Revisions for screw malposition and clinical outcomes after robot-guided lumbar fusion for spondylolisthesis

Advancements in robotic surgery: innovations, challenges and future prospects

The use of robots has revolutionized healthcare, wherein further innovations have led to improved precision and accuracy. Conceived in the late 1960s, robot-assisted surgeries have evolved to become an integral part of various surgical specialties. Modern robotic surgical systems are equipped with highly dexterous arms and miniaturized instruments that reduce tremors and enable delicate maneuvers. Implementation of advanced materials and designs along with the integration of imaging and visualization technologies have enhanced surgical accuracy and made robots safer and more adaptable to various procedures. Further, the haptic feedback system allows surgeons to determine the consistency of the tissues they are operating upon, without physical contact, thereby preventing injuries due to the application of excess force. With the implementation of teleoperation, surgeons can now overcome geographical limitations and provide specialized healthcare remotely. The use of artificial intelligence (AI) and machine learning (ML) aids in surgical decision-making by improving the recognition of minute and complex anatomical structures. All these advancements have led to faster recovery and fewer complications in patients. However, the substantial cost of robotic systems, their maintenance, the size of the systems and proper surgeon training pose major challenges. Nevertheless, with future advancements such as AI-driven automation, nanorobots, microscopic incision surgeries, semi-automated telerobotic systems, and the impact of 5G connectivity on remote surgery, the growth curve of robotic surgery points to innovation and stands as a testament to the persistent pursuit of progress in healthcare.

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.

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 versus navigation-assisted screw placement in spinal vertebrae

PURPOSE

Both robots and navigation are effective strategies for optimizing screw placement, as compared to freehand placement. However, few studies have compared the accuracy and efficiency of these two techniques. Thus, the purpose of this study is to compare the accuracy and efficiency of robotic and navigation-assisted screw placement in the spinal vertebrae.

METHODS

The 24 spine models were divided into a robot- and navigation-assisted groups according to the left and right sides of the pedicle. The C-arm transmits image data simultaneously to the robot and navigates using only one scan. After screw placement, the accuracy of the two techniques were compared using "angular deviation" and "Gertzbein and Robbins scale" in different segments (C1-7, T1-4, T5-8, T9-12, and L1-S1). In addition, operation times were compared between robot- and navigation-assisted groups.

RESULTS

Robots and navigation systems can simultaneously assist in screw placement. The robot-assisted group had significantly less angular deviation than the navigation-assisted group from C1 to S1 (p < 0.001). At the C1-7 and T1-4 segments, the robot-assisted group had a higher rate of acceptable screws than the robot-assisted group. However, at the T5-8, T9-12, and L1-S1 segments, no significant difference was found in the incidence of acceptable screws between the two groups. Moreover, robot-assisted screw placement required less operative time than navigation (p < 0.05).

CONCLUSION

The robot is more accurate and efficient than navigation in aiding screw placement. In addition, robots and navigation can be combined without increasing the number of fluoroscopic views.

Feasibility of outpatient robot assisted minimally invasive transforaminal lumbar interbody fusion

Introduction

Lumbar interbody fusion is a common spine procedure. 199,140 elective lumbar fusions were performed in the United States in 2015. Robot assisted (RA) pedicle screw placement has advanced minimally invasive spine surgery (MIS) making short stay transforaminal lumbar interbody fusions (TLIF) with same day or next day discharge a possibility for select patients.

Methods

This study is a retrospective case series of a single surgeon's experience with RA MIS TLIF using the Globus ExcelsiusGPS system. Patients undergoing RA MIS TLIF at an outpatient surgery center between August 2020 and February 2021 were included in the study.

Results

Twenty-three patients met inclusion criteria. Ninety-six RA pedicle screws and 25 interbody cages were placed. 96/96 (100%) pedicle screws and 25/25 (100%) interbodies were found to be in satisfactory position using intraoperative x-ray. None of the instrumentation required re-placement or revision intraoperatively. 20/23 (87%) patients were able to discharge within 24 hours of the procedure. 2/23 (8.7%) patients discharged on the day of surgery. One patient of 23 (4.3%) required discharge to an inpatient rehabilitation facility post operatively. 0/23 (0%) patients required readmission for pain control.

Conclusions

Our study demonstrates the safety and feasibility of outpatient RA MIS TLIF for select patients. Future directions include a larger study to elucidate characteristics of the best candidates for outpatient RA MIS TLIF.

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.

Negotiating for new technologies: guidelines for the procurement of assistive technologies in spinal surgery: a narrative review

BACKGROUND AND OBJECTIVE

This is a narrative review with the objective to discuss available assistive technologies for spinal surgery. Characteristics, costs, and compatibility of the different systems are summarized and recommendations made regarding acquiring these technologies. The availability of assistive technologies in spine surgery continues to evolve rapidly. The literature is lacking a collective summary of the available technologies and guidelines for acquisition. This is a narrative review which (I) presents an up-to-date summary of the currently available assistive technologies in spinal surgery; (II) makes comment on the utility of imaging, navigation, and robotics; (III) makes recommendations for the utility of the platform based on hospital size and (IV) discuss factors involved in negotiating for the purchase of these new technologies.

METHODS

We assemble the most up-to-date collection of description, characteristics and pricing of assistive technologies in spinal surgery. We compare and contrast these technologies and make recommendations regarding acquisition.

KEY CONTENT AND FINDINGS

These technologies require a learning-curve for the surgeon and the operating room staff to understand how to use them efficiently. Surgeons need to be involved in the process of purchase decisions. Surgeons occupy a unique position in the health care infrastructure as their approach to care has significant ramifications on both the quality and cost of care. Surgeons should maintain conviction that their training and practice has allowed the use of these technologies to provide safer and more effective care for patients.

CONCLUSIONS

Assistive technologies and prostheses for spinal fusion are evolving rapidly. This article serves as an encompassing reference to the current technologies. These technologies will play a significant role in the delivery of spinal health care in the future. All stakeholders stand to benefit from the increased value these technologies bring to patient care.

Ninety-day complication, revision, and readmission rates for current-generation robot-assisted thoracolumbar spinal fusion surgery: results of a multicenter case series

OBJECTIVE

Robotics is a major area for research and development in spine surgery. The high accuracy of robot-assisted placement of thoracolumbar pedicle screws is documented in the literature. The authors present the largest case series to date evaluating 90-day complication, revision, and readmission rates for robot-assisted spine surgery using the current generation of robotic guidance systems.

METHODS

An analysis of a retrospective, multicenter database of open and minimally invasive thoracolumbar instrumented fusion surgeries using the Mazor X or Mazor X Stealth Edition robotic guidance systems was performed. Patients 18 years of age or older and undergoing primary or revision surgery for degenerative spinal conditions were included. Descriptive statistics were used to calculate rates of malpositioned screws requiring revision, as well as overall complication, revision, and readmission rates within 90 days.

RESULTS

In total, 799 surgical cases (Mazor X: 48.81%; Mazor X Stealth Edition: 51.19%) were evaluated, involving robot-assisted placement of 4838 pedicle screws. The overall intraoperative complication rate was 3.13%. No intraoperative implant-related complications were encountered. Postoperatively, 129 patients suffered a total of 146 complications by 90 days, representing an incidence of 16.1%. The rate of an unrecognized malpositioned screw resulting in a new postoperative radiculopathy requiring revision surgery was 0.63% (5 cases). Medical and pain-related complications unrelated to hardware placement accounted for the bulk of postoperative complications within 90 days. The overall surgical revision rate at 90 days was 6.63% with 7 implant-related revisions, representing an implant-related revision rate of 0.88%. The 90-day readmission rate was 7.13% with 2 implant-related readmissions, representing an implant-related readmission rate of 0.25% of cases.

