expertise of an experienced spine surgeon, these platforms do have the potential to supplement the individual surgeon's capabilities. Specific advantages include more precise pedicle screw placement, minimally invasive surgery with less reliance on intraoperative fluoroscopy, and lower radiation exposure to the surgeon and staff. As these technologies have become more widely adopted over the years, novel uses such as tumor resection have been explored. Disadvantages include the cost of implementing IG and robotics platforms, the initial learning curve for both the surgeon and the staff, and increased patient radiation exposure in scoliosis surgery. Also, given the relatively recent transition of many procedures from inpatient settings to ambulatory surgery centers, access to current devices may be cost prohibitive and not as readily available at some centers. Regarding patient-related outcomes, much further research is warranted. The short-term benefits of minimally invasive surgery often bolster the perioperative and early postoperative outcomes in many retrospective studies on IG and RA surgery. Randomized controlled trials limiting such confounding factors are warranted to definitively show potential independent improvements in patient-related outcomes specifically attributable to IG and RA alone. Nonetheless, irrespective of these current unknowns, it is clear that these technologies have changed the field and the practice of spine surgery. Surgeons should be familiar with the potential benefits and tradeoffs of these platforms when considering adopting IG and robotics in their practices.

Less Invasive Pediatric Spinal Deformity Surgery: The Case for Robotic-Assisted Placement of Pedicle Screws

Introduction: Pediatric spinal deformity involves a complex 3-dimensional (3D) deformity that increases the risk of pedicle screw placement due to the close proximity of neurovascular structures. To increase screw accuracy, improve patient safety, and minimize surgical complications, the placement of pedicle screws is evolving from freehand techniques to computer-assisted navigation and to the introduction of robotic-assisted placement. Purpose: The aim of this review was to review the current literature on the use of robotic navigation in pediatric spinal deformity surgery to provide both an error analysis of these techniques and to provide recommendations to ensure its safe application. Methods: A narrative review was conducted in April 2021 using the MEDLINE (PubMed) database. Studies were included if they were peer-reviewed retrospective or prospective studies, included pediatric patients, included a primary diagnosis of pediatric spine deformity, utilized robotic-assisted spinal surgery techniques, and reported thoracic or lumbar pedicle screw breach rates or pedicle screw malpositioning. Results: In the few studies published on the use of robotic techniques in pediatric spinal deformity surgery, several found associations between the technology and increased rates of screw placement accuracy, reduced rates of breach, and minimal complications. All were retrospective studies. Conclusions: Current literature is of a low level of evidence; nonetheless, the findings suggest the accuracy and safety of robotic-assisted spinal surgery in pediatric pedicle screw placement. The introduction of robotics may drive further advances in less invasive pediatric spinal deformity surgery. Further study is warranted.

Application and Evaluation of an Independent Robotic Arm System in K-wire Placement for Lumbar Fusion

STUDY DESIGN

A single-center randomized controlled study.

OBJECTIVE

The objective of this study was to introduce a novel robotic system with an independent arm ("Orthbot Intelligent Orthopedic Minimally Invasive System"; Xin Junte Surgical Technologies) that has been developed and tested as a surgical assistant for autoplacement of the Kirschner wire (K-wire) in lumbar fusion, and to evaluate its accuracy by comparing it with the conventional free-hand instrumentation.

SUMMARY OF BACKGROUND DATA

Robotic technology has performed excellently in spine surgeries and has demonstrated high clinical value and potential. Robot-assisted spinal surgery is now being promoted as a paradigm for technology-led advancement.

MATERIALS AND METHODS

A total of 24 patients were recruited and assigned randomly to the robotic arm group (RG) or the free-hand group (FG). Deviation distance and deviation angle (DA) of K-wire placement were measured and compared between the RG and the FG.

RESULTS

The average deviation distance was 0.88±0.08 mm in the RG and 5.13±1.68 mm in the FG (P<0.001). In both coronal and sagittal radiographs, the average DA of K-wire placement was smaller in the RG (P<0.05), and in both axial and sagittal computed tomography scans, the average DA of pedicle screw placement was also lower in the RG (P<0.05), which indicated higher accuracy of the robotic system.

CONCLUSIONS

The novel robotic system in this study has shown certain advantages over the conventional free-hand approach in K-wire placement for lumbar fusion, including being more accurate in K-wire placement, fully automatic, and more adaptive to preoperative plans. Although the robotic arm proves to be promising in our results, the small sample size in this clinical study necessitates further multicenter, large sample follow-up studies to verify its advantages.

