A robot-assisted surgical system using a force-image control method for pedicle screw insertion

Sensorless Based Haptic Feedback Integration In Robot-assisted Pedicle Screw Insertion For Lumbar Spine Surgery: A preliminary cadaveric study

Pedicle screw fixation is an essential surgical technique for addressing various spinal pathologies, including degenerative diseases, trauma, tumors, neoplasms, and infections. Despite its efficacy, the procedure poses significant challenges, notably the limited visibility of spinal anatomical landmarks and the consequent reliance on surgeon's hand-eye coordination. These challenges often result in inaccuracies and high radiation exposure due to the frequent use of fluoroscopy X-ray guidance. Addressing these concerns, this study introduces a novel approach to pedicle screw insertion by utilizing a robot-assisted system that incorporates sensorless based haptics incorporated 5-DOF surgical manipulation. This innovative system aims to minimize radiation exposure and reduce operating time while improving the surgeon's hand posture capabilities. The developed prototype, expected to be implemented using bilateral control, was tested through preliminary cadaveric experiments focused on the insertion of both percutaneous and open pedicle screws at the L4-L5 level of the lumbar spine. Validation of the Sensorless Haptic Feedback feature was an integral part of this study, aiming to enhance precision and safety. The results, confirmed by fluoroscopic x-ray images, demonstrated the successful placement of two percutaneous and two open pedicle screws, with average position and torque errors of 0.011 radians and 0.054 Nm for percutaneous screws, and 0.0116 radians and 0.0057 Nm for open screws, respectively. These findings underscore the potential of the sensorless haptic feedback in a robot-assisted pedicle screw insertion system to significantly reduce radiation exposure and improve surgical outcomes, marking a significant advancement in spinal surgery technology.

Impact of optical navigation variables on the accuracy of robot-assisted surgery: a study of the TIANJI Robot system

This study aims to explore factors related to optical navigation that interfere with the accuracy of robot-assisted surgery, specifically focusing on the TIANJI Robot system. A measurement model was created to assess the accuracy of the TIANJI Robot system in simulated screw placement. Deviation between actual and planned positions was measured using a three-coordinate machine. Various experiments were conducted to investigate the impact of different optical navigation factors on screw placement accuracy. Deviations were measured at different distances (ranging from 1.2 to 2.2 m) between the optical navigation stereo camera and the tracker, with each distance being tested 50 times. The distance between the optical camera and patient tracker was set at 1.4 m. Deviations were also measured at different angles between the camera and robot tracker, repeated over 25 times for each angle. Data were analyzed using mean and standard deviation, with line charts illustrating deviation changes based on distance and angle details. Within the range of the TIANJI Robot system's optical navigation (1.2-2.2 m), deviation increased as distance increased (χ2 = 479.107, P < 0.001). The robotic system demonstrated high and consistent accuracy (mean deviation: 0.332 mm ± 0.067 mm) when the relative angle between the optical camera and tracker was below 40°. The accuracy of the TIANJI Robot system was found to be influenced by relative distance and angle between the optical camera and tracker during screw placement procedures. Surgeons are recommended to set a relative distance of 1.4-1.5 m between the optical camera and patient tracker, with a relative angle below 40° when placing and adjusting optical tracking devices.

Spine Surgical Robotics: Current Status and Recent Clinical Applications

With the development of artificial intelligence and the further deepening of medical-engineering integration, spine surgical robot-assisted (RA) technique has made significant progress and its applicability in clinical practice is constantly expanding in recent years. In this review, we have systematically summarized the majority of literature related to spine surgical robots in the past decade, and not only classified robots accordingly, but also summarized the latest research progress in RA technique for screw placement such as cervical, thoracic, and lumbar pedicle screws, cortical bone trajectory screws, cervical lateral mass screws, and S2 sacroiliac screws; guiding targeted puncture and placement of endoscope via the intervertebral foramen; complete resection of spinal tumor tissue; and decompressive laminectomy. In addition, this report also provides a detailed evaluation of RA technique's advantages and disadvantages, and clarifies the accuracy, safety, and practicality of RA technique. We consider that this review can help clinical physicians further understand and familiarize the current clinical application status of spine surgical robots, thereby promoting the continuous improvement and popularization of RA technique, and ultimately benefiting numerous patients.