CONCLUSIONS

The results of this multicenter case series and literature review suggest current-generation robotic guidance systems are associated with low rates of intraoperative and postoperative implant-related complications, revisions, and readmissions at 90 days. Future outcomes-based studies are necessary to evaluate complication, revision, and readmission rates compared to conventional surgery.

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.

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.

Comparison of accuracy and safety between robot-assisted and conventional fluoroscope assisted placement of pedicle screws in thoracolumbar spine: A meta-analysis

OBJECTIVE

The purpose of this systematic review and meta-analysis is to explore the screw positioning accuracy, complications related to pedicle screw implantation, revision rate and radiation exposure between robot screw placement and traditional fluoroscopic screw placement.

METHODS

We searched several databases, including CNKI, Wanfang database, cqvip datebase, PubMed, Cochrane library and EMBASE, to identify articles that might meet the criteria. Meta-analysis was performed using Revman 5.3 software.

RESULTS

A total of 13 randomized controlled trial were included. The results showed that the pedicle screw accuracy of the robot assisted group was significantly better than that of the conventional freehand (FH) group (OR = 3.5, 95% confidence interval [CI] [2.75,4.45], P < .0001). There was no significant difference in the complications caused by pedicle screw implantation between the robot-assisted group and the conventional FH group [OR = 0.39, 95%CI (0.10,1.48), P = .17]. The rate of facet joint invasion in the robot-assisted group was significantly lower than that in the conventional FH group (OR = 0.06, 95%CI [0.01,0.29], P = .0006). The revision rate in the robot-assisted group was significantly lower than that in the conventional FH group (OR = 0.19, 95%CI [0.05,0.71], P = 0.0.01). There was no significant difference in the average radiation of pedicle screws implantation between the robot-assisted group and the conventional FH (mean difference = -7.94, 95%CI [-20.18,4.30], P = .20).

CONCLUSION

The robot-assisted group was significantly better than the conventional FH in the accuracy of pedicle screw placement and facet joint invasion rate and revision rate. There was no significant difference in the complication and fluoroscopy time between the two groups.

Can Postoperative CT Imaging in Spine Surgery Be Replaced by Intraoperative 3D Rotation With the C-Arm?: Results of a Prospective Single Center Cohort Study

Objective: Dorsal instrumentation of the spine is an established treatment option for a range of spinal pathologies. Intraoperative fluoroscopy connected with navigation minimize the risk of incorrect screws placement. In several cases, post-operative CT scans are needed to verify possible mismatches. In this study, we evaluated the efficacy of 3D intraoperative fluoroscopy as compared to post-operative CT and the need of post-operative CT.

Methods: We conducted a prospective single-center cohort study, 94 patients were included. The screws were implanted using 3D rotation with C-arm and navigation system. The definitive position of the screws was verified by a post-operative CT scan. Finally, we compared the discrepance between intraoperative imaging and post-operative CT scan using Rampersaud-grade (A-D).

Results: 607 screws in 94 patients were included. Some 3% of the screws had to be replaced immediately intraoperative due to inadequate position with lateral or medial trajectory. An A-score was achieved for 85.5% of the 3D controlled screws and 87% of the post-operative CT. A B-score was found in 11.5% of either groups. In the 3D group a C-score was achieved for 2.5% and in the CT group for 0.8%. A D-score was found in 0.5% of the screws in both groups, p = 0.45. Only a mismatch of 3% could be detected for the intraoperative and post-operative imaging results.

Conclusion: Our study data shows that the placement of screws using the 3D rotation and navigation tool is safe and accurate. There were no relevant mismatches between intraoperative images and the post-operative CT.

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.

Evaluation of K-wireless robotic and navigation assisted pedicle screw placement in adult degenerative spinal surgery: learning curve and technical notes

Background

K-wireless robotic pedicle screw instrumentation with navigation is a new technology with large potential. Barriers to adoption are added registration time with robotic-navigated system and reliable screw positioning. Understanding the learning curve and limitations is crucial for successful implementation. The purpose of this study was to describe a learning curve of k-wireless robotic assisted pedicle screw placement with navigation and compare to conventional techniques.

Methods

A retrospective review of prospectively collected data of 65 consecutive adult patients underwent robotic-navigated posterior spinal fusion by a single spine surgeon. Registration, screw placement, and positioning times were recorded. All patients underwent intra-operative 3D fluoroscopy and screw trajectory was compared to pre-operative CT.

Results

A total of 364 instrumented pedicles were planned robotically, 311 (85.4%) were placed robotically; 17 screws (4.7%) converted to k-wire, 21 (5.8%) converted to freehand, and 15 (4.1%) planned freehand. Of the 311 robotically placed pedicle screws, three dimensional fluoroscopic imaging showed 291 (93.5%) to be GRS Grade A in the axial plane (fully contained within the pedicle) and 281 (90.4%) were GRS Grade A in the sagittal plane. All breached screw deviations from plan were identified on 3D fluoroscopy during surgery and repositioned and confirmed by additional 3d fluoroscopy scan. Reasons for conversion included morphology of starting point (n=18), soft tissue pressure (n=9), hypoplastic pedicles (n=6), obstructive reference pin placement (n=2), and robotic arm issues (n=1). Seventeen (5.5%) critical breaches (≥2-4 mm) were recorded in 11 patients, 9 (2.9%) critical breaches were due to soft tissue pressure causing skive. Two patients experienced 6 (1.9%) critical breaches from hypoplastic pedicles, and 3 (0.9%) unplanned lateral breaches were found in another patient. One patient (0.3%) experienced skive due to morphology and spinal instability from isthmic spondylolisthesis. Imaging showed 143 screws placed medially to plan (1.2±0.9 mm), 170 lateral (1.2±1.1 mm), 193 screws caudal (1.0±0.6 mm) and 117 cranial (0.6±0.5 mm). No adverse clinical sequelae occurred from implantation of any screw.

Conclusions

The learning curve showed improvement in screw times for the first several cases. Understanding the learning curve and situations where the robotic technique may be suboptimal can help guide the surgeon safe and effectively for adoption, as well as further refine these technologies.

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.

Robot-assisted minimally invasive transforaminal lumbar interbody fusion versus open transforaminal lumbar interbody fusion: a retrospective matched-control analysis for clinical and quality-of-life outcomes

Aim: To compare the screw accuracy and clinical outcomes between robot-assisted minimally invasive transforaminal lumbar interbody fusion (RA MIS-TLIF) and open TLIF in the treatment of one-level lumbar degenerative disease. Materials & methods: From May 2018 to December 2019, a consecutive series of patients undergoing robot-assisted minimally invasive one-level lumbar fusion procedures were retrospectively compared with matched controls who underwent one-level open TLIF procedures for clinical and quality-of-life outcomes. Results: A total of 52 patients underwent RA MIS-TLIF procedures (robot-assisted [RA] group) and 52 matched controls received freehand open TLIF procedures (open [OP] group). The RA group had more grade A screws with 96.2% one-time success rate of screw placement (p < 0.05). Besides, the RA group experienced less intraoperative blood loss and shorter length of hospital stay, while the OP group had shorter operative duration and cumulative radiation time (p < 0.001). What is more, the average VAS score for low back pain and ODI score in the RA group were lower than that in the OP group 1 month after operation (p < 0.05). Conclusion: The use of real-time, image-guided robot system may further expand the advantages of MIS-TLIF technique in terms of accuracy and safety.