Accuracy of Robotic-Assisted Spinal Surgery-Comparison to TJR Robotics, da Vinci Robotics, and Optoelectronic Laboratory Robotics

BACKGROUND

The optoelectronic camera source and data interpolation serve as the foundation for navigational integrity in the robotic-assisted surgical platform. The objective of the current systematic review serves to provide a basis for the numerical disparity that exists when comparing the intrinsic accuracy of optoelectronic cameras: accuracy observed in the laboratory setting versus accuracy in the clinical operative environment. It is postulated that there exists a greater number of connections in the optoelectronic kinematic chain when analyzing the clinical operative environment to the laboratory setting. This increase in data interpolation, coupled with intraoperative workflow challenges, reduces the degree of accuracy based on surgical application and to that observed in controlled musculoskeletal kinematic laboratory investigations.

METHODS

Review of the PubMed and Cochrane Library research databases was performed. The exhaustive literature compilation obtained was then vetted to reduce redundancies and categorized into topics of intrinsic optoelectronic accuracy, registration accuracy, musculoskeletal kinematic platforms, and clinical operative platforms.

RESULTS

A total of 147 references make up the basis for the current analysis. Regardless of application, the common denominators affecting overall optoelectronic accuracy are intrinsic accuracy, registration accuracy, and application accuracy. Intrinsic accuracy of optoelectronic tracking equaled or was less than 0.1 mm of translation and 0.1° of rotation per fiducial. Controlled laboratory platforms reported 0.1 to 0.5 mm of translation and 0.1°-1.0° of rotation per array. There is a huge falloff in clinical applications: accuracy in robotic-assisted spinal surgery reported 1.5 to 6.0 mm of translation and 1.5° to 5.0° of rotation when comparing planned to final implant position. Total Joint Robotics and da Vinci urologic robotics computed accuracy, as predicted, lies between these two extremes-1.02 mm for da Vinci and 2 mm for MAKO.

CONCLUSIONS

Navigational integrity and maintenance of fidelity of optoelectronic data is the cornerstone of robotic-assisted spinal surgery. Transitioning from controlled laboratory to clinical operative environments requires an increased number of steps in the optoelectronic kinematic chain and error potential. Diligence in planning, fiducial positioning, system registration, and intraoperative workflow have the potential to improve accuracy and decrease disparity between planned and final implant position. The key determining factors limiting navigation resolution accuracy are highlighted by this Cochrane research analysis.

Overview of Robotic Technology in Spine Surgery

As robotics in spine surgery has progressed over the past 2 decades, studies have shown mixed results on its clinical outcomes and economic impact. In this review, we highlight the evolution of robotic technology over the past 30 years, discussing early limitations and failures. We provide an overview of the history and evolution of currently available spinal robotic platforms and compare and contrast the available features of each. We conclude by summarizing the literature on robotic instrumentation accuracy in pedicle screw placement and clinical outcomes such as complication rates and briefly discuss the future of robotic spine surgery.

Is there a difference between navigated and non-navigated robot cohorts in robot-assisted spine surgery? A multicenter, propensity-matched analysis of 2,800 screws and 372 patients

BACKGROUND CONTEXT

Robot-assisted spine surgery continues to rapidly develop as evidenced by the growing literature in recent years. In addition to demonstrating excellent pedicle screw accuracy, early studies have explored the impact of robot-assisted spine surgery on reducing radiation time, length of hospital stay, operative time, and perioperative complications in comparison to conventional freehand technique. Recently, the Mazor X Stealth Edition was introduced in 2018. This robotic system integrates Medtronic's Stealth navigation technology into the Mazor X platform, which was introduced in 2016. It is unclear what the impact of these advancements have made on clinical outcomes.

PURPOSE

To compare the outcomes and complications between the most recent iterations of the Mazor Robot systems: Mazor X and Mazor X Stealth Edition.

STUDY DESIGN

Multicenter cohort PATIENT SAMPLE: Among four different institutions, we included adult (≥18 years old) patients who underwent robot-assisted spine surgery with either the Mazor X (non-navigated robot) or Stealth (navigated robot) platforms.

OUTCOME MEASURES

Primary outcomes included robot time per screw, fluoroscopic radiation time, screw accuracy, robot abandonment, and clinical outcomes with a minimum 90 day follow up.