State-of-the-Art of Non-Radiative, Non-Visual Spine Sensing with a Focus on Sensing Forces, Vibrations and Bioelectrical Properties: A Systematic Review

In the research field of robotic spine surgery, there is a big upcoming momentum for surgeon-like autonomous behaviour and surgical accuracy in robotics which goes beyond the standard engineering notions such as geometric precision. The objective of this review is to present an overview of the state of the art in non-visual, non-radiative spine sensing for the enhancement of surgical techniques in robotic automation. It provides a vantage point that facilitates experimentation and guides new research projects to what has not been investigated or integrated in surgical robotics. Studies were identified, selected and processed according to the PRISMA guidelines. Relevant study characteristics that were searched for include the sensor type and measured feature, the surgical action, the tested sample, the method for data analysis and the system's accuracy of state identification. The 6DOF f/t sensor, the microphone and the electromyography probe were the most commonly used sensors in each category, respectively. The performance of the electromyography probe is unsatisfactory in terms of preventing nerve damage as it can only signal after the nerve is disturbed. Feature thresholding and artificial neural networks were the most common decision algorithms for state identification. The fusion of different sensor data in the decision algorithm improved the accuracy of state identification.

Surgical Precision and Efficiency of a Novel Electromagnetic System Compared to a Robot-Assisted System in Percutaneous Pedicle Screw Placement of Endo-LIF

STUDY DESIGN

Retrospective database study.

OBJECTIVES

To compare the accuracy and safety of 2 types of a computer-assisted navigation system for percutaneous pedicle screw placement during endoscopic lumbar interbody fusion.

METHODS

From May 2019 to January 2020, data of 56 patients who underwent Endo-LIF with a robot-assisted system and with an electromagnetic navigation system were compared. The pedicles in all patients were subjected to postoperative CT scan to assess screw correction by measuring the perpendicular distance between the pedicle cortical wall and the screw surface. The registration and matching time, guide-wire insertion time, the entire surgery time, and X-ray exposure time were recorded.

RESULTS

In the robot-assisted group, 25 cases with 100 percutaneous pedicle screws were included, and the excellent and good rate was 95%. In the electromagnetic navigation group, 31 cases with 124 screws were included, and the excellent rate was 97.6%. There was no statistical difference between the two groups (P > 0.05). The registration time and the total time for the surgery also showed no statistical differences (P > 0.05). The main difference between the two groups was the guide-wire insertion time and the X-ray exposure time (P < 0.05).

CONCLUSIONS

Both electromagnetic navigation and robot-assisted are safe and efficient for percutaneous pedicle screw placement. Electromagnetic navigation system has obvious advantages over robot-assisted in terms of faster guide-wire placement and less X-ray exposure. Robot-assisted for percutaneous pedicle screw placement offers a preoperative planning system and a stable registration system, with obvious drawbacks of a strict training curve.

An improved path planning algorithm based on artificial potential field and primal-dual neural network for surgical robot

Safety and accuracy are essential for path planning in a surgical navigation system. In this paper, an improved path planning algorithm is proposed to increase the autonomous level of spine surgery robots for higher safety and accuracy. Firstly, the dynamic gravitational constant and piecewise repulsion function are adopted to improve the traditional Artificial Potential Field algorithm to solve the common issues of path planning, including local minimum, unable to reach the target near obstacles. To better control the pose of the end-effector in an operation space, the positions of the two endpoints of the end-effector are further constrained. Secondly, an improved Primal-Dual Neural Network with multiple constraints is proposed to minimize the joint angular velocity norm. The multiple constraints are formulated according to the planned path, the obstacle avoidance of the robot and the joint limits. Moreover, a real-time planned velocity scheme is applied to prevent the accumulation of position errors. The simulation results of the pedicle screw implantation demonstrate that the robot can find the collision-free trajectory and arrive at the target position in various complicated situations. More specifically, the error between two endpoints of the end-effector and the target pose is below 0.1 mm in reaching the surgical tool pose, while the maximum position error is around 0.05 mm when performing the planned path. Moreover, two experiments are conducted in the real-world to verify the proposed algorithm is effective in practice.

Posterior atlantoaxial internal fixation using Harms technique assisted by 3D-based navigation robot for treatment of atlantoaxial instability

Background

To evaluate the accuracy of screw placement using the TiRobot surgical robot in the Harms procedure and to assess the clinical outcomes of this technique.

Methods

This retrospective study included 21 patients with atlantoaxial instability treated by posterior atlantoaxial internal fixation (Harms procedure) using the TiRobot surgical robot between March 2016 and June 2021. The precision of screw placement, perioperative parameters and clinical outcomes were recorded. Screw placement was assessed based on intraoperative guiding pin accuracy measurements on intraoperative C-arm cone-beam computed tomography (CT) images using overlay technology and the incidence of screw encroachment identified on CT images.

Results

Among the 21 patients, the mean age was 44.8 years, and the causes of atlantoaxial instability were os odontoideum (n = 11), rheumatoid arthritis (n = 2), unknown pathogenesis (n = 3), and type II odontoid fracture (n = 5). A total of 82 screws were inserted with robotic assistance. From intraoperative guiding pin accuracy measurements, the average translational and angular deviations were 1.52 ± 0.35 mm (range 1.14–2.25 mm) and 2.25° ± 0.45° (range 1.73°–3.20º), respectively. Screw placement was graded as A for 80.5% of screws, B for 15.9%, and C for 3.7%. No complications related to screw misplacement were observed. After the 1-year follow-up, all patients with a neurological deficit experienced neurological improvement based on Nurick Myelopathy Scale scores, and all patients with preoperative neck pain reported improvement based on Visual Analog Scale scores.