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.

Reduction in complication and revision rates for robotic-guided short-segment lumbar fusion surgery: results of a prospective, multi-center study

Studies evaluating robotic guidance in lumbar fusion are limited primarily to evaluation of screw accuracy and perioperative complications. This is the first study to evaluate granular differences in short and long-term complication and revision rate profiles between robotic (RG) fluoroscopic (FG) guidance for minimally invasive short-segment lumbar fusions. A retrospective analysis of a prospective, multi-center database was performed. Complications were subdivided into surgical (further subcategorized into adjacent segment disease, new-onset back pain, radiculopathy, motor-deficit, hardware failure, pseudoarthrosis), wound, and medical complications. Complication and revision rates were compared between RG and FG groups cumulatively at 30, 90 days, and 1 year. 374 RG and 111 FG procedures were performed. RG was associated with an 86.25, 83.20, and 69.42% cumulative reduction in complication rate at 30, 90 days, and 1 year, respectively, compared to FG (p < 0.001). At all follow-up points, new-onset radiculopathy and medical complications were most prevalent in both groups. The greatest reductions in complication rates were seen for new-onset back pain (88.13%; p = 0.001) and wound complications (95.05%; p < 0.001) at 30 days, new-onset motor deficits (90.11%; p = 0.004) and wound complications (85.16%; p < 0.001) at 90 days, and new-onset motor deficits (85.16%; p = 0.002), wound (85.16%; p < 0.001), and medical complications (75.72%; p < 0.001) at 1 year. RG was associated with a 92.58% (p = 0.002) reduction in revision rate at 90 days and a 66.08% (p = 0.026) reduction at 1 year. RG was associated with significant reductions in postoperative complication rates at all follow-up time points and significant reductions in revision rates at 90 days and 1 year.

Magnetic resonance imaging-based synthetic computed tomography of the lumbar spine for surgical planning: a clinical proof-of-concept

OBJECTIVE

Computed tomography scanning of the lumbar spine incurs a radiation dose ranging from 3.5 mSv to 19.5 mSv as well as relevant costs and is commonly necessary for spinal neuronavigation. Mitigation of the need for treatment-planning CT scans in the presence of MRI facilitated by MRI-based synthetic CT (sCT) would revolutionize navigated lumbar spine surgery. The authors aim to demonstrate, as a proof of concept, the capability of deep learning-based generation of sCT scans from MRI of the lumbar spine in 3 cases and to evaluate the potential of sCT for surgical planning.

METHODS

Synthetic CT reconstructions were made using a prototype version of the "BoneMRI" software. This deep learning-based image synthesis method relies on a convolutional neural network trained on paired MRI-CT data. A specific but generally available 4-minute 3D radiofrequency-spoiled T1-weighted multiple gradient echo MRI sequence was supplemented to a 1.5T lumbar spine MRI acquisition protocol.

RESULTS

In the 3 presented cases, the prototype sCT method allowed voxel-wise radiodensity estimation from MRI, resulting in qualitatively adequate CT images of the lumbar spine based on visual inspection. Normal as well as pathological structures were reliably visualized. In the first case, in which a spiral CT scan was available as a control, a volume CT dose index (CTDIvol) of 12.9 mGy could thus have been avoided. Pedicle screw trajectories and screw thickness were estimable based on sCT findings.

CONCLUSIONS

The evaluated prototype BoneMRI method enables generation of sCT scans from MRI images with only minor changes in the acquisition protocol, with a potential to reduce workflow complexity, radiation exposure, and costs. The quality of the generated CT scans was adequate based on visual inspection and could potentially be used for surgical planning, intraoperative neuronavigation, or for diagnostic purposes in an adjunctive manner.

Risk of Postoperative Complications and Revision Surgery Following Robot-assisted Posterior Lumbar Spinal Fusion

STUDY DESIGN

Retrospective Study.

OBJECTIVE

This investigation examined matched cohorts of lumbar spinal fusion (LSF) patients undergoing robot-assisted and conventional LSF to compare risk of revision, 30-day readmission, 30-day complications, and postoperative opioid utilization.

SUMMARY OF BACKGROUND DATA

Patient outcomes and complication rates associated with robot-assisted LSF compared to conventional fusion techniques are incompletely understood.

METHODS

The PearlDiver Research Program (www.pearldiverinc.com) was used to identify patients undergoing primary LSF between 2011 and 2017. Patients receiving robot-assisted or conventional LSF were matched using key demographic and comorbidity variables. Indication for revision was also studied. Risk of revision, 30-day readmission, 30-day complications, and postoperative opioid utilization at 1 and 6 months was compared between the cohorts using multivariable logistic regression additionally controlling for age, sex, and Charlson Comorbidity Index.

RESULTS

The percent of LSFs that were robot-assisted rose by 169% from 2011 to 2017, increasing linearly each year (p = 0.0007). Matching resulted in 2528 patients in each cohort for analysis. Robot-assisted LSF patients experienced higher risk of revision (adjusted odds ratio [aOR] = 2.35, P ≤ 0.0001), 30-day readmission (aOR = 1.39, P = 0.0002), and total 30-day complications (aOR = 1.50, P < 0.0001), specifically respiratory (aOR = 1.56, P = 0.0006), surgical site infection (aOR = 1.56, P = 0.0061), and implant-related complications (aOR = 1.74, P = 0.0038). The risk of revision due to infection after robot-assisted LSF was an estimated 4.5-fold higher (aOR = 4.46, 95% confidence interval [CI] 1.95-12.04, P = 0.0011). Furthermore, robot-assisted LSF had increased risk of revision due to instrument failure (aOR = 1.64, 95% CI 1.05-2.58, P = 0.0300), and pseudarthrosis (aOR = 2.24, 95%CI = 1.32-3.95, P = 0.0037). A higher percentage of revisions were due to infection in robot-assisted LSF (19.0%) than in conventional LSF (9.2%) (P = 0.0408).

CONCLUSION

Robotic-assisted posterior LSF is independently associated with increased risk of revision surgery, infection, instrumentation complications, and postoperative opioid utilization compared to conventional fusion techniques. Further research is needed to investigate long-term postoperative outcomes following robot-assisted LSF. Spine surgeons should be cautious when considering immediate adoption of this emerging surgical technology.

LEVEL OF EVIDENCE

3.

Robot-Guided Transforaminal Versus Robot-Guided Posterior Lumbar Interbody Fusion for Lumbar Degenerative Disease

Objective

There have been no clinical studies comparing different robotic techniques. We compare minimally invasive, robot-guided transforaminal lumbar interbody fusion (RG-TLIF) and mini-open robot-guided posterior lumbar interbody fusion (RG-PLIF).

Methods

Using data from a prospective institutional registry, we identified 38 patients who underwent RG-PLIF. Propensity score matching using a nearest-neighbor algorithm was implemented to select RG-TLIF controls. Twelve-month patient-reported outcome measures are presented. A reduction of ≥ 30% from baseline was defined as the minimum clinically important difference (MCID).

Results

Among the 76 included patients, there was no difference between RG-TLIF and RG-PLIF in surgical time (132.3 ± 29.4 minutes vs. 156.5 ± 53.0 minutes, p = 0.162), length of stay (55.9 ± 20.0 hours vs. 57.2 ± 18.8 hours, p = 0.683), and radiation dose area product (310.6 ± 126.1 mGy × cm² vs. 287.9 ± 90.3 mGy × cm², p = 0.370). However, while there was no difference among the 2 groups in terms of raw postoperative patient-reported outcome measures scores (all p > 0.05), MCID in leg pain was greater for RG-PLIF (55.3% vs. 78.9%, p = 0.028), and MCID in Oswestry Disability Index was greater for RG-TLIF (92.1% vs. 68.4%, p = 0.009). There was no difference concerning back pain (81.6% vs. 68.4%, p = 0.185).