METHODS

A one-to-one propensity-score matching algorithm based on perioperative factors (e.g. demographics, comorbidities, primary diagnosis, open vs. percutaneous instrumentation, prior spine surgery, instrumented levels, pelvic fixation, interbody fusion, number of planned robot screws) was employed to control for the potential selection bias between the two robotic systems. Chi-square/fisher exact test and t-test/ANOVA were used for categorical and continuous variables, respectively.

RESULTS

From a total of 646 patients, a total of 372 adult patients were included in this study (X: 186, Stealth: 186) after propensity score matching. The mean number of instrumented levels was 4.3. The mean number of planned robot screws was 7.8. Similar total operative time and robot time per screw occurred between cohorts (p>0.05). However, Stealth achieved significantly shorter fluoroscopic radiation time per screw (Stealth: 7.2 seconds vs. X: 10.4 seconds, p<.001) than X. The screw accuracy for both robots was excellent (Stealth: 99.6% vs. X: 99.1%, p=0.120). In addition, Stealth achieved a significantly lower robot abandonment rate (Stealth: 0% vs. X: 2.2%, p=0.044). Furthermore, a lower blood transfusion rate was observed for Stealth than X (Stealth: 4.3% vs. X: 10.8%, p=0.018). Non-robot related complications such as dura tear, motor/sensory deficits, return to the operating room during same admission, and length of stay was similar between robots (p>0.05). The 90-day complication rates were low and similar between robot cohorts (Stealth: 5.4% vs. X: 3.8%, p=0.456).

CONCLUSION

In this multicenter study, both robot systems achieved excellent screw accuracy and low robot time per screw. However, using Stealth led to significantly less fluoroscopic radiation time, lower robot abandonment rates, and reduced blood transfusion rates than Mazor X. Other factors including length of stay, and 90-day complications were similar.

Clinical Accuracy, Technical Precision, and Workflow of the First in Human Use of an Augmented-Reality Head-Mounted Display Stereotactic Navigation System for Spine Surgery

BACKGROUND

Augmented reality mediated spine surgery is a novel technology for spine navigation. Benchmark cadaveric data have demonstrated high accuracy and precision leading to recent regulatory approval. Absence of respiratory motion in cadaveric studies may positively bias precision and accuracy results and analogous investigations are prudent in live clinical scenarios.

OBJECTIVE

To report a technical note, accuracy, precision analysis of the first in-human deployment of this technology.

METHODS

A 78-yr-old female underwent an L4-S1 decompression, pedicle screw, and rod fixation for degenerative spine disease. Six pedicle screws were inserted via AR-HMD (xvision; Augmedics, Chicago, Illinois) navigation. Intraoperative computed tomography was used for navigation registration as well as implant accuracy and precision assessment. Clinical accuracy was graded per the Gertzbein-Robbins (GS) scale by an independent neuroradiologist. Technical precision was analyzed by comparing 3-dimensional (3D) (x, y, z) virtual implant vs real implant position coordinates and reported as linear (mm) and angular (°) deviation. Present data were compared to benchmark cadaveric data.

RESULTS

Clinical accuracy (per the GS grading scale) was 100%. Technical precision analysis yielded a mean linear deviation of 2.07 mm (95% CI: 1.62-2.52 mm) and angular deviation of 2.41° (95% CI: 1.57-3.25°). In comparison to prior cadaveric data (99.1%, 2.03 ± 0.99 mm, 1.41 ± 0.61°; GS accuracy 3D linear and angular deviation, respectively), the present results were not significantly different (P > .05).

CONCLUSION

The first in human deployment of the single Food and Drug Administration approved AR-HMD stereotactic spine navigation platform demonstrated clinical accuracy and technical precision of inserted hardware comparable to previously acquired cadaveric studies.

Do robot-related complications influence 1 year reoperations and other clinical outcomes after robot-assisted lumbar arthrodesis? A multicenter assessment of 320 patients

BACKGROUND

Robot-assisted platforms in spine surgery have rapidly developed into an attractive technology for both the surgeon and patient. Although current literature is promising, more clinical data is needed. The purpose of this paper is to determine the effect of robot-related complications on clinical outcomes METHODS: This multicenter study included adult (≥18 years old) patients who underwent robot-assisted lumbar fusion surgery from 2012-2019. The minimum follow-up was 1 year after surgery. Both bivariate and multivariate analyses were performed to determine if robot-related factors were associated with reoperation within 1 year after primary surgery.