Conclusions

Posterior atlantoaxial internal fixation using the Harms technique assisted by a 3D-based navigation robot is safe, accurate, and effective for treating atlantoaxial instability.

Comparison of the Accuracy and Safety of TiRobot-Assisted and Fluoroscopy-Assisted Percutaneous Pedicle Screw Placement for the Treatment of Thoracolumbar Fractures

OBJECTIVE

Studies have compared the safety and accuracy of robot-assisted techniques for inserting conventional open pedicle screws for spinal surgery. However, no relevant studies have confirmed that robot-assisted percutaneous screw placement is better than fluoroscopic percutaneous screw placement for the treatment of thoracolumbar fractures. This study compared the accuracy and safety of TiRobot-assisted percutaneous pedicle screw placement with those of the fluoroscopy-assisted percutaneous technique for the treatment of thoracolumbar fractures.

METHODS

This retrospective study included 126 patients with thoracolumbar fractures who underwent percutaneous pedicle screw placement. Sixty-five patients were treated with the TiRobot-assisted technique and 61 patients were treated with the fluoroscopy-assisted technique. Patient demographics, accuracy of screw placement (according to the Gertzbein and Robbins scale of grades A to E), screw insertion angle, radiation exposure, surgical time, intraoperative blood loss, length of hospital stay, incision length, hospital expenses, surgical site infection, and neurological injury of the TiRobot-assisted and fluoroscopy-assisted groups were compared using Student's t-test, Pearson χ² test, or Fisher's exact test.

RESULTS

A total of 729 screws were placed (TiRobot-assisted group: 374 screws; fluoroscopy-assisted group: 355 screws). In the TiRobot-assisted group, 82.8% of screws were optimally positioned (grade A); however, the placement grades of the remaining screws were categorized as grade B (13.3%), grade C (3.2%), and grade D (0.5%). In the fluoroscopy-assisted group, 66.7% of the screws were optimally positioned (grade A); however, the placement grades of the remaining screws were categorized as grade B (21.4%), grade C (7.6%), grade D (3.6%), and grade E (0.5%). The proportion of clinically acceptable screws (grade A or B) was greater in the TiRobot-assisted group than in the fluoroscopy-assisted group. Additionally, the TiRobot-assisted group had a significantly larger mean screw insertion angle (22.27° ± 5.48° vs 20.55° ± 5.15°), larger incision length (13.86 ± 1.24 cm vs 12.77 ± 1.43 cm), and higher hospital expenses (69061.55 ± 7166.60 yuan vs 59383.85 ± 5019.64 yuan) than the fluoroscopy-assisted group. There were no significant differences in the intraoperative blood loss, length of hospital stay, and rates of surgical site infection and neurological injury in both groups (p > 0.05). However, the TiRobot-assisted group had significantly better surgical times, radiation times, and radiation exposure than the fluoroscopy-assisted group (p < 0.05).

CONCLUSIONS

Percutaneous TiRobot-assisted pedicle screw placement is a safe, useful, and potentially more accurate alternative to the percutaneous fluoroscopy-assisted technique for treating thoracolumbar fractures.

Intraoperative tissue classification methods in orthopedic and neurological surgeries: A systematic review

Accurate tissue differentiation during orthopedic and neurological surgeries is critical, given that such surgeries involve operations on or in the vicinity of vital neurovascular structures and erroneous surgical maneuvers can lead to surgical complications. By now, the number of emerging technologies tackling the problem of intraoperative tissue classification methods is increasing. Therefore, this systematic review paper intends to give a general overview of existing technologies. The review was done based on the PRISMA principle and two databases: PubMed and IEEE Xplore. The screening process resulted in 60 full-text papers. The general characteristics of the methodology from extracted papers included data processing pipeline, machine learning methods if applicable, types of tissues that can be identified with them, phantom used to conduct the experiment, and evaluation results. This paper can be useful in identifying the problems in the current status of the state-of-the-art intraoperative tissue classification methods and designing new enhanced techniques.

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.

Can Robotic Spine Surgery Become the Standard of Care?

Concerns regarding traditional techniques led to the development of robotic systems to facilitate the safe and accurate placement of pedicle screws. The Mazor Spine Assist was the first robotic spine surgery (RSS) platform to receive US Food and Drug Administration approval in 2004. Since then, there has been a steady increase in the application of RSS with several additional iterations of the Mazor platform and other competing systems receiving approval. As the indications, potential benefits, and utilization of RSS continue to expand, the question naturally arises as to whether RSS will eventually become the standard of care for spine surgery. In this article, we review the available evidence and experience with RSS and discuss the potential for RSS to become the medical standard of care.