Conclusion

Our findings suggest that both RG-TLIF and RG-PLIF are viable and equally effective techniques in robotic spine surgery.

Global adoption of robotic technology into neurosurgical practice and research

Recent technological advancements have led to the development and implementation of robotic surgery in several specialties, including neurosurgery. Our aim was to carry out a worldwide survey among neurosurgeons to assess the adoption of and attitude toward robotic technology in the neurosurgical operating room and to identify factors associated with use of robotic technology. The online survey was made up of nine or ten compulsory questions and was distributed via the European Association of the Neurosurgical Societies (EANS) and the Congress of Neurological Surgeons (CNS) in February and March 2018. From a total of 7280 neurosurgeons who were sent the survey, we received 406 answers, corresponding to a response rate of 5.6%, mostly from Europe and North America. Overall, 197 neurosurgeons (48.5%) reported having used robotic technology in clinical practice. The highest rates of adoption of robotics were observed for Europe (54%) and North America (51%). Apart from geographical region, only age under 30, female gender, and absence of a non-academic setting were significantly associated with clinical use of robotics. The Mazor family (32%) and ROSA (26%) robots were most commonly reported among robot users. Our study provides a worldwide overview of neurosurgical adoption of robotic technology. Almost half of the surveyed neurosurgeons reported having clinical experience with at least one robotic system. Ongoing and future trials should aim to clarify superiority or non-inferiority of neurosurgical robotic applications and balance these potential benefits with considerations on acquisition and maintenance costs.

The Role of Intraoperative Image Guidance Systems (Three-Dimensional C-arm versus O-arm) in Spinal Surgery: Results of a Single-Center Study

OBJECTIVE

Spinal dorsal instrumentation is an established treatment option for a range of spinal disorders. In combination with navigation, intraoperative fluoroscopy reduces the risk of incorrectly placing screws. This study aimed to evaluate the efficacy and validity of fluoroscopy (intraoperative navigation with three-dimensional rotation of C-arm vs. O-arm).

METHODS

In this retrospective single-center study, 240 patients were included between July 2017 and April 2020. Intraoperative images were acquired using a Siemens-Arcadis Orbic 3D C-arm with a navigation system (Brainlab, AG, Munich, Germany) or using O-arm (Medtronic, Minneapolis, Minnesota, USA) with a navigation system (S7 StealthStation). Finally, we compared mismatches between intraoperative and postoperative computed tomography imaging results using Rampersaud-grade (A-D).

RESULTS

A total of 1614 screws were included: 94 patients in the C-arm group (cAG) and 146 in the O-arm group (oAG). In cAG, 3% (n = 20) of the screws had to be replaced directly due to inadequate positioning with median or lateral breaches, and 3.5 % of screws in oAG (n = 35). An A-score was achieved for 85.7% in the cAG and 87.4% in the oAG. A B-score was found in 11.5% in the cAG and 11.9% in the oAG. In the cAG, a C-score was achieved for 2.5% and in oAG for 0.7%. For 0.3% of the screws, a D-score was found in cAG and for none in oAG.

CONCLUSIONS

Our study shows that placement of screws using intraoperative imaging in combination with a navigation tool is accurate. Furthermore, navigation coupled with the O-arm had significant advantages in accuracy over navigation with 3D C-arm fluoroscopy. However, both systems offer a high level of accuracy.

A cadaveric precision and accuracy analysis of augmented reality-mediated percutaneous pedicle implant insertion

OBJECTIVE

Augmented reality-mediated spine surgery (ARMSS) is a minimally invasive novel technology that has the potential to increase the efficiency, accuracy, and safety of conventional percutaneous pedicle screw insertion methods. Visual 3D spinal anatomical and 2D navigation images are directly projected onto the operator's retina and superimposed over the surgical field, eliminating field of vision and attention shift to a remote display. The objective of this cadaveric study was to assess the accuracy and precision of percutaneous ARMSS pedicle implant insertion.

METHODS

Instrumentation was placed in 5 cadaveric torsos via ARMSS with the xvision augmented reality head-mounted display (AR-HMD) platform at levels ranging from T5 to S1 for a total of 113 total implants (93 pedicle screws and 20 Jamshidi needles). Postprocedural CT scans were graded by two independent neuroradiologists using the Gertzbein-Robbins scale (grades A-E) for clinical accuracy. Technical precision was calculated using superimposition analysis employing the Medical Image Interaction Toolkit to yield angular trajectory (°) and linear screw tip (mm) deviation from the virtual pedicle screw position compared with the actual pedicle screw position on postprocedural CT imaging.

RESULTS

The overall implant insertion clinical accuracy achieved was 99.1%. Lumbosacral and thoracic clinical accuracies were 100% and 98.2%, respectively. Specifically, among all implants inserted, 112 were noted to be Gertzbein-Robbins grade A or B (99.12%), with only 1 medial Gertzbein-Robbins grade C breach (> 2-mm pedicle breach) in a thoracic pedicle at T9. Precision analysis of the inserted pedicle screws yielded a mean screw tip linear deviation of 1.98 mm (99% CI 1.74-2.22 mm) and a mean angular error of 1.29° (99% CI 1.11°-1.46°) from the projected trajectory. These data compare favorably with data from existing navigation platforms and regulatory precision requirements mandating that linear and angular deviation be less than 3 mm (p < 0.01) and 3° (p < 0.01), respectively.

CONCLUSIONS

Percutaneous ARMSS pedicle implant insertion is a technically feasible, accurate, and highly precise method.

The impact of robot-assisted spine surgeries on clinical outcomes: A systemic review and meta-analysis

BACKGROUND

Medical robotics has enabled a significant advancement in the field of modern spine surgery, especially in pedicle screw fixation. A plethora of studies focused on the accuracy of pedicle fixation in robotic-assisted (RA) technology. However, it is not clear whether RA techniques can improve patients' clinical outcomes.

METHODS

We retrieved relevant studies that compare the differences between RA and freehand (FH) techniques in spine surgeries from the following databases: PubMed, Embase, Cochrane Library and Web of Science. The perioperative outcomes of this technology were measured with parameters including radiation exposure, operative time, the length of hospital stay, complication rates and revision rates. Two reviewers independently reviewed the studies in our sample, assessed their validity and extracted relevant data.

RESULTS

Our search resulted in a sample of 23 eligible studies, which involved 1247 patients (5042 pedicle screws) in the RA group and 1273 patients (4830 pedicle screws) in the FH group. With regard to the radiation exposure, the fluoroscopy time was less in surgeries assisted by Mazor robots (standard mean difference [SMD] = -0.96, 95% CI = -1.60 to -0.31) but more in Tianji robots (SMD = 0.91, 95% CI = 0.17 to 1.66) and ROSA robots (SMD = 2.57, 95% CI = 2.01 to 3.13). For radiation dose, a decrease was observed in Tianji robots (SMD = -1.59, 95% CI = -2.13 to -1.05). In the lumbar subgroup, the use of robots increased the operative time (SMD = 0.53, 95% CI = 0.19 to 0.86). In the degenerative diseases (DG) group, there was a significant decrease in the length of hospital stay when robots were introduced (SMD = -0.30, 95% CI = -0.48 to -0.12). While in the DF (deformity) and DG group, a significant increase was found (SMD = 0.17, 95% CI = 0.02 to 0.32). The complication (OR = 0.41, 95% CI = 0.26 to 0.66) and the revision rates (OR = 0.38, 95% CI = 0.24 to 0.60) showed a significant decrease in the RA group compared to the conventional FH group.

