A Comparison of Spinal Robotic Systems and Pedicle Screw Accuracy Rates: Review of Literature and Meta-Analysis

Manuscript Title: Comparative Cost-Effectiveness Analysis between Navigated Robot-assisted platforms and O-arm navigation in Minimally Invasive Transforaminal Interbody Fusion (MIS-TLIF)

BACKGROUND CONTEXT

Minimal invasive Transforaminal Lumbar Interbody Fusion (TLIF) is an increasingly common procedure used in treating degenerative lumbar spine conditions. Advancement of robot-assisted technology has improved accuracy of instrumentation with smaller incisions, resulting in better surgical outcomes and shorter hospital stay.

PURPOSE

This study aims to assess cost effectiveness of robot-assisted minimally invasive TLIF (RA-TLIF) in our institution; and compare patient outcomes with conventional O-arm navigated minimally invasive TLIF (ON-TLIF).

DESIGN

Single-center, retrospective case cohort series between elective RA-TLIF and ON-TLIF groups.

PATIENT SAMPLE

27 patients who underwent elective RA-TLIF and control group of 50 elective ON-TLIF.

OUTCOME MEASURES

Operative duration, length of inpatient stay, post-operative ambulation, rates of intra-operative and post-operative complications and inpatient costs.

METHODS

Patient demographics (age, gender, Charlson Co-morbidity Index (CCI), BMI), post-operative outcomes and inpatient costs were used in comparative analysis.

RESULTS

No significant differences were found in patient demographics, baseline CCI, operative duration, length of inpatient stay, and post-operative ambulation. Rates of intra-operative and post-operative complications were similar between the 2 groups (OR = 0.93, p = 0.112). Inpatient hospitalization costs were not significantly different between both groups.

CONCLUSION

RA-TLIF has shown similar cost-effectiveness and surgical outcomes in comparison with conventional ON-TLIF. While not present in this study, RA-TLIF is associated with a longer operative duration due to higher learning curve, set-up time and possible hardware/ software errors. Ultimately, more case numbers are required for the operating staff to overcome this learning curve to achieve optimal results. Spine surgical centers evaluating both techniques may consider either with confidence.

Transiliac-Transsacral Screw Fixation is Superior to Lumbopelvic Stabilization in the Treatment of Minimally Displaced Sacral H-/U-Type Fragility Fractures

Study DesignRetrospective Cohort Study.ObjectivesTo compare the outcomes and complications of transiliac-transsacral screw fixation (TIS) and lumbopelvic fixation (LPS), the 2 most common fixation methods for nondisplaced and minimally displaced H-/U- type sacral fragility fractures.MethodsMedical records of patients treated with TIS or LPS for nondisplaced and minimally displaced H-/U-type sacral fragility fractures at 2 level A trauma centers between 2012 and 2022 were analyzed. Postoperative low back pain and mobility levels were assessed as primary outcomes before discharge and at 6 weeks and 6 months postoperatively. Surgery time, blood loss, and surgical complication rates were assessed as secondary outcomes. Statistical analyses consisted of Fisher's exact tests for frequency distributions and Mann-Whitney-U tests and t-tests for group comparisons.Results52 patients undergoing TIS (mean age: 78 ± 9 years) and 36 patients undergoing LPS (74 ± 10 years) with no discrepancy in demographic parameters were identified. There were no differences in low back pain levels between the 2 groups before surgery, before discharge, at 6 weeks postoperatively, and at 6 months postoperatively (P > 0.05). There were no differences in mobility levels before surgery, before discharge, at 6 weeks postoperatively, and at 6 months postoperatively (P > 0.05). Duration of surgery was shorter after TIS (36 ± 13 min) compared to LPS (113 ± 31 min) (P < 0.0001). Intraoperative blood loss was lower for TIS (median <20 mL) compared to LPS (median 125 mL) (P < 0.0001). Postoperative radiculopathy was less frequent after TIS (n = 1) compared to LPS (n = 3) (P > 0.05). Median length of stay was shorter after TIS (11 days) compared to LPS (14 days) (P < 0.05). Rates of reoperations directly related to the index surgery were lower after TIS (n = 2) compared to LPS (n = 10) (P < 0.01). Implant failures were observed only after LPS (n = 1).ConclusionPatients with nondisplaced and minimally displaced H-/U- type sacral fragility fractures may preferably be treated using TIS, as it is equivalent to LPS in terms of low back pain reduction and restoration of mobility, but allows for shorter operative time, less blood loss and lower reoperation rates. Prospective randomized studies should be conducted to substantiate our findings and develop distinct treatment recommendations.