Human-Inspired Haptic Perception and Control in Robot-Assisted Milling Surgery

Bone milling is one of the most widely used and high-risk procedures in various types of surgeries, and it is important to be noted that the experienced surgeon can perform such an operation safely. The objective of this article is to enhance the safety of the robot-assisted milling operation with the inspiration of human haptic perception. The emergence, coding and perception of the human haptic are introduced. Following this, a single axis accelerometer that measures the vibration of the surgical power tool is mounted in the robot arm, and the recorded acceleration signal is encoded as parallel stream of binary data. The data are subsequently inputted to the Hopfield network so as to identify the milling state. Inspired by human inference procedure, the fuzzy logic controller is introduced to control the robot to track the desired state when performing bone milling operations. A real-time implementation of the proposed method on a digital signal processing is also described. The experimental results in milling porcine spines prove that the robot accurately discriminates different milling states even when the additive noise is serious, and the safe motion control of the robot is also realized.

The current state of navigation in robotic spine surgery

The advent and widespread adoption of pedicle screw instrumentation prompted the need for image guidance in spine surgery to improve accuracy and safety. Although the conventional method, fluoroscopy, is readily available and inexpensive, concerns regarding radiation exposure and the drive to provide better visual guidance spurred the development of computer-assisted navigation. Contemporaneously, a non-navigated robotic guidance platform was also introduced as a competing modality for pedicle screw placement. Although the robot could provide high precision trajectory guidance by restricting four of the six degrees of freedom (DOF), the lack of real-time depth control and high capital acquisition cost diminished its popularity, while computer-assisted navigation platforms became increasingly sophisticated and accepted. The recent integration of real-time 3D navigation with robotic platforms has resulted in a resurgence of interest in robotics in spine surgery with the recent introduction of numerous navigated robotic platforms. The currently available navigated robotic spine surgery platforms include the ROSA Spine Robot (Zimmer Biomet Robotics formerly Medtech SA, Montpellier, France), ExcelsiusGPS^® (Globus Medical, Inc., Audubon, PA, USA), Mazor X spine robot (Medtronic Navigation Louisville, CO; Medtronic Spine, Memphis, TN; formerly Mazor Robotics, Caesarea, Israel) and TiRobot (TINAVI Medical Technologies, Beijing, China). Here we provide an overview of these navigated spine robotic platforms, existing applications, and potential future avenues of implementation.

Comparison of Cranial Facet Joint Violation Rate and Four Other Clinical Indexes Between Robot-assisted and Freehand Pedicle Screw Placement in Spine Surgery: A Meta-analysis

STUDY DESIGN

A meta-analysis.

OBJECTIVE

Through meta-analysis, whether RA techniques are superior to conventional freehand (FH) techniques was determined in terms of cranial facet joint protection and four other clinical indexes, namely, the accuracy of pedicle screw placement, the number of surgical revision due to malposition, intraoperative radiation dose, and operative time.

SUMMARY OF BACKGROUND DATA

Cranial facet joint violation (FJV) is an important risk factor for adjacent segment degeneration. Some studies recommended the use of robot-assisted (RA) pedicle screw placement in reducing the rate of cranial FJV instead of conventional FH pedicle screw placement. However, the superiority of RA techniques to FH techniques remains controversial.

METHODS

A comprehensive search on PubMed, EMBASE, Cochrane, Web of Science, CNKI, and WanFang was conducted for the selection of potential eligible literature. The outcomes were evaluated in terms of odds ratio (OR) or standardized mean difference and corresponding 95% confidence interval (CI). The meta-analysis was conducted using RevMan 5.3. The subgroup analyses of the violation of the cranial facet joint and the accuracy of pedicle screw placement were performed on the basis of robot type.

RESULT

Three randomized controlled trials, two prospective cohort study, and one retrospective cohort study consisting of 783 patients and 2694 cranial pedicle screws were included in the meta-analysis. RA pedicle screw placement was associated with significantly fewer cranial FJVs than FH screw placement. Subgroup analyses showed that the Renaissance (OR = 0.19, 95% CI = 0.07-0.56) and TINAVI (OR = 0.19, 95% CI = 0.09-0.38) robots under RA techniques were associated with significantly fewer cranial FJVs than FH techniques. Furthermore, the RA techniques showed more accurate pedicle screw placement and lower intraoperative radiation dose, equivalent number of surgical revision due to malposition, but longer operative time than the FH techniques.

CONCLUSION

The RA (Renaissance and TINAVI) techniques are superior to conventional FH techniques in terms of protecting the cranial facet joint. RA techniques are accurate and safe in clinical application.

LEVEL OF EVIDENCE

2.