CONCLUSIONS

This study suggests that RA spine surgeries would result in fewer complications, a lower revision rate and shorter length of hospital stay. As the technology continues to evolve, we may expect more applications of robotic systems in spine surgeries.

Comparison of robot-assisted and freehand pedicle screw placement for lumbar revision surgery

BACKGROUND

The accuracy of robot-assisted pedicle screw implantation is a safe and effective method in lumbar surgery, but it still remains controversial in lumbar revision surgery. This study evaluated the clinical safety and accuracy of robot-assisted versus freehand pedicle screw implantation in lumbar revision surgery.

METHODS

This was a retrospective study. From January 2018 to December 2019, 81 patients underwent posterior lumbar revision surgery in our hospital. Among them, 39 patients underwent revision surgery performed with robot-assisted pedicle screw implantation (Renaissance robotic system), whereas the remaining 42 patients underwent traditional freehand pedicle screw implantation. All patients underwent magnetic resonance imaging (MRI), computed tomography (CT), and X-ray before revision surgery. The sex, age, body mass index, bone mineral density, operative time, blood loss, operative segments, intra-operative fluoroscopy time, and complications were compared between the two groups. The accuracy of pedicle screw implantation was measured on CT scans based on Gertzbein Robbins grading, and the invasion of superior level facet joint was evaluated by Babu's method.

RESULTS

There was no statistical difference about the baseline between the two groups (P > 0.05). Although there were no significant differences in operative time and complications between the two groups (P > 0.05), the robot-assisted group had significantly less intra-operative blood loss and shorter intra-operative fluoroscopy times than the freehand group (P < 0.05). In the robot-assisted group, a total of 267 screws were inserted, which were marked as grade A in 250, grade B in 13, grade C in four, and no grade D or E in any screw. In terms of invasion of superior level facet joint, a total of 78 screws were inserted in the robot-assisted group, which were marked as grade 0 in 73, grade 1 in four, grade 2 in one, and grade 3 in zero. By comparison, 288 screws were placed in total in the freehand group, which were rated as grade A in 251, grade B in 28, grade C in eight, grade D in one, and no grade E in any screw. A total of 82 superior level facet joint screws were inserted in freehand group, which were marked as grade 0 in 62, grade one in 18, grade 2 in two, and grade 3 in zero. The robot-assisted technique was statistically superior to the freehand method in the accuracy of screw placement (P < 0.05).

CONCLUSION

Compared with freehand screw implantation, in lumbar revision surgery, the Renaissance robot had higher accuracy and safety of pedicle screw implantation, fewer superior level facet joint violations, and less intra-operative blood loss and intra-operative fluoroscopy time.

Next-Generation Robotic Spine Surgery: First Report on Feasibility, Safety, and Learning Curve

BACKGROUND

Pedicle screw placement is a commonly performed procedure. Robot-guided screw placement is a recent technological advance that has shown accuracy and reliability with first-generation platforms.

OBJECTIVE

To report our initial experience with the safety, feasibility, and learning curve associated with pedicle screw placement utilizing next-generation robotic guidance.

METHODS

A retrospective chart review was conducted to obtain data for 20 patients who underwent lumbar pedicle screw placement under robotic guidance after undergoing interbody fusion for lumbar spinal stabilization for degenerative disc disease with or without spondylolisthesis. The newest generation Mazor X (Mazor Robotics Ltd, Caesarea, Israel) was used. Accuracy of screw placement was determined to be grade I to IV. Grade I was in the pedicle (no breach/deviation), grade II was breach < 2 mm, grade III was breach 2 to 4 mm, and grade IV was breach >4 mm; breach direction (superior, lateral, inferior, or medial) was also recorded.

RESULTS

Twenty patients underwent robotically assisted pedicle screw placement of 75 screws at 24 levels. Seventy-four screw placements (98.7%) were grade I; 1 (1.3%) was grade II (medial). No complications occurred. Mean time for screw insertion was 3.6 min. Mean fluoroscopy time was 13.1 s and mean radiation dose was 29.9 mGy.

CONCLUSION

We found that next-generation robotic spine surgery was safe and feasible with reliable and precise accuracy and a minimal learning curve. As this technology improves, further novel applications are expected to develop. Further research is needed to determine long-term efficacy.

Improving recovery after elective degenerative spine surgery: 5-year experience with an enhanced recovery after surgery (ERAS) protocol

OBJECTIVEEnhanced recovery after surgery (ERAS) has led to a paradigm shift in various surgical specialties. Its application can result in substantial benefits in perioperative healthcare utilization through preoperative physical and mental patient optimization and modulation of the recovery process. Still, ERAS remains relatively new to spine surgery. The authors report their 5-year experience, focusing on ERAS application to a broad population of patients with degenerative spine conditions undergoing elective surgical procedures, including anterior lumbar interbody fusion (ALIF).METHODSA multimodal ERAS protocol was applied between November 2013 and October 2018. The authors analyze hospital stay, perioperative outcomes, readmissions, and adverse events obtained from a prospective institutional registry. Elective tubular microdiscectomy and mini-open decompression as well as minimally invasive (MI) anterior or posterior fusion cases were included. Their institutional ERAS protocol contains 22 pre-, intra-, and postoperative elements, including preoperative patient counseling, MI techniques, early mobilization and oral intake, minimal postoperative restrictions, and regular audits.RESULTSA total of 2592 consecutive patients were included, with 199 (8%) undergoing fusion. The mean hospital stay was 1.1 ± 1.2 days, with 20 (0.8%) 30-day and 36 (1.4%) 60-day readmissions. Ninety-four percent of patients were discharged after a maximum 1-night hospital stay. Over the 5-year period, a clear trend toward a higher proportion of patients discharged home after a 1-night stay was observed (p < 0.001), with a concomitant decrease in adverse events in the overall cohort (p = 0.025) and without increase in readmissions. For fusion procedures, the rate of 1-night hospital stays increased from 26% to 85% (p < 0.001). Similarly, the average length of hospital stay decreased steadily from 2.4 ± 1.2 days to 1.5 ± 0.3 days (p < 0.001), with a notable concomitant decrease in variance, resulting in an estimated reduction in nursing costs of 46.8%.CONCLUSIONSApplication of an ERAS protocol over 5 years to a diverse population of patients undergoing surgical procedures, including ALIF, for treatment of degenerative spine conditions was safe and effective, without increase in readmissions. The data from this large case series stress the importance of the multidisciplinary, iterative improvement process to overcome the learning curve associated with ERAS implementation, and the importance of a dedicated perioperative care team. Prospective trials are needed to evaluate spinal ERAS on a higher level of evidence.

A minimally invasive, 3D-fluoroscopy-navigation-guided, 3D-controlled pedicle approach in spine surgery: first reliable results and impact on patient safety

PURPOSE

Safe pedicle screw placement is a daily challenge to every spine surgeon. Introduction of minimally invasive approaches in spinal surgery led to an impaired facility of inspection of the surgical field increasing the importance of intraoperative imaging and navigation. During the past years, we established a minimally invasive, navigated approach in our clinical setting.