The Early Clinical and Radiographic Outcomes of Robotic-Assisted Midline Lumbar Interbody Fusion (MIDLIF) With Expandable Interbody Spacers: A Case Series

OBJECTIVE

To assess the early clinical and radiological outcomes of the midline lumbar interbody fusion (MIDLIF) approach with the use of robotic assistance and expandable spacers.

METHODS

A retrospective case series was performed on patients who underwent MIDLIF procedures for the treatment of degenerative spinal diseases, with a minimum of three months postoperative follow-up. Demographic (age, gender, body mass index [BMI], comorbidities, and diagnoses), surgical data (operative time, blood loss, hospital stay, intraoperative complications), patient-reported outcomes (PROs) (visual analogue scale [VAS] back pain and disability (Oswestry disability index [ODI]), and radiographic data were collected.

RESULTS

In total, 42 patients were included, with an average age of 53.6 years and a BMI of 28 kg/m². Surgical data showed the mean total operative time was 98.8 minutes, and the mean blood loss was 17.1 mL with no intraoperative complications. At three-month follow-up, all mean PROs showed statistically significant improvement (p<0.05) when compared with baseline. VAS back pain improved from 7.5 (standard deviation (stdev) 7.5±0.7) preoperatively to 3.0 (stdev 1.0) at three months postoperative, while ODI improved from 58.7 (stdev 7.2) to 26.3 (stdev 10.3) at the same time points. Radiographic data showed that using robotic assistance for planning and placing cortical screws yielded high accuracy, as evidenced by a mean tip deviation of 1.2 mm (stdev 0.6 mm), mean tail deviation of 1.1 mm (stdev 0.4 mm) and a mean angular offset of 1.4 mm (stdev 0.7). Two (4.8%) patients had postoperative complications at three-month follow-up, including a wound infection and one report of wound dehiscence.

CONCLUSION

MIDLIF is an efficient, reproducible surgical procedure with a low complication rate that resulted in significant improvements in early PROs. Robotic assistance for planning and placing cortical screws in MIDLIF was highly accurate. These initial findings suggest that using robotic assistance adds value to MIDLIF procedures and is a viable alternative to traditional posterior fusion procedures.

Evolution of Robotic Spine Surgery Technologies

Robotic-assisted spine surgery has significantly advanced surgical precision and safety. This is particularly pertinent in minimally invasive spine surgeries that rely on imaging and technologies for visualization and the ability to accomplish surgical goals through smaller surgical corridors. The ability to preoperatively plan and then place pedicle screws across a wide range of applications has reduced the difficulty of even complex surgeries that once may have been considered prohibitive for minimally invasive approaches. While challenges and limitations remain, ongoing research and development aim to address these to continually expand the benefits of robotic-assisted spine surgery.

Does Robotic Spine Surgery Add Value to Surgical Practice over Navigation-Based Systems? A Study on Operating Room Efficiency