Accuracy of Pedicle Screw Placement and Four Other Clinical Outcomes of Robotic Guidance Technique versus Computer-Assisted Navigation in Thoracolumbar Surgery: A Meta-Analysis

BACKGROUND

Robotic guidance (RG) pedicle screw placement has been increasingly used to improve the rate of insertion accuracy. However, the superiority of the RG technique over computer-assisted navigation (CAN) remains debatable.

OBJECTIVE

To determine whether the Mazor RG technique is superior to CAN in terms of the rate of insertion accuracy and 4 other clinical indices, namely, intraoperative time, blood loss, complications and revision surgery caused by malposition.

METHODS

A search of PubMed, Embase, Cochrane, Web of Science, CNKI, and WanFang was conducted. We mainly aimed to evaluate the accuracy of pedicle screw placement between the Mazor RG and CAN techniques. The secondary objectives were intraoperative time, blood loss, complications, and revision surgery caused by malposition. The meta-analysis was conducted using the RevMan 5.3 and Stata 15.1 software.

RESULTS

A randomized controlled trial and 5 comparative cohort studies consisting of 529 patients and 4081 pedicle screws were included in this meta-analysis. The RG technique has a significantly higher accuracy than CAN in terms of optimal (odds ratio [OR], 2.26; 95% confidence interval [CI], 1.85-2.76; P < 0.01) and clinically acceptable (OR, 1.69; 95% CI, 1.22-2.34; P = 0.002) pedicle screw insertions. Furthermore, the RG technique showed significantly less blood loss (mean difference, -42.49; 95% CI, -78.38 to -6.61; P = 0.02) than did the CAN technique but has equivalent intraoperative time (mean difference, 0.75; 95% CI, -5.89 to 7.40; P = 0.82), complications (OR, 0.65; 95% CI, 0.32-1.33, P = 0.24), and revision surgery caused by malposition (OR, 0.46; 95% CI, 0.15-1.43, P = 0.18).

CONCLUSIONS

The Mazor RG technique is superior to CAN concerning the accuracy of pedicle screw placement. Thus, the Mazor RG technique is accurate and safe in clinical application.

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.

The Role of Minimal Access Surgery in the Treatment of Spinal Metastatic Tumors

STUDY DESIGN

Literature review.

OBJECTIVE

To provide an overview of the recent advances in minimal access surgery (MAS) for spinal metastases.

METHODS

Literature review.

RESULTS

Experience gained from MAS in the trauma, degenerative and deformity settings has paved the road for MAS techniques for spinal cancer. Current MAS techniques for the treatment of spinal metastases include percutaneous instrumentation, mini-open approaches for decompression and tumor resection with or without tubular/expandable retractors and thoracoscopy/endoscopy. Cancer care requires a multidisciplinary effort and adherence to treatment algorithms facilitates decision making, ultimately improving patient outcomes. Specific algorithms exist to help guide decisions for MAS for extradural spinal metastases. One major paradigm shift has been the implementation of percutaneous stabilization for treatment of neoplastic spinal instability. Percutaneous stabilization can be enhanced with cement augmentation for increased durability and pain palliation. Unlike osteoporotic fractures, kyphoplasty and vertebroplasty are known to be effective therapies for symptomatic pathologic compression fractures as supported by high level evidence. The integration of systemic body radiation therapy for spinal metastases has eliminated the need for aggressive tumor resection allowing implementation of MAS epidural tumor decompression via tubular or expandable retractors and preliminary data exist regarding laser interstitial thermal therapy and radiofrequency ablation for tumor control. Neuronavigation and robotic systems offer increased precision, facilitating the role of MAS for spinal metastases.

CONCLUSIONS

MAS has a significant role in the treatment of spinal metastases. This review highlights the current utilization of minimally invasive surgical strategies for treatment of spinal metastases.

Telerobotic Spinal Surgery Based on 5G Network: The First 12 Cases

Objective

The purpose of this study was to determine the efficacy and feasibility of 5th generation wireless systems (5G) telerobotic spinal surgery in our first 12 cases.

Methods

A total of 12 patients (5 males, 7 females; age, 23–71 years) with spinal disorders (4 thoracolumbar fractures, 6 lumbar spondylolisthesis, 2 lumbar stenosis) were treated with 5G telerobotic spinal surgery. Sixty-two pedicle screws were implanted.

Results

All patients had substantial relief from their symptoms. Screw placements were classified using Gertzbein-Robbins criteria. There were 59 grade A, 3 grade B. Mean operation time was 142.5 ± 46.7 minutes. Mean guiding wire insertion time was 41.3 ± 9.8 minutes. The deviation between the planned and actual positions was 0.76 ± 0.49 mm. No intraoperative adverse event was found.

Conclusion

5G remote robot-assisted spinal surgery is accurate and reliable. We conclude that 5G telerobotic spinal surgery is both efficacious and feasible for the management of spinal diseases with safety.

Improved Accuracy of Cervical Spinal Surgery With Robot-Assisted Screw Insertion: A Prospective, Randomized, Controlled Study

STUDY DESIGN

Prospective, randomized, controlled trial.

