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

Deviation from preoperative planning and pedicle screw accuracy in navigated and robotic spinal fusion: a systematic review

PURPOSE

Image-guided navigation and robotic systems have been introduced in spinal surgery to increase the accuracy of pedicle screws placement and reduce the rate of complications. The objective of this study is to evaluate the different final screw deviation from pre-operative planning and the associated pedicle screw accuracy in spinal fusion surgery assisted by image-guided navigation or robotic systems.

METHODS

The systematic literature search was executed using PubMed-Medline, Cochrane Central, and Scopus on 30 April 2023. Studies that explored the deviation between final position and preoperative planning of pedicle screws assisted by image-guide navigation or robotic system were included. The data extracted were surgical approach, surgical aid, number of screws evaluated, spinal levels, accuracy and deviation of screws. The quality of the studies was assessed using the revised Cochrane risk-of-bias tool for randomized trials (RoB 2) or the methodological index for non-randomized studies (MINORS) score.

RESULTS

This review included 15 studies, of which 5 used navigation and 10 robotic system. The studies involved 1487 patients, with the evaluation of a total of 7274 pedicle screws, with an assessment of planning and final position. The different methodologies to calculate the deviation include angular deviations in the axial and sagittal plane, 3D angular deviation, and tip and entry point deviation. Regarding screw accuracy, 98.15% of the screws were grade A or B, and 1.85% as category C or D.

CONCLUSION

Although preoperative planning allows the surgeon to plan the final position of the screw most appropriately, mild deviations from it do not seem to excessively influence the accuracy of the spinal fusion.

A surgeon-controlled mode of robotic assistance with posterolateral approach helps achieve highly medialized cervical pedicle screw placement to avoid vertebral artery injury

PURPOSE

The small pedicle widths, the thin lateral cortical shell next to the vertebral artery (VA), and the strongly tilted pedicle axis anteromedially narrow the safety margin for cervical pedicle screw (CPS) placement against vertebral artery (VA) injury. We have studied whether the minimally invasive surgery (MIS) of a posterolateral approach with a table-mounted, surgeon-controlled mode of robotic assistance (group R) improves the VA safety compared to C-arm fluoroscopy-guided conventional open technique (group F).

METHODS

Group R consisted of 165 screws in 37 patients and group F, 199 screws in 52 patients. The two groups covered a broad range of vertebral levels from C2 to C7 with comparable distribution (p = 0.0512) for treating a similar variety of diseases (p = 0.6958).

RESULTS

Group R, compared with group F, showed a greater lateral-to-medial CPS inclination (p ≤ 0.0004) that even exceeded the obliquity of corresponding pedicle axis, leading to a higher rate of acceptable CPS placement (93.4% vs. 85.4%; p = 0.0164) with a lower rate of lateral breach (1.2% vs. 10.1%; p = 0.0004).

CONCLUSION

For CPS placement, robot-assisted MIS obviously eliminates morbidity-prone soft-tissue dissection, radiation exposure to the surgical team, and human manual errors. The current study revealed its additional benefit of better safety against VA injury by allowing us to place CPS with a steep lateral-to-medial angulation owing to (1) a lack of counter pressure from the paravertebral muscles and (2) minimizing a navigation pitfall of untracked pressure-induced vertebral rotation.

[Navigated and minimally invasive screw osteosynthesis of a talus fracture]

OBJECTIVE OF SURGERY

The aim of this surgery is to safeguard the multifragmentary and nondisplaced talus fracture (body and neck) against secondary dislocation in a navigated and minimally invasive manner using screw osteosynthesis.

INDICATIONS

Due to the young age of the patient in the presented case and the risk of a possible secondary dislocation, the decision was made in favor of surgical treatment.

CONTRAINDICATIONS

Soft tissue swelling, wound infections and allergies to the osteosynthesis material.

SURGICAL TECHNIQUE

The video is available online (in English) and shows the individual surgical steps in detail. Preoperative computed tomography (CT) imaging and screw planning. Attachment of the reference array. 1) Cone beam CT (CBCT) scan, image fusion and fusion control. Planning of the minimally invasive skin incisions. Skin incision, navigated drilling and insertion of the K‑wires. 2) CBCT scan and position check of the K‑wires, fine adjustment if necessary. Insertion of the screws. 3) CBCT scan with subsequent position check of the screws, retightening of the screws if necessary. Performed in the Robotic Suite (Brainlab, Munich, Germany) using the following elements: navigation unit curve navigation system, movable robotic 3D CBCT, "Loop-X" and wall monitor "BUZZ".