Background and Objectives: Spine surgery has undergone significant advancements, particularly with regard to robotic systems that enhance surgical techniques and improve patient outcomes. As these technologies become increasingly integrated into surgical practice, it is essential to evaluate their added value and cost savings. Hence, this study compared robot-assisted and navigation-based spine surgery, focusing on surgical efficiency. Materials and Methods: We conducted a single-center, retrospective cohort study of patients undergoing single- and double-level transforaminal lumbar interbody fusion (TLIF) and oblique lumbar interbody fusion (OLIF) surgeries. Patients were divided into two groups: those who had robot-assisted and navigation-based surgeries, stratified by surgery type (TLIF or OLIF) and fusion levels (one or two). A comparative analysis of factors related to surgical efficiency, including operative duration, blood loss, and length of hospital stay, was conducted. Results: Our results showed a statistically significant reduction in operative duration for robot-assisted one- and two-level OLIF cases, with average time savings of 50 and 62 min, respectively, compared to navigation-based surgery. These time savings translated to an estimated cost reduction of SGD 1500 for the hospital for each patient for a two-level OLIF procedure and could be higher as the number of operated levels increase. Conclusions: These results indicated that robot-assisted spine surgery offers superior surgical efficiency and cost savings, particularly with increased numbers of surgical levels. As robotic technologies evolve, their integration into spine surgery is justified, promising improved patient outcomes and cost-effectiveness.

Robot-assisted pedicle screw insertion versus navigation-based and freehand techniques for posterior spinal fusion in scoliosis: a systematic review and meta-analysis

PURPOSE

The role of robotics in spine surgery remains controversial, especially for scoliosis correction surgery. This study aims to assess the safety and efficacy of robotic-assisted (RA) surgery specifically for scoliosis surgery by comparing RA to both navigation systems (NS) and conventional freehand techniques (CF).

METHODS

As per the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines, a systematic review and meta-analysis were conducted via an electronic search of the following databases: MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL). All papers comparing RA to either NS or CF for posterior spinal fusion in scoliosis were included. Fixed and random effects models of analysis were utilised based on analysis heterogeneity.

RESULTS

10 observational studies were included in total. RA had significantly greater odds of accurate pedicle screw placement relative to both NS (OR = 2.02, CI = 1.52-2.67, p < 0.00001) and CF (OR = 3.06, CI = 1.79-5.23, p < 0.00001). The downside of RA was the significantly greater operation duration relative to NS (MD = 10.74, CI = 3.52-17.97, p = 0.004) and CF (MD = 40.27, CI = 20.90, p < 0.0001). Perioperative outcomes including estimated blood loss, radiation exposure, length of hospital stay, cobb angle correction rate, postoperative SRS score, VAS pain score, JOA score, as well as rates of neurological injury and revision surgery, were comparable between the groups (p > 0.05).

CONCLUSION

RA offers significantly greater pedicle screw placement accuracy relative to NS and CF, however, surgery can take longer. In terms of perioperative outcomes, all three techniques are comparable.

Advancing robot-guided techniques in lumbar spine surgery: a systematic review and meta-analysis

BACKGROUND

Lumbar spine surgery is a crucial intervention for addressing spinal injuries or conditions affecting the spine, often involving lumbar fusion through pedicle screw (PS) insertion. The precision of PS placement is pivotal in orthopedic surgery. This systematic review compares the accuracy of robot-guided (RG) surgery with free-hand fluoroscopy-guided (FFG), free-hand without fluoroscopy-guided (FHG), and computed tomography image-guided (CTG) techniques for PS insertion.

METHODS

A systematic search of various databases from 1 January 2013 to 30 December 2023 was conducted following PRISMA guidelines. Primary outcomes, including PS insertion accuracy and breach rate, were analyzed using a random-effects model. Risk of bias was assessed using the Newcastle-Ottawa Scale.

RESULTS

The overall accuracy of PS insertion using RG, based on 37 studies involving 3,837 patients and 22,117 PS, is 97.9%, with a breach rate of 0.021. RG demonstrated superior accuracy compared to FHG and CTG, with breach rates of 3.4 and 0.015 respectively for RG versus FHG, and 3.8 and 0.026 for RG versus CTG. Additionally, RG was associated with reduced mean estimated blood loss compared to CTG, indicating improved safety.

CONCLUSIONS

The RG is associated with enhanced accuracy of PS insertion and reduced breach rates over other methods. However, additional randomized controlled trials comparing these modalities are needed for further validation.

PROSPERO REGISTRATION

CRD42023483997.

Safety of robotic-assisted screw placement for spine surgery: Experience from the initial 125 cases

BACKGROUND

The present study aimed to evaluate the safety of robot-assisted screw placement in 125 cases after introducing a spinal robotics system and to identify the situations where deviation was likely to occur.