OBJECTIVE

To compare robot-assisted and conventional implantation techniques by evaluating the accuracy and safety of implanting screws in cervical vertebrae.

SUMMARY OF BACKGROUND DATA

Cervical spinal surgery is difficult and dangerous as screw misplacement might lead not only to decreased stability but also neurological, vascular, and visceral injuries. A new robot-assisted surgical procedure has been introduced to improve the accuracy of implant screw positioning.

METHODS

We randomly assigned 135 patients with newly diagnosed cervical spinal disease and who required screw fixation using either robot-assisted or conventional fluoroscopy-assisted cervical spinal surgery. The primary outcomes were the discrepancies between the planned trajectories and the actual screw positions.

RESULTS

Altogether, 127 patients underwent the assigned intervention (61 robot-assisted and 66 conventional fluoroscopy-assisted). The baseline characteristics including the screw types, were similar in the two groups. Altogether, 390 screws were planed and placed in the cervical vertebrae, and 94.9% were acceptable. The robot-assisted group had a better screw placement accuracy than the conventional fluoroscopy-assisted group with associated P values <0.001 (0.83 [0.44, 1.29] vs. 1.79 [1.41, 2.50] mm). The Gertzbein and Robbins scales also showed a significant difference between the two groups (P < 0.001). Furthermore, the robot-assisted group experienced significantly less blood loss during surgery than the conventional fluoroscopy-assisted group (200 [50, 375] vs. 350 [100, 500] mL; P = 0.002) and shorter length of stay after surgery (P = 0.021). These two groups did not differ significantly regarding the duration of the operation (P = 0.525). Neurological injury occurred in one case in the conventional fluoroscopy-assisted group.

CONCLUSION

The accuracy and clinical outcomes of cervical spinal surgery using the robot-assisted technique tended to be superior to those with the conventional fluoroscopy-assisted technique in this prospective, randomized, controlled trial.

LEVEL OF EVIDENCE

2.

Accuracy of Pedicle Screw Placement and Clinical Outcomes of Robot-assisted Technique Versus Conventional Freehand Technique in Spine Surgery From Nine Randomized Controlled Trials: A Meta-analysis

STUDY DESIGN

A meta-analysis.

OBJECTIVE

To investigate whether robot-assisted techniques are superior to conventional techniques in terms of the accuracy of pedicle screw placement and clinical indexes.

SUMMARY OF BACKGROUND DATA

Robot-assisted techniques are increasingly applied to spine surgery to reduce the rate of screw misplacement. However, controversy about the superiority of robot-assisted techniques over conventional freehand techniques remains.

METHODS

We conducted a comprehensive search of PubMed, EMBASE, and Cochrane Library for potentially eligible articles. The outcomes were evaluated in terms of risk ratio (RR) or standardized mean difference and the associated 95% confidence intervals (CIs). Meta-analysis was performed using the RevMan 5.3 software and subgroup analyses were performed based on the robot type for the accuracy of pedicle screw placement.

RESULTS

Nine randomized controlled trials with 696 patients were included in this meta-analysis. The results demonstrated that the robot-assisted technique was more accurate in pedicle screw placement than the freehand technique. Subgroup analyses showed that the TINAVI robot-assisted technique was more accurate in screw positions Grade A (RR, 1.10; 95% CI, 1.06-1.14), Grade B (RR, 0.46; 95% CI, 0.28-0.75), and Grades C + D + E (RR, 0.21; 95% CI, 0.09-0.45) than the freehand technique, whereas the Renaissance robot-assisted technique showed the same accuracy as the freehand technique in screw positions Grade A, Grade B, and Grades C + D + E. Furthermore, the robot-assisted techniques showed equivalent postoperative stay, visual analogue scale scores, and Oswestry disability index scores to those of the freehand technique and shorter intraoperative radiation exposure time, fewer radiation dose and proximal facet violations but longer surgical time than the freehand technique.

CONCLUSION

The robot-assisted technique is more accurate in pedicle screw placement than the freehand technique. And TINAVI robot-assisted pedicle screw placement is a more accurate alternative to conventional techniques and the Renaissance robot-assisted procedure.

LEVEL OF EVIDENCE

1.

Robotics in spinal surgery

Although the da Vinci robot system has garnered much attention in the realm of surgery over the past few decades, several new surgical robotic systems have been developed for spinal surgery with varying levels of robot autonomy and surgeon-specified input. These devices are currently being considered as potential avenues for increasing the precision of any surgical intervention. The following review will attempt to provide an overview of robotics in modern spine surgery and how these devices will continue to be employed in various sectors across the field.