FOLLOW-UP

Postoperative X‑ray and CT to control the position of the implants. Partial weight-bearing of the foot with 10 kg sole contact for 6 weeks. Physiotherapy with active and passive joint mobilization. Thrombosis prophylaxis with enoxaparin sodium. Optional implant removal after approximately 1 year.

EVIDENCE

Navigated operations are routine, so far mainly in the area of the spine. This article shows that navigated extremity surgery can be successfully performed in hybrid operating theaters.

Precision and effort in robot-assisted placement of pedicle screws compared to standard surgical navigation

Aim was to compare image-guided navigation with a robot-assisted solution for performing MISS regarding precision, required time and subjective aspects. 90 pedicles were instrumented on two torsos, half with navigation, half robot-assisted. Precision analysis between both solutions didn't show a significant difference. Time measurement showed a significantly longer duration per wire for the robot-arm on the first torso and a not significant longer duration on the second torso, where a significant reduction in the mean duration was shown. There was no significant difference in the subjective impressions comparing navigation and robot except the possibility to change the procedure. Precision of both methods is suitable for clinical use. A time advantage using the robot-arm couldn't be demonstrated in the present study. A significant learning curve was shown, so a reduction in the longer duration on the robot can be expected. Further studies in clinical use are necessary.

Hybrid-3D robotic suite in spine and trauma surgery - experiences in 210 patients

BACKGROUND

In modern Hybrid ORs, the synergies of navigation and robotics are assumed to contribute to the optimisation of the treatment in trauma, orthopaedic and spine surgery. Despite promising evidence in the area of navigation and robotics, previous publications have not definitively proven the potential benefits. Therefore, the aim of this retrospective study was to evaluate the potential benefit and clinical outcome of patients treated in a fully equipped 3D-Navigation Hybrid OR.

METHODS

Prospective data was collected (March 2022- March 2024) after implementation of a fully equipped 3D-Navigation Hybrid OR ("Robotic Suite") in the authors level 1 trauma centre. The OR includes a navigation unit, a cone beam CT (CBCT), a robotic arm and mixed reality glasses. Surgeries with different indications of the spine, the pelvis (pelvic ring and acetabulum) and the extremities were performed. Spinal and non-spinal screws were inserted. The collected data was analysed retrospectively. Pedicle screw accuracy was graded according to the Gertzbein and Robbins (GR) classification.

RESULTS

A total of n = 210 patients (118 m:92f) were treated in our 3D-Navigation Hybrid OR, with 1171 screws inserted. Among these patients, 23 patients (11.0%) arrived at the hospital via the trauma room with an average Injury Severity Score (ISS) of 25.7. There were 1035 (88.4%) spinal screws inserted at an accuracy rate of 98.7% (CI95%: 98.1-99.4%; 911 GR-A & 111 GR-B screws). The number of non-spinal screws were 136 (11.6%) with an accuracy rate of 99.3% (CI95%: 97.8-100.0%; 135 correctly placed screws). This resulted in an overall accuracy rate of 98.8% (CI95%: 98.2-99.4%). The robotic arm was used in 152 cases (72.4%), minimally invasive surgery (MIS) was performed in 139 cases (66.2%) and wound infection occurred in 4 cases (1,9%). Overall, no revisions were needed.

CONCLUSION

By extending the scope of application, this study showed that interventions in a fully equipped 3D-Navigation Hybrid OR can be successfully performed not only on the spine, but also on the pelvis and extremities. In trauma, orthopaedics and spinal surgery, navigation and robotics can be used to perform operations with a high degree of precision, increased safety, reduced radiation exposure for the OR-team and a very low complication rate.