RESULTS

A total of 320 patients were included in this study. The mean (standard deviation) Charlson Comorbidity Index was 1.2 (1.2) and 52.5% of patients were female. Intraoperative robot complications occurred in 3.4% of patients and included intraoperative exchange of screw (0.9%), robot abandonment (2.5%), and return to the operating room for screw exchange (1.3%). The 1-year reoperation rate was 4.4%. Robot factors, including robot time per screw, open vs. percutaneous, and robot system, were not statistically different between those who required revision surgery and those who did not (P>0.05). Patients with robot complications were more likely to have prolonged length of hospital stay and blood transfusion, but were not at higher risk for 1-year reoperations. The most common reasons for reoperation were wound complications (2.2%) and persistent symptoms due to inadequate decompression (1.5%). In the multivariate analysis, robot related factors and complications were not independent risk factors for 1-year reoperations.

CONCLUSION

This is the largest multicenter study to focus on robot-assisted lumbar fusion outcomes. Our findings demonstrate that 1-year reoperation rates are low and do not appear to be influenced by robot-related factors and complications; however, robot-related complications may increase the risk for greater blood loss requiring a blood transfusion and longer length of stay.

Accuracy and deviation analysis of robot-assisted spinal implants: A retrospective overview of 105 cases and preliminary comparison to open freehand surgery in lumbar spondylolisthesis

BACKGROUND

Whether the accuracy of robot-assisted spinal screw placement is significantly higher than that of freehand and the source of robotic deviation remain unclear.

METHODS

Clinical data of 105 patients who underwent robot-assisted spinal surgery was collected, and screw accuracy was evaluated by computed tomography according to the modified Gertzbein-Robbins classification. Patients were grouped by percutaneous and open surgery. Intergroup comparisons of clinical and screw accuracy parameters were performed. Reasons for deviation were determined. Thirty-one patients with lumbar spondylolisthesis undergoing open robot-assisted surgery and the same number of patients treated by open freehand surgery were compared for screw accuracy.

RESULTS

Screw accuracy was not significantly different between the percutaneous and open groups in both intra- and postoperative evaluations. Tool skiving was identified as the main cause of deviation. The proportion of malpositioned screws (grade B + C + D) was significantly higher in the freehand group than in the robot-assisted group. However, remarkably malpositioned (grade C + D) screws showed no significant differences between the groups. No revision surgery was necessary.

CONCLUSIONS

Robot-assisted spinal instrumentation manifests high accuracy and low incidence of nerve injury. Tool skiving is a major cause of implant deviation.

Application of Spinal Robotic Navigation Technology to Minimally Invasive Percutaneous Treatment of Spinal Fractures: A Clinical, Non-Randomized, Controlled Study

Objective

To introduce a new robotic navigation system that assists pedicle screw implantation and verify the accuracy and stability of the system.

Methods

Pedicle screw placements were performed on the thoracic vertebrae (T)9–Lumbar vertebrae (L)5 thoracolumbar vertebrae of cadavers using robotic guidance. The operative duration, puncture success, correction, and correction time were assessed. Additionally, a total of 30 thoracolumbar fractures from September 2017 until June 2019 were included in a clinical study. Two groups were evaluated: the robotic guidance group and freehand group. Both sexes were evaluated. Mean ages were 47.0 and 49.1 years, respectively, in the robotic and freehand groups. Inclusion criteria was age >18 years and a thoracolumbar fracture. Intervention was the operative treatment of thoracolumbar fractures. Outcome parameters were the operation time, intraoperative bleeding, and fluoroscopic data. The accuracy of the pedicle screw placement and screw penetration rate of the two groups were compared using intraoperative fluoroscopic axial images.

Results

The success rate for 108 one‐time nail placements in cadavers was 88% and two‐time nail placement was 100%. Vertebral punctures at L5 took the longest to perform and achieve correction. Clinically, there were no significant differences in patients' sex, body mass index, age distribution, or intraoperative bleeding between the groups. The average X‐ray exposure time for patients and operators were 37.69 ± 9.24 s and 0 s in the robotic group (significantly lower than in the freehand group: 81.24 ± 6.97 s vs 56.29 ± 7.93 s, respectively). Success rates for one‐time screw placements were 98.64 and 88.46% in the robotic and freehand groups, respectively, which is significant. Screw penetration rates (1.36% vs 11.54%, robotic vs freehand), were significantly different.

Conclusions

The robotic system improved the accuracy and safety of pedicle screw internal fixation and reduced patients' and operators' intraoperative radiation exposure.