Robot-assisted percutaneous scaphoid fracture fixation: a report of ten patients

This study reports the technique, efficacy and safety of robotic-assisted, computer-navigated, percutaneous fixation of scaphoid fractures. Ten males with acute undisplaced waist fractures underwent fixation with this method using a commercially available three-dimensional fluoroscopy unit and robotic navigation system. The mean total operative duration was 40 minutes, which comprised of a set-up time of 18 minutes and planning and surgical time of 22 minutes. All patients required only a single guidewire insertion attempt, and there were no screw protuberances or other complications. All fractures united at a mean of 8 weeks. At a mean follow-up of 6.5 months (range 6-8), the mean Mayo wrist score was 96, patient-rated wrist evaluation was 2, flexion-extension arc was 96% and grip strength was 91% of the contralateral side. We conclude from our patients that robotic-assisted percutaneous scaphoid fixation is feasible, safe and accurate, and is a satisfactory method for treating these injuries. Level of evidence: IV.

A "eye-in-body" integrated surgery robot system for stereotactic surgery

PURPOSE

Current stereotactic surgical robots system relies on cumbersome operations such as calibration, tracking and registration to establish the accurate intraoperative coordinate transformation chain, which makes the system not easy to use. To overcome this problem, a novel stereotactic surgical robot system has been proposed and validated.

METHODS

First, a hand-eye integrated scheme is proposed to avoid the intraoperative calibration between robot arm and motion tracking system. Second, a special reference-tool-based patient registration and tracking method is developed to avoid intraoperative registration. Third, a model-free visual servo method is used to reduce the accuracy requirement of hand-eye relationship and robot kinematic model. Finally, a prototype of the system is constructed and performance tests and a pedicle screw drilling experiment are performed.

RESULTS

The results show that the proposed system has acceptable accuracy. The target positioning error in the plane was - 0.68 ± 0.52 mm and 0.06 ± 0.41 mm. The orientation error was 0.43 ± 0.25°. The pedicle screw drilling experiment shows that the system can complete accurate stereotactic surgery.

CONCLUSIONS

The stereotactic surgical robot system described in this paper can perform stereotactic surgery without the intraoperative hand-eye calibration and nor manual registration and can achieve an acceptable position and orientation accuracy while tolerating the errors in the hand-eye coordinate transformation error and the robot kinematics model error.

Image guidance in spine tumor surgery

Beginning with basic stereotactic operative methods in neurosurgery, intraoperative navigation and image guidance systems have since become the norm in that field. Following the introduction of image guidance into spinal surgery, there has been a dramatic increase in its utilization across disciplines and pathologies. Spine tumor surgery encompasses a wide range of complex surgical techniques and treatment strategies. Similarly to deformity correction and trauma surgery, spine navigation holds potential to improve outcomes and optimize surgical technique for spinal tumors. Recent data demonstrate the applicability of neuro-navigation in the field of spinal oncology, particularly for spinal stabilization, maximizing extent of resection and integration of minimally invasive therapies. The rapid introduction of new, less invasive, and ablative surgical techniques in spine oncology coupled with the rising incidence of spinal metastatic disease make it imperative for spine surgeons to be familiar with the indications for and limitations of imaging guidance. Herein, we provide a practical, current concepts narrative review on the use of spinal navigation in three areas of spinal oncology: (a) extent of tumor resection, (b) spinal column stabilization, and (c) focal ablation techniques.

Risk factors for robot-assisted spinal pedicle screw malposition

The accuracy of robot-assisted pedicle screw placement is unstable and remains controversial. The purpose of this study was to determine the risk factors for unsatisfactory Renaissance robot-assisted pedicle screw placement. This was a retrospective study of prospective data. From January 2017 to March 2018, 136 robot-assisted pedicle screw placements were performed in our department for spinal diseases, and a total of 874 screws were evaluated. All screws were assessed by the Gertzbein and Robbins classification. A and B were defined as satisfactory. C, D, and E were defined as unsatisfactory. Intraoperative registration failures due to nontechnical reasons or intraoperative adjustment were also defined as unsatisfactory. According to the evaluated results, the screws were divided into the satisfactory group (Group A) and the unsatisfactory group (Group B). The satisfactory rate was defined as satisfactory screws (the screws in Group A)/total screws, and the accurate rate was defined as accuracy screws (the screws in Group A)/the screws implanted by the robot (total screws - failed registration screws - screws adjusted during the operation). The age, sex, BMI, and BMD as well as the type of disease, the degree of vertebral rotation and the type of screw placement (percutaneous implantation or open implantation) were compared between the two groups, with the assessment of potential risk factors for unsatisfactory robot-assisted screw placement using logistic regression. A total of 874 screws were evaluated; there were 759 screws in Group A and 115 screws in Group B. The satisfactory rate was 86.8% (759/874), and the accuracy rate of the robot-placed screws was 94.4% (759/804). After logistic regression analysis, the independent risk factors were identified as obesity (OR 5.357 [95% CI 2.897–9.906], p < 0.01), osteoporosis, vertebral rotation and the presence of congenital scoliosis (OR 9.835 [95% CI 4.279–22.604], p < 0.01), particularly for severe osteoporosis (T < −3.5) and severe vertebral rotation (III-IV). According to the results of this study, obesity, osteoporosis and congenital scoliosis are risk factors for unsatisfactory robot-assisted screw placement. Furthermore, for surgeons in the initial stage of using a robot, we suggest avoiding cases in which a single risk factor or multiple risk factors exist to ensure the safety of the operation and to help augment the confidence of the surgeons.