METHODS

The subjects were 125 consecutive patients who underwent robotic-assisted screw placement using a spinal robotics system (Mazor X Stealth Edition, Medtronic) from April 2021 to January 2023. The 1048 screws placed with robotic assistance were evaluated. We investigated intraoperative adverse events of the robotics system and complications occurring within 30 days after surgery. We evaluated screw accuracy and deviation and compared them for vertebral levels, screw insertion methods (open traditional pedicle screw [Open-PS], cortical bone trajectory screw [CBT], percutaneous pedicle screw [PPS], and S2 alar iliac screw [S2AIS]), diagnosis, and phases of surgical cases.

RESULTS

The deviation rate of robotic-assisted screw placement for spine surgery was 2.2%. Complications were reoperation due to implant-related neurological deficit in 0.8% and surgical site infection in 0.8%. There was significant difference in the deviation rate between vertebral levels. The deviation rate of the T1-T4 level was high at 10.0%. There was significant difference in the deviation rate between Open-PS, CBT, PPS, and S2AIS. The PPSs had a high deviation rate of 10.3%. The deviation rates were not significantly different between patients with and without deformity. The deviation rate did not change depending on the experience of surgical cases, and the deviation rate was favorable from the onset.

CONCLUSION

Although the robotic-assisted screw placement was safe, we should be extra vigilant when placing screws in the upper thoracic region (deviation rate 10.0%) and when using PPSs (deviation rate 10.3%).

Preoperative Robotics Planning Facilitates Complex Construct Design in Robot-Assisted Minimally Invasive Adult Spinal Deformity Surgery-A Preliminary Experience

(1) Background: The correction of adult spinal deformity (ASD) can require long, complex constructs with multiple rods which traverse important biomechanical levels to achieve multi-pelvic fixation. Minimally invasive (MIS) placement of these constructs has historically been difficult. Advanced technologies such as spinal robotics platforms can facilitate the design and placement of these constructs and further enable these surgical approaches in MIS deformity surgery. (2) Methods: A retrospective study was performed on a series of ASD patients undergoing MIS deformity correction with ≥eight fusion levels to the lower thoracic spine with preoperative robotic construct planning and robot-assisted pedicle screw placement. (3) Results: There were 12 patients (10 female, mean age 68.6 years) with a diagnosis of either degenerative scoliosis (8 patients) or sagittal imbalance (4 patients). All underwent preoperative robotic planning to assist in MIS robot-assisted percutaneous or transfascial placement of pedicle and iliac screws with multiple-rod constructs. Mean operative values per patient were 9.9 levels instrumented (range 8-11), 3.9 interbody cages (range 2-6), 3.3 iliac fixation points (range 2-4), 3.3 rods (range 2-4), 18.7 screws (range 13-24), estimated blood loss 254 cc (range 150-350 cc), and operative time 347 min (range 242-442 min). All patients showed improvement in radiographic sagittal, and, if applicable, coronal parameters. Mean length of stay was 5.8 days with no ICU admissions. Ten patients ambulated on POD 1 or 2. Of 224 screws placed minimally invasively, four breaches were identified on intraoperative CT and repositioned (three lateral, one medial) for a robot-assisted screw accuracy of 98.2%. (4) Conclusions: Minimally invasive long-segment fixation for adult spinal deformity surgery has historically been considered laborious and technically intensive. Preoperative robotics planning facilitates the design and placement of even complex multi-rod multi-pelvic fixation for MIS deformity surgery.

Pedicle screw placement accuracy in robot-assisted versus image-guided freehand surgery of thoraco-lumbar spine (ROBARTHRODESE): study protocol for a single-centre randomized controlled trial

BACKGROUND

Robotic spinal surgery may result in better pedicle screw placement accuracy, and reduction in radiation exposure and length of stay, compared to freehand surgery. The purpose of this randomized controlled trial (RCT) is to compare screw placement accuracy of robot-assisted surgery with integrated 3D computer-assisted navigation versus freehand surgery with 2D fluoroscopy for arthrodesis of the thoraco-lumbar spine.