Robotic-Navigated Percutaneous Pedicle Screw Placement Has Less Facet Joint Violation Than Fluoroscopy-Guided Percutaneous Screws

OBJECTIVE

To directly compare robotic-versus fluoroscopy-guided percutaneous pedicle screw (PPS) placement in thoracolumbar spine trauma with a focus on clinically acceptable pedicle screw accuracy and facet joint violation (FJV).

METHODS

A retrospective chart review assessed 37 trauma patients undergoing percutaneous thoracic and/or lumbar fixation. Postoperative computed tomography images were reviewed by authors blinded to surgical technique who assessed pedicle screw trajectory accuracy and FJV frequency.

RESULTS

Seventeen patients underwent placement of 143 PPS with robotic assistance (robot group), compared with 20 patients receiving 149 PPS using fluoroscopy assistance (control group). Overall, the robot cohort demonstrated decreased FJV frequency of 2.8% versus 14.8% in controls (P = 0.0003). When further stratified by level of surgery (i.e., upper thoracic, lower thoracic, lumbar spine), the robot group had FJV frequencies of 0%, 3.2%, and 3.7%, respectively, compared with 17.7% (P = 0.0209), 14.3% (P = 0.0455), and 11.9% (P = 0.2340) in controls. The robot group had 84.6% clinically acceptable screw trajectories compared with 81.9% in controls (P = 0.6388). Within the upper thoracic, lower thoracic, and lumbar regions, the robot group had acceptable screw trajectories of 66.7%, 87.1%, and 90.7%, respectively, compared with 58.8% (P = 0.6261), 91.1% (P = 0.5655), and 97.6% (P = 0.2263) in controls.

CONCLUSIONS

There was no significant difference in clinically acceptable screw trajectory accuracy between robotic versus fluoroscopy-guided PPS placement. However, the robot cohort demonstrated a statistically significantly decreased FJV overall and specifically within the thoracic spine region. Use of robotic technology may improve radiographic outcomes for a subset of patients or spine surgeries.

Robotics in spine surgery: A systematic review

Robotic systems to assist with pedicle screw placement have recently emerged in the field of spine surgery. Here, the authors systematically reviewed the literature for evidence of these robotic systems and their utility. Thirty-four studies that reported the use of spinal instrumentation with robotic assistance and met inclusion criteria were identified. The outcome measures gathered included: pedicle screw accuracy, indications for surgery, rates of conversion to an alternative surgical method, radiation exposure, and learning curve. In our search there were five different robotic systems identified. All studies reported accuracy and the most commonly used accuracy grading scale was the Gertzbein Robbins scale (GRS). Accuracy of clinically acceptable pedicle screws, defined as < 2 mm cortical breech, ranged from 80% to 100%. Many studies categorized indications for robotic surgery with the most common being degenerative entities. Some studies reported rates of conversion from robotic assistance to manual instrumentation due to many reasons, with robotic failure as the most common. Radiation exposure data revealed a majority of studies reported less radiation using robotic systems. Studies looking at a learning curve effect with surgeon use of robotic assistance were not consistent across the literature. Robotic systems for assistance in spine surgery have continued to improve and the accuracy of pedicle screw placement remains superior when compared to free-hand technique, however rates of manual conversion are significant. Currently, these systems are successfully employed in various pathological entities where trained spine surgeons can be safe and accurate regardless of robotic training.

Robotics in Spine Surgery: A Technical Overview and Review of Key Concepts

The use of robotic systems to aid in surgical procedures has greatly increased over the past decade. Fields such as general surgery, urology, and gynecology have widely adopted robotic surgery as part of everyday practice. The use of robotic systems in the field of spine surgery has recently begun to be explored. Surgical procedures involving the spine often require fixation via pedicle screw placement, which is a task that may be augmented by the use of robotic technology. There is little margin for error with pedicle screw placement, because screw malposition may lead to serious complications, such as neurologic or vascular injury. Robotic systems must provide a degree of accuracy comparable to that of already-established methods of screw placement, including free-hand, fluoroscopically assisted, and computed tomography–assisted screw placement. In the past several years, reports have cataloged early results that show the robotic systems are associated with equivalent accuracy and decreased radiation exposure compared with other methods of screw placement. However, the literature is still lacking with regard to long-term outcomes with these systems. This report provides a technical overview of robotics in spine surgery based on experience at a single institution using the ExcelsiusGPS (Globus Medical; Audobon, PA, USA) robotic system for pedicle screw fixation. The current state of the field with regard to salient issues in robotics and future directions for robotics in spinal surgery are also discussed.