[Facet Fixation Combined with Lumbar Interbody Fusion: Comparative Analysis of Clinical Experience and A New Method of Surgical Treatment of Patients with Lumbar Degenerative Diseases]

Background

For the treatment of patients with degenerative diseases of the lumbar spine the technique of pedicle fixation is widespread, when after open decompression channel structure locking screws are introduced into the vertebral body through the back vertebra legs. We first used a fundamentally new way of fixing the rear using the facet-boards Cage «Facet Wedge», when posterior fixation is done by closing the facet joints with minimally invasive, percutaneous method. We have not found data on the clinical efficacy of facet fixation in scientific literature.

Aims

To compare the clinical efficacy of facet fixation combined with interbody fusion in the treatment of patients with degenerative lumbar spine disease.

Materials and Methods

The study included 145 patients who were divided into 2 groups. The study group with long-term observation included patients (n=100) who underwent a new method for lumbar fixation; the method comprises unilateral or bilateral implantation of titanium Cage «facet Wedge» in the joint space facet joint in combination with the anterior, lateral, and transforaminal interbody fusion. Clinical comparison group (n=45) included retrospectively recruited patients who were performed titanium pedicle screw installation after open decompression and interbody fusion posterior lumbar fixation. Dynamic observation and comprehensive evaluation of the treatment clinical results was carried out for 18 months after surgery.

Results

Cage facet installation technology is quite simple, universal for the stabilization of the rear of the complex after interbody fusion from the front, side, and rear access; and does not require the intraoperative application of expensive high-tech equipment. Comparative analysis of the main group showed significantly better results in terms of the duration of the operation [CG 125 (90; 140) min, the CCG 205 (160; 220) min; p=0.01], the volume of blood loss [CG 80 (70; 120) ml, CCG 350 (300; 550) ml; p=0.008], activation time [CG 2 (1; 2) days, 4 CCG (3; 5) days; p=0.02], length of hospitalization [CG 9 (10; 11) days, the CCG 13 (12; 15) days; p=0.03], the level of pain on a visual analog scale [CG 3 (2; 4) mm, CCG 15 (12; 18) mm; p=0.001], quality of life (by index Oswestry) [CG 8 (6; 8) points, the CCG 23 (20; 28) points, p=0.003], and labor rehabilitation [CG 3 (2; 6) months, CCG 9 (6; 12) months; p=0.0001]. The number of postoperative complications in group 1 was 13%, in the 2nd ― 31,1% (p=0,0012). The new method involves fixing the back with considerably less surgical trauma of paravertebral soft tissue that results in early activation of patients, reduction of stay in hospital period, and better functional recovery of patients.

Conclusions

The application of facet fixation combined with interbody fusion in the treatment of patients with degenerative diseases of the lumbar spine allows achieving the best clinical outcomes and fewer postoperative complications during the short and long-term follow-up if compared with the traditional method of transpedicular stabilization. The combination of low-impact and reliability facet fixation techniques for posterior stabilization of the operated segment creates favorable conditions for the restoration of a functional condition of patients, full social and physical rehabilitation.

Navigation of pedicle screws in the thoracic spine with a new electromagnetic navigation system: a human cadaver study

INTRODUCTION

Posterior stabilization of the spine is a standard procedure in spinal surgery. In addition to the standard techniques, several new techniques have been developed. The objective of this cadaveric study was to examine the accuracy of a new electromagnetic navigation system for instrumentation of pedicle screws in the spine.

MATERIAL AND METHOD

Forty-eight pedicle screws were inserted in the thoracic spine of human cadavers using EMF navigation and instruments developed especially for electromagnetic navigation. The screw position was assessed postoperatively by a CT scan.

RESULTS

The screws were classified into 3 groups: grade 1 = ideal position; grade 2 = cortical penetration <2 mm; grade 3 = cortical penetration ≥2 mm. The initial evaluation of the system showed satisfied positioning for the thoracic spine; 37 of 48 screws (77.1%, 95% confidence interval [62.7%, 88%]) were classified as group 1 or 2.

DISCUSSION

The screw placement was satisfactory. The initial results show that there is room for improvement with some changes needed. The ease of use and short setup times should be pointed out. Instrumentation is achieved without restricting the operator's mobility during navigation.

CONCLUSION

The results indicate a good placement technique for pedicle screws. Big advantages are the easy handling of the system.