Fully automated determination of robotic pedicle screw accuracy and precision utilizing computer vision algorithms

Historically, pedicle screw accuracy measurements have relied on CT and expert visual assessment of the position of pedicle screws relative to preoperative plans. Proper pedicle screw placement is necessary to avoid complications, cost and morbidity of revision procedures. The aim of this study was to determine accuracy and precision of pedicle screw insertion via a novel computer vision algorithm using preoperative and postoperative computed tomography (CT) scans. Three cadaveric specimens were utilized. Screw placement planning on preoperative CT was performed according to standard clinical practice. Two experienced surgeons performed bilateral T2-L4 instrumentation using robotic-assisted navigation. Postoperative CT scans of the instrumented levels were obtained. Automated segmentation and computer vision techniques were employed to align each preoperative vertebra with its postoperative counterpart and then compare screw positions along all three axes. Registration accuracy was assessed by preoperatively embedding spherical markers (tantalum beads) to measure discrepancies in landmark alignment. Eighty-eight pedicle screws were placed in 3 cadavers' spines. Automated registrations between pre- and postoperative CT achieved sub-voxel accuracy. For the screw tip and tail, the mean three-dimensional errors were 1.67 mm and 1.78 mm, respectively. Mean angular deviation of screw axes from plan was 1.58°. For screw mid-pedicular accuracy, mean absolute error in the medial-lateral and superior-inferior directions were 0.75 mm and 0.60 mm, respectively. This study introduces automated algorithms for determining accuracy and precision of planned pedicle screws. Our accuracy outcomes are comparable or superior to recent robotic-assisted in vivo and cadaver studies. This computerized workflow establishes a standardized protocol for assessing pedicle screw placement accuracy and precision and provides detailed 3D translational and angular accuracy and precision for baseline comparison.

Navigation-Guided/Robot-Assisted Spinal Surgery: A Review Article

The development of minimally invasive spinal surgery utilizing navigation and robotics has significantly improved the feasibility, accuracy, and efficiency of this surgery. In particular, these methods provide improved accuracy of pedicle screw placement, reduced radiation exposure, and shortened learning curves for surgeons. However, research on the clinical outcomes and cost-effectiveness of navigation and robot-assisted spinal surgery is still in its infancy. Therefore, there is limited available evidence and this makes it difficult to draw definitive conclusions regarding the long-term benefits of these technologies. In this review article, we provide a summary of the current navigation and robotic spinal surgery systems. We concluded that despite the progress that has been made in recent years, and the clear advantages these methods can provide in terms of clinical outcomes and shortened learning curves, cost-effectiveness remains an issue. Therefore, future studies are required to consider training costs, variable initial expenses, maintenance and service fees, and operating costs of these advanced platforms so that they are feasible for implementation in standard clinical practice.

[Robot-assisted pedicle screw placement]

OBJECTIVE

Pedicle screw-based posterior instrumentation of the spine.

INDICATIONS

Instability of the spine due to trauma, infection, degenerative spinal disease or tumor.

CONTRAINDICATIONS

None.

SURGICAL TECHNIQUE

Robot-assisted navigated pedicle screw placement.

POSTOPERATIVE MANAGEMENT

Early functional mobilization starting on the first postoperative day.

RESULTS

A study by Lee et al. analyzed the clinical application of the system Mazor X Stealth Edition (Medtronic Navigation, Louisville, CO, USA; Medtronic Spine, Memphis, TN, USA) in 186 cases with a total of 1445 pedicle screws [1]. Correct screw positioning was achieved in 1432 pedicle screws (99.1%); six pedicle screws (0.4%) were revised intraoperatively. The mean duration of pedicle screw placement was 6.1 ± 2.3 min. Pojskić et al. published a case series regarding the application of the system Cirq (Brainlab, Munich, Germany) in 13 cases with a total number of 70 pedicle screws implanted [2]. Intraoperative imaging showed screw positioning according to the Gertzbein Robbins classification (GR) category A in 65 screws (92.9%) and GR B in one screw (1.4%). Screw positioning GR D with intraoperative revision was reported in two screws (2.9%). Mean duration of pedicle screw placement was 08:27 ± 06:54 min.

Advances in robotics and pediatric spine surgery

PURPOSE OF REVIEW

Robotic-assisted surgical navigation for placement of pedicle screws is one of the most recent technological advancements in spine surgery. Excellent accuracy and reliability results have been documented in the adult population, but adoption of robotic surgical navigation is uncommon in pediatric spinal deformity surgery. Pediatric spinal anatomy and the specific pediatric pathologies present unique challenges to adoption of robotic assisted spinal deformity workflows. The purpose of this article is to review the safety, accuracy and learning curve data for pediatric robotic-assisted surgical navigation as well as to identify "best use" cases and technical tips.