METHODS

We retrospectively reviewed the accuracy of pedicle approaches in patients treated due to traumatic or osteoporotic fractures, spondylitis/discitis, and tumoral lesions. Guide wires for pedicle screws or kyphoplasty cannulas were inserted in a 3D-navigation-guided, minimally invasive technique. Positioning of the guide wires was verified via 3D-scan, and pedicle screws/kyphoplasty cannulas were then visualized via a.p./lateral radiographs. Accuracy data were compared to a standard navigated open approach control group with indications similar to the MIS-group.

RESULTS

23 MIS patients were included in this study (25-84 years, mean 70 years) with a total of 154 placed guide wires. Handling of the navigated Jamshidi needle was easy and secure. The guide wires showed correct placement in 151/154 cases. Three wires (1.9%) needed correction of placement after control scan. There were no vascular or neurologic complications due to wire misplacement. In the open-surgery control group, 7/181 screws (3.9%) needed intraoperative correction presenting no significant difference compared to the correction rate of the MIS-group (p = 0.35).

CONCLUSION

Our study shows the feasibility and reliability of a navigation-guided, minimally invasive pedicle approach in the clinical setting. Therefore, reduced morbidity due to minimized approaches can be combined with higher accuracy of navigated pedicle screw/kyphoplasty cannula placement improving patient safety.

Revision after spinal stenosis surgery

PURPOSE

To make a literature review on spinal stenosis recurrence after a first surgery and edit rules to avoid this complication.

METHODS

We conducted two separate PUBMED searches to evaluate the revision post-stenosis and degenerative scoliosis surgery using the terms: lumbar vertebrae/surgery, spinal stenosis, spine, scoliosis and reoperation. The resulting papers were categorized into three groups: (1) those that evaluated reoperation post-simple decompression; (2) those that evaluated spinal decompression and fusion for short (3 levels or less) or long (more than 3 levels) segment spinal fusion; and (3) those diagnosing the stenosis during the surgery.

RESULTS

(1) We found 11 relevant papers that only looked at revision spine surgery post-laminectomy for spinal stenosis. (2) We found 20 papers looked at reoperation post-laminectomy and fusion amongst which there were two papers specifically comparing long-segment (> 3 level) and short-segment (3 or less levels) fusions. (3) In the unspecified group, we found only one article. Fifteen articles were excluded as they were not specifically looking at our objective criteria for revision surgery. In regard to revision post-adult deformity surgery, we found 18 relevant articles.

CONCLUSIONS

After this literature review and analysis of post-operative stenosis, it seems important to provide some advice to avoid revision surgeries more or less induced by the surgery. It looks interesting when performing simple decompression without fusion in the lumbar spine to analyse the risk of instability induced by the decompression and facet resection but also by a global balance analysis. Regarding pre-operative stenosis in a previously operated area, different causes may be evocated, like screw or cage malpositionning but also insufficient decompression which is a common cause. Intraoperatively, the use of neuromonitoring and intraoperative CT scan with navigation are useful tool in complex cases to avoid persisting stenosis. Pre-op analysis and planning are key parameters to decrease post-op problems. These slides can be retrieved under Electronic Supplementary Material.

[Short-term effectiveness comparison between robotic-guided percutaneous minimally invasive pedicle screw internal fixation and traditional open internal fixation in treatment of thoracolumbar fractures]

Objective

To compare short-term effectiveness between robot-guided percutaneous minimally invasive pedicle screw internal fixation and traditional open internal fixation in the treatment of thoracolumbar fractures.

Methods

The clinical data of 52 cases of thoracolumbar fracture without neurological injury symptoms admitted between January 2018 and May 2018 were retrospectively analyzed. According to the different surgical methods, they were divided into minimally invasive group (24 cases, treated with robot-assisted percutaneous minimally invasive pedicle screw internal fixation) and open group (28 cases, treated with traditional open internal fixation). There was no significant difference between the two groups in the general data such as gender, age, cause of injury, fracture segment, thoracolumbar injury classification and severity score (TLICS), preoperative back pain visual analogue scale (VAS) score, Oswestry disability index (ODI) score, fixed segment height, and fixed segment kyphosis Cobb angle ( P>0.05). The operation time, intraoperative blood loss, and hospitalization time of the two groups were recorded and compared; as well as the VAS score, ODI score, fixed segment height, and fixed segment kyphosis Cobb angle of the two groups before operation and at 3 days, 1 month, 6 months, and 10 months after operation. CT scan was reexamined at 1-3 days after operation, and the pedicle screw insertion accuracy rate was determined and calculated according to Gertzbein-Robbins classification standard.

Results

The operation time of the minimally invasive group was significantly longer than that of the open group, but the intraoperative blood loss and hospitalization time were significantly shorter than those of the open group ( P<0.05). There were 132 pedicle screws and 158 pedicle screws implanted in the minimally invasive group and the open group respectively. According to the Gertzbein-Robbins classification standard, the accuracy of pedicle screws was 97.7% (129/132) and 96.8% (153/158), respectively, showing no significant difference between the two groups ( χ ²=0.505, P=0.777). The patients in both groups were followed up 10 months, and there was no rejection or internal fixation fracture. In the minimally invasive group, the internal fixator was removed at 10 months after operation, but not in the open group. The VAS score, ODI score, fixed segment heigh, and fixed segment kyphotic Cobb angle of the two groups were improved in different degrees when compared with preoperative ones ( P<0.05). Except that the VAS score and ODI score of the minimally invasive group were significantly better than those of the open group at 3 days after operation ( P<0.05), there was no significant difference between the two groups at other time points ( P>0.05).

Conclusion

Robot-assisted percutaneous minimally invasive pedicle screw internal fixation for thoracolumbar fractures has significant advantages in intraoperative blood loss, hospitalization time, and early postoperative effectiveness and other aspects, and the effect of fracture reduction is good.

A preliminary study of a novel robotic system for pedicle screw fixation: A randomised controlled trial

Background and objective

Existing orthopaedic robotic systems are almost restricted to provide guidance for trajectory direction. In the present study, a novel spinal robotic system with automatic drilling power was introduced. The aim of this study is to evaluate the feasibility and safety in pedicle screw ​insertion of posterior lumbar interbody fusion assisted by this novel robotic system.

Methods and materials

A randomised controlled trial was conducted for 17 participants who were required posterior lumbar interbody fusion process. Seven (3 M/4 F) were randomly assigned to the robot-assisted group (RA group), and the other ten (4 M/6 F) were assigned to the conventional technique group (FH group). A novel robotic system was used in the RA group. All measurements were based on postoperative computed tomography (CT) data. Accuracy of screw insertion was determined using the Gertzbein and Robbins Scale. Precision was measured by the entry point deviation distance and the trajectory rotation. Other variables included operation time, radiation time, length of stay, and screw-related complications.

Result

A total of 82 pedicle screws were placed in the 17 participants. In the RA group, 90.6% of screws placed were Grade A, and 9.4% were Grade B. In the FH group, 78.0% of screws were Grade A, 20.0% were Grade B, and 2.0% were Grade C. No statistical difference was found in the operation time, radiation time per case, and length of stay between both groups. The radiation time per screw is significantly lower in the RA group. No screw-related complications or revision occurred in the present study.

Conclusion

The outcome of screw accuracy of this robotic system was comparable with that of experienced surgeons, and no screw-related complication was found in the RA group during hospitalisation. In addition, radiation time per screw in the robotic group was significantly lower than that in the conventional group, which shows the potential to reduce radiation exposure of pedicle screw fixation assisted by this robotic system.

Translational potential

Our study shows that pedicle screw fixation assisted by "Orthbot" system is accurate and safe. It is concluded that this novel robotic system offers a new option for internal implantation in spine surgery.