METHODS

This is a single-centre evaluator-blinded RCT with a 1:1 allocation ratio. Participants (n = 300) will be randomized into two groups, robot-assisted (Mazor X Stealth Edition) versus freehand, after stratification based on the planned number of pedicle screws needed for surgery. The primary outcome is the proportion of pedicle screws placed with grade A accuracy (Gertzbein-Robbins classification) on postoperative computed tomography images. The secondary outcomes are intervention time, operation room occupancy time, length of stay, estimated blood loss, surgeon's radiation exposure, screw fracture/loosening, superior-level facet joint violation, complication rate, reoperation rate on the same level or one level above, functional and clinical outcomes (Oswestry Disability Index, pain, Hospital Anxiety and Depression Scale, sensory and motor status) and cost-utility analysis.

DISCUSSION

This RCT will provide insight into whether robot-assisted surgery with the newest generation spinal robot yields better pedicle screw placement accuracy than freehand surgery. Potential benefits of robot-assisted surgery include lower complication and revision rates, shorter length of stay, lower radiation exposure and reduction of economic cost of the overall care.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05553028. Registered on September 23, 2022.

Utility of a Navigated High-Speed Drill in Robotic-Assisted Screw Placement for Spine Surgery

Purpose To elucidate the utility of a navigated high-speed drill used after the version upgrade in surgeries assisted by a spinal robotics system. Methods The subjects were 166 patients who underwent screw placement using a spinal robotics system between April 2021 to July 2023. A significant change during the study was the introduction of a navigated high-speed drill in 80 post-upgrade cases, aimed at improving drilling accuracy. Screw accuracy was analyzed using the Gertzbein and Robbins classification on postoperative CT scans. Screws placed before (pre-upgrade group: 718 screws in 86 cases) and after the system upgrade (post-upgrade group: 747 screws in 80 cases) were compared in terms of perfect accuracy and deviation rates. Results There were no significant differences in demographics or surgical details between the two groups. No significant differences were observed in the overall perfect accuracy rate and deviation rate (2.4% pre-upgrade vs. 2.0% post-upgrade) between the two groups. For the percutaneous pedicle screw (PPS), the perfect accuracy rate was significantly higher, and the deviation rate was significantly lower in the post-upgrade group (26.1% pre-upgrade vs. 4.4% post-upgrade). Notably, the post-upgrade group achieved 100% perfect accuracy and 0% deviation for the cortical bone trajectory screw (CBT) technique. Conclusions The introduction of the navigated high-speed drill did not significantly alter the overall perfect accuracy or deviation rates for robotic-assisted screw placement. However, its use did demonstrate improved outcomes in specific techniques such as PPS and CBT, indicating its potential value in addressing skiving in robotic-assisted minimally invasive surgeries.

Da Vinci Meets Globus Excelsius GPS: A Totally Robotic Minimally Invasive Anterior and Posterior Lumbar Fusion

BACKGROUND

Minimally invasive approaches to the spine via anterior and posterior approaches have been increasing in popularity, culminating in the development of robot-assisted spinal fusions. The da Vinci surgical robot has been used for anterior lumbar interbody fusion (ALIF), with promising results. Similarly, multiple spinal robots have been developed to assist placement of posterior pedicle screws. However, no previous cases have reported on using robots for both anterior and posterior fixation in a single surgery. We present a technical note on the first reported case of a totally robotic minimally invasive anterior and posterior lumbar fusion and instrumentation.

METHODS

A 65-year-old man with chronic low back pain and left greater than right lower extremity radiculopathy was found to have grade 1 spondylolisthesis at L5/S1 that worsened on standing upright. He underwent ALIF using a da Vinci robotic approach, followed by percutaneous posterior instrumented fusion with the Globus Excelsius GPS robot.

RESULTS

The patient did well postoperatively, with improvement of back and leg pain at 3 months follow-up. Radiography confirmed appropriate placement of the interbody cage and pedicle screws.

CONCLUSIONS

All-robotic placement of both ALIF and posterior lumbar pedicle fixation may be safe, feasible, and efficacious.