RECENT FINDINGS

Robotic navigation has been demonstrated as a safe, accurate and reliable method to place pedicle screws in pediatric patients with a moderate learning curve. There are no prospective studies comparing robotically assisted pedicle screw placement with other techniques for screw placement, however several recent studies in the pediatric literature have demonstrated high accuracy and safety as well as high reliability. In addition to placement of pediatric pedicle screws in the thoracic and lumbar spine, successful and safe placement of screws in the pelvis and sacrum have also been reported with reported advantages over other techniques in the setting of high-grade spondylolisthesis as well as pelvic fixation utilizing S2-alar iliac (S2AI) screws.

SUMMARY

Early studies have demonstrated that robotically assisted surgical navigation for pedicle screws and pelvic fixation for S2AI screws is safe, accurate, and reliable in the pediatric population with a moderate learning curve.

Development and Clinical Trial of a New Orthopedic Surgical Robot for Positioning and Navigation

Robot-assisted orthopedic surgery has great application prospects, and the accuracy of the robot is the key to its overall performance. The aim of this study was to develop a new orthopedic surgical robot to assist in spinal surgeries and to compare its feasibility and accuracy with the existing orthopedic robot. A new type of high-precision orthopedic surgical robot (Tuoshou) was developed. A multicenter, randomized controlled trial was carried out to compare the Tuoshou with the TiRobot (TINAVI Medical Technologies Co., Ltd., Beijing) to evaluate the accuracy and safety of their navigation and positioning. A total of 112 patients were randomized, and 108 patients completed the study. The position deviation of the Kirschner wire placement in the Tuoshou group was smaller than that in the TiRobot group (p = 0.014). The Tuoshou group was better than the TiRobot group in terms of the pedicle screw insertion accuracy (p = 0.016) and entry point deviation (p < 0.001). No differences were observed in endpoint deviation (p = 0.170), axial deviation (p = 0.170), sagittal deviation (p = 0.324), and spatial deviation (p = 0.299). There was no difference in security indicators. The new orthopedic surgical robot was highly accurate and optimized for clinical practice, making it suitable for clinical application.

First Clinical Experience with a Novel 3D C-Arm-Based System for Navigated Percutaneous Thoracolumbar Pedicle Screw Placement

Background and Objectives: Navigated pedicle screw placement is becoming increasingly popular, as it has been shown to reduce the rate of screw misplacement. We present our intraoperative workflow and initial experience in terms of safety, efficiency, and clinical feasibility with a novel system for a 3D C-arm cone beam computed-tomography-based navigation of thoracolumbar pedicle screws. Materials and Methods: The first 20 consecutive cases of C-arm cone beam computed-tomography-based percutaneous pedicle screw placement using a novel navigation system were included in this study. Procedural data including screw placement time and patient radiation dose were prospectively collected. Final pedicle screw accuracy was assessed using the Gertzbein–Robbins grading system. Results: In total, 156 screws were placed. The screw accuracy was 94.9%. All the pedicle breaches occurred on the lateral pedicle wall, and none caused clinical complications. On average, a time of 2:42 min was required to place a screw. The mean intraoperative patient radiation exposure was 7.46 mSv. Conclusions: In summary, the investigated combination of C-arm CBCT-based navigation proved to be easy to implement and highly reliable. It facilitates the accurate and efficient percutaneous placement of pedicle screws in the thoracolumbar spine. The careful use of intraoperative imaging maintains the intraoperative radiation exposure to the patient at a moderate level.

Comparison of three imaging and navigation systems regarding accuracy of pedicle screw placement in a sawbone model