Robotic navigation during spine surgery

Introduction: Potential complications associated with screw malposition may result in neurological deficits or vascular injuries. Spine surgery has significantly developed under the assistance of technological progress. The advantages of applying robotic technology in spine surgery include the possibility of improving screw accuracy, reducing complications, decreasing fluoroscopy use.Areas covered: We critically evaluated the current literature on the radiographic and clinical outcomes of robotic-assisted spine surgery, including accuracy, radiation exposure, operative time, and complication rates.Expert opinion: Robotic-assisted spine surgery shows promising results and has the potentials for further investigations. The robot-assisted spine surgery is appeared to be more accurate in pedicle screw placement than the free-hand technique. In general, the robot-assisted technique is associated with shorter radiation exposure time but longer operative time than free-hand technique. For higher accuracy of robotic-assisted spine surgery, technical advancement and high-quality researches are needed. Artificial intelligent technology, decompression function, and higher accuracy are the directions for the development of robotic-assisted spine surgery.

External validation of a prediction model for pain and functional outcome after elective lumbar spinal fusion

OBJECTIVE

Patient-reported outcome measures following elective lumbar fusion surgery demonstrate major heterogeneity. Individualized prediction tools can provide valuable insights for shared decision-making. We externally validated the spine surgical care and outcomes assessment programme/comparative effectiveness translational network (SCOAP-CERTAIN) model for prediction of 12-month minimum clinically important difference in Oswestry Disability Index (ODI) and in numeric rating scales for back (NRS-BP) and leg pain (NRS-LP) after elective lumbar fusion.

METHODS

Data from a prospective registry were obtained. We calculated the area under the curve (AUC), calibration slope and intercept, and Hosmer-Lemeshow values to estimate discrimination and calibration of the models.

RESULTS

We included 100 patients, with average age of 50.4 ± 11.4 years. For 12-month ODI, AUC was 0.71 while the calibration intercept and slope were 1.08 and 0.95, respectively. For NRS-BP, AUC was 0.72, with a calibration intercept of 1.02, and slope of 0.74. For NRS-LP, AUC was 0.83, with a calibration intercept of 1.08, and slope of 0.95. Sensitivity ranged from 0.64 to 1.00, while specificity ranged from 0.38 to 0.65. A lack of fit was found for all three models based on Hosmer-Lemeshow testing.

CONCLUSIONS

The SCOAP-CERTAIN tool can accurately predict which patients will achieve favourable outcomes. However, the predicted probabilities-which are the most valuable in clinical practice-reported by the tool do not correspond well to the true probability of a favourable outcome. We suggest that any prediction tool should first be externally validated before it is applied in routine clinical practice. These slides can be retrieved under Electronic Supplementary Material.

Predictors of loss of follow-up in a prospective registry: which patients drop out 12 months after lumbar spine surgery?

BACKGROUND CONTEXT

Long-term patient-reported outcomes (PROMs) are essential in clinical practice and research. Prospective trials and registries often struggle with high rates of loss of follow-up (LOFU), which may bias their findings. Little is known on risk factors for PROM nonresponse, especially for digitally mailed questionnaires.

PURPOSE

To elucidate which patients are at high risk for LOFU by identifying associated predictors.

STUDY DESIGN

Analysis of a prospective registry.

PATIENT SAMPLE

Patients that underwent surgery for degenerative lumbar disease were included.

OUTCOME MEASURES

Rate of PROM follow-up response at 12 months postoperatively.

METHODS

Preoperatively and at 12 months postoperatively, patients were asked to complete a range of PROM questionnaires using a web-based tool. All patients who successfully completed their baseline questionnaire were included. Patients were not actively reminded upon nonresponse. Univariate and independent predictors of LOFU at 12 months were identified.

RESULTS

We included 1,456 patients, of which 861 (59%) were lost to follow-up at 12 months. Univariately, lower age, American Society of Anesthesiologists (ASA) class 1, smoking, lack of prior surgery, higher pain scores and functional disability, and lower quality-of-life were associated with LOFU (all p<.05). Only lower age (OR: 0.98, p=.001), smoking (OR: 1.46, p=.019), lack of prior surgery (OR: 0.59, p=.019), and spondylolisthesis (OR: 0.47, p=.024) independently predicted LOFU.

CONCLUSIONS

In a prospective registry of lumbar spine surgery patients based on web-based outcome capturing, younger age, active smoking status, lack of prior surgery, and nonspondylolisthesis surgery were independent predictors of loss of follow-up. In the future, it may become possible to preoperatively identify patients at high-risk for study dropout. As the implementation of prospective registries and the use of automated follow-up methods are on the rise, it is crucial to ensure efficiency and reduce bias of the methods on which all clinical research is based on.

The European Robotic Spinal Instrumentation (EUROSPIN) study: protocol for a multicentre prospective observational study of pedicle screw revision surgery after robot-guided, navigated and freehand thoracolumbar spinal fusion

INTRODUCTION

Robotic guidance (RG) and computer-assisted navigation (NV) have seen increased adoption in instrumented spine surgery over the last decade. Although there exists some evidence that these techniques increase radiological pedicle screw accuracy compared with conventional freehand (FH) surgery, this may not directly translate to any tangible clinical benefits, especially considering the relatively high inherent costs. As a non-randomised, expertise-based study, the European Robotic Spinal Instrumentation Study aims to create prospective multicentre evidence on the potential comparative clinical benefits of RG, NV and FH in a real-world setting.

METHODS AND ANALYSIS

Patients are allocated in a non-randomised, non-blinded fashion to the RG, NV or FH arms. Adult patients that are to undergo thoracolumbar pedicle screw instrumentation for degenerative pathologies, infections, vertebral tumours or fractures are considered for inclusion. Deformity correction and surgery at more than five levels represent exclusion criteria. Follow-up takes place at 6 weeks, as well as 12 and 24 months. The primary endpoint is defined as the time to revision surgery for a malpositioned or loosened pedicle screw within the first postoperative year. Secondary endpoints include patient-reported back and leg pain, as well as Oswestry Disability Index and EuroQOL 5-dimension questionnaires. Use of analgesic medication and work status are recorded. The primary analysis, conducted on the 12-month data, is carried out according to the intention-to-treat principle. The primary endpoint is analysed using crude and adjusted Cox proportional hazards models. Patient-reported outcomes are analysed using baseline-adjusted linear mixed models. The study is monitored according to a prespecified monitoring plan.

ETHICS AND DISSEMINATION

The study protocol is approved by the appropriate national and local authorities. Written informed consent is obtained from all participants. The final results will be published in an international peer-reviewed journal.

TRIAL REGISTRATION NUMBER

Clinical Trials.gov registry NCT03398915; Pre-results, recruiting stage.

Learning Curve for Robot-Assisted Percutaneous Pedicle Screw Placement in Thoracolumbar Surgery

Study Design

Retrospective review of an initial cohort of consecutive patients undergoing robot-assisted pedicle screw placement.

Purpose

We aimed to evaluate the learning curve, if any, of this new technology over the course of our experience.

Overview of Literature

Percutaneous pedicle screws have specific advantages over open freehand screws. However, they require intraoperative imaging for their placement (e.g., fluoroscopy and navigation) and require increased surgeon training and skill with the learning curve estimated at approximately 20–30 cases. To our knowledge, this is the first study that measures the learning curve of robot-guided purely percutaneous pedicle screw placement with comprehensive objective postoperative computed tomography (CT) scoring, time per screw placement, and fluoroscopy time.