3D-navigated pedicle screw placement is increasingly performed as the accuracy has been shown to be considerably higher compared to fluoroscopy-guidance. While different imaging and navigation devices can be used, there are few studies comparing these under similar conditions. Thus, the objective of this study was to compare the accuracy of two combinations most used in the literature for spinal navigation and a recently approved combination of imaging device and navigation system. With each combination of imaging system and navigation interface, 160 navigated screws were placed percutaneously in spine levels T11-S1 in ten artificial spine models. 470 screws were included in the final evaluation. Two blinded observers classified screw placement according to the Gertzbein Robbins grading system. Grades A and B were considered acceptable and Grades C-E unacceptable. Weighted kappa was used to calculate reliability between the observers. Mean accuracy was 94.9% (149/157) for iCT/Curve, 97.5% (154/158) for C-arm CBCT/Pulse and 89.0% for CBCT/StealthStation (138/155). The differences between the different combinations were not statistically significant except for the comparison of C-arm CBCT/Pulse and CBCT/StealthStation (p = 0.003). Relevant perforations of the medial pedicle wall were only seen in the CBCT group. Weighted interrater reliability was found to be 0.896 for iCT, 0.424 for C-arm CBCT and 0.709 for CBCT. Under quasi-identical conditions, higher screw accuracy was achieved with the combinations iCT/Curve and C-arm CBCT/Pulse compared with CBCT/StealthStation. However, the exact reasons for the difference in accuracy remain unclear. Weighted interrater reliability for Gertzbein Robbins grading was moderate for C-arm CBCT, substantial for CBCT and almost perfect for iCT.

Robotic Spine Surgery: Past, Present, and Future

STUDY DESIGN

Systematic review.

OBJECTIVE

The aim of this review is to present an overview of robotic spine surgery (RSS) including its history, applications, limitations, and future directions.

SUMMARY OF BACKGROUND DATA

The first RSS platform received United States Food and Drug Administration approval in 2004. Since then, robotic-assisted placement of thoracolumbar pedicle screws has been extensively studied. More recently, expanded applications of RSS have been introduced and evaluated.

METHODS

A systematic search of the Cochrane, OVID-MEDLINE, and PubMed databases was performed for articles relevant to robotic spine surgery. Institutional review board approval was not needed.

RESULTS

The placement of thoracolumbar pedicle screws using RSS is safe and accurate and results in reduced radiation exposure for the surgeon and surgical team. Barriers to utilization exist including learning curve and large capital costs. Additional applications involving minimally invasive techniques, cervical pedicle screws, and deformity correction have emerged.

CONCLUSION

Interest in RSS continues to grow as the applications advance in parallel with image guidance systems and minimally invasive techniques.

IRB APPROVAL

N/A.

Association of robot-assisted techniques with the accuracy rates of pedicle screw placement: A network pooling analysis

BACKGROUND

Traditional paired meta-analyses have yielded inconsistent results for the safety and effectiveness of robotic-assisted pedicle screw placement due to the high heterogeneity within studies. This study evaluated the clinical effectiveness and safety of robotic-assisted pedicle screw placement.

METHODS

The Embase, PubMed, and Cochrane Library databases were searched with no language limitations from inception to Jan 4, 2022. Odds ratio (OR), mean difference (MD), and 95% confidence interval (CI) were used to report results. The main outcomes were accuracy of pedicle screw placement, proximal facet joint violation, and complications. The study protocol was published in PROSPERO (CRD42022301417).

FINDINGS

26 trials including 2046 participants evaluating robotic-assisted pedicle screw placement were included in this study. Our pooled results showed that Renaissance (OR 2.86; [95% CI 1.79 to 4.57]) and TiRobot (OR 3.10; [95% CI 2.19 to 4.40]) yielded higher rates of perfect pedicle screw insertion (Grades A) than the conventional freehand technique. Renaissance (OR 2.82; [95% CI 1.51 to 5.25]) and TiRobot (OR 4.58; [95% CI 2.65 to 7.89]) yielded higher rates of clinically acceptable pedicle screw insertion (Grades A+B). However, ROSA, SpineAssist, and Orthobot were not associated with higher perfect pedicle screw insertion and clinically acceptable pedicle screw insertion rates. Robot-assisted techniques were associated with low rates of proximal facet joint violation (OR 0.18; [95% CI 0.10 to 0.32]; I²:9.55%) and overall complications (OR 0.38; [95% CI 0.23 to 0.63]; I²:27.05%). Moreover, robot-assisted techniques were associated with lower radiation doses (MD -14.38; [95% CI -25.62 to -3.13]; I²:100.00%).

INTERPRETATION

Our findings suggest that only Renaissance and TiRobot systems are associated with high accuracy rates of pedicle screw placement. Robotic-assisted techniques hold great promise in spinal surgery due to their safety and effectiveness.

FUNDING

This work was supported by grants from the National Natural Science Foundation of China (No. 81871818), Tangdu Hospital Seed Talent Program (Fei-Long Wei) and Natural Science Basic Research Plan in Shaanxi Province of China (No.2019JM-265).