Methods

We included the first 80 consecutive patients undergoing robot-assisted spinal surgery at Melbourne Private Hospital. Data were collected for pedicle screw placement accuracy, placement time, fluoroscopy time, and revision rate. Patient demographic and relevant perioperative and procedural data were also collected. The patients were divided equally into four sub-groups as per their chronological date of surgery to evaluate how the learning curve affected screw placement outcomes.

Results

Total 80 patients were included; 73 (91%) had complete data and postoperative CT imaging that could help assess that placement of 352 thoracolumbar pedicle screws. The rate of clinically acceptable screw placement was high (96.6%, 95.4%, 95.6%, and 90.7%, in groups 1 to 4, respectively, p=0.314) over time. The median time per screw was 7.0 minutes (6.5, 7.0, 6.0, and 6.0 minutes in groups 1 to 4, respectively, p=0.605). Intraoperative revision occurred in only 1 of the 352 screws (0.3%).

Conclusions

We found that robot-assisted screw placement had high accuracy, low placement time, low fluoroscopy time, and a low complication rate. However, there were no significant differences in these parameters at the initial experience and the practiced, experience placement (after approximately 1 year), indicating that robot-assisted pedicle screw placement has a very short (almost no) learning curve.

Robotic Guidance in Minimally Invasive Spine Surgery: a Review of Recent Literature and Commentary on a Developing Technology

PURPOSE OF REVIEW

Minimally invasive spine surgery (MIS) and robotic technology are growing in popularity and are increasing utilized in combination. The purpose of this review is to identify the current successes, potential drawbacks, and future directions of robotic guidance for MIS compared to traditional techniques.

RECENT FINDINGS

Recent literature highlights successful incorporation of robotic guidance in MIS as a consistently accurate method for pedicle screw placement. With a short learning curve and low complication rates, robot guidance may also reduce the use of fluoroscopy, operative time, and length of hospital stay. Recent literature suggests that incorporating robotic guidance in MIS improves the accuracy of pedicle screw insertion and may have added benefits both intra- and postoperatively for the patient and provider. Future research should focus on direct comparison between MIS with and without robotic guidance.

The Arrival of Robotics in Spine Surgery: A Review of the Literature

STUDY DESIGN

Systematic review.

OBJECTIVE

The authors aim to review comparative outcome measures between robotic and free-hand spine surgical procedures including: accuracy of spinal instrumentation, radiation exposure, operative time, hospital stay, and complication rates.

SUMMARY OF BACKGROUND DATA

Misplacement of pedicle screws in conventional open as well as minimally invasive surgical procedures has prompted the need for innovation and allowed the emergence of robotics in spine surgery. Before incorporation of robotic surgery in routine practice, demonstration of improved instrumentation accuracy, operative efficiency, and patient safety are required.

METHODS

A systematic search of the PubMed, OVID-MEDLINE, and Cochrane databases was performed for articles relevant to robotic assistance of pedicle screw placement. Inclusion criteria were constituted by English written randomized control trials, prospective and retrospective cohort studies involving robotic instrumentation in the spine. Following abstract, title, and full-text review, 32 articles were selected for study inclusion.

RESULTS

Intrapedicular accuracy in screw placement and subsequent complications were at least comparable if not superior in the robotic surgery cohort. There is evidence supporting that total operative time is prolonged in robot-assisted surgery compared to conventional free-hand. Radiation exposure appeared to be variable between studies; radiation time did decrease in the robot arm as the total number of robotic cases ascended, suggesting a learning curve effect. Multilevel procedures appeared to tend toward earlier discharge in patients undergoing robotic spine surgery.

CONCLUSION

The implementation of robotic technology for pedicle screw placement yields an acceptable level of accuracy on a highly consistent basis. Surgeons should remain vigilant about confirmation of robotic-assisted screw trajectory, as drilling pathways have been shown to be altered by soft tissue pressures, forceful surgical application, and bony surface skiving. However, the effective consequence of robot-assistance on radiation exposure, length of stay, and operative time remains unclear and requires meticulous examination in future studies.

LEVEL OF EVIDENCE

4.

A Cost-Effectiveness Analysis of the Integration of Robotic Spine Technology in Spine Surgery

OBJECTIVE

We investigate the cost-effectiveness of adding robotic technology in spine surgery to an active neurosurgical practice.

METHODS

The time of operative procedures, infection rates, revision rates, length of stay, and possible conversion of open to minimally invasive spine surgery (MIS) secondary to robotic image guidance technology were calculated using a combination of institution-specific and national data points. This cost matrix was subsequently applied to 1 year of elective clinical case volume at an academic practice with regard to payor mix, procedural mix, and procedural revenue.

RESULTS

A total of 1,985 elective cases were analyzed over a 1-year period; of these, 557 thoracolumbar cases (28%) were analyzed. Fifty-eight (10.4%) were MIS fusions. Independent review determined an additional ~10% cases (50) to be candidates for MIS fusion. Furthermore, 41.4% patients had governmental insurance, while 58.6% had commercial insurance. The weighted average diagnosis-related group reimbursement for thoracolumbar procedures for the hospital system was calculated to be $25,057 for Medicare and $42,096 for commercial insurance. Time savings averaged 3.4 minutes per 1-level MIS procedure with robotic technology, resulting in annual savings of $5,713. Improved pedicle screw accuracy secondary to robotic technology would have resulted in 9.47 revisions being avoided, with cost savings of $314,661. Under appropriate payor mix components, robotic technology would have converted 31 Medicare and 18 commercial patients from open to MIS. This would have resulted in 140 fewer total hospital admission days ($251,860) and avoided 2.3 infections ($36,312). Robotic surgery resulted in immediate conservative savings estimate of $608,546 during a 1-year period at an academic center performing 557 elective thoracolumbar instrumentation cases.

CONCLUSION

Application of robotic spine surgery is cost-effective, resulting in lesser revision surgery, lower infection rates, reduced length of stay, and shorter operative time. Further research is warranted, evaluating the financial impact of robotic spine surgery.

Robotics in trauma and orthopaedics

Recent advances and review of literature

Cardiac Arrest During Spine Surgery in the Prone Position: Case Report and Review of the Literature

OBJECTIVE

Intraoperative cardiac arrest (CA) is usually attributable to pre-existing disease or intraoperative complications. In rare cases, intraoperative stress can demask certain genetic diseases, such as catecholaminergic polymorphic ventricular tachycardia (CPVT). It is essential that neurosurgeons be aware of the etiologies, risk factors, and initial management of CA during surgery with the patient in the prone position.

METHODS

We present a case of CA directly after spinal fusion for lumbar spondylolisthesis and review the literature on cardiac arrests during spinal neurosurgery in the prone position. We focus on etiologies of CA in patients with structurally normal hearts.

RESULTS

After resuscitation, a 53-years-old female patient achieved return of spontaneous circulation after 17 minutes, without any neurologic deficits and with substantial improvement of functional disability and pain scores. Extensive imaging, stress testing, and genetic screening ruled out common etiologies of CA. In this patient with a structurally normal heart, CPVT was established as the most likely cause. We identified 18 additional cases of CA associated with spinal neurosurgery in the prone position. Most cases occurred during deformity or fusion procedures. Commonly reported etiologies of CA were air embolism, hypovolemia, and dural traction leading to vasovagal response. In patients with structurally normal hearts, inherited arrhythmia syndromes including CPVT, Brugada syndrome, and long QT syndrome should be included in the differential diagnosis and specifically included in testing.

CONCLUSIONS

Although intraoperative CA is rare during spine surgery, neurosurgeons should be aware of the etiologies and the specific difficulties in the management associated with the prone position.