Significance of preoperative planning simulator for junior surgeons' training of pedicle screw insertion

Robotic-Assisted Spine Surgery: Role in Training the Next Generation of Spine Surgeons

OBJECTIVE

This study aimed to assess the degree of interest in robot-assisted spine surgery (RASS) among residents and to investigate the learning curve for beginners performing robotic surgery.

METHODS

We conducted a survey to assess awareness and interest in RASS among young neurosurgery residents. Subsequently, we offered a hands-on training program using a dummy to educate one resident. After completing the program, the trained resident performed spinal fusion surgery with robotic assistance under the supervision of a mentor. The clinical outcomes and learning curve associated with robotic surgery were then analyzed.

RESULTS

Neurosurgical residents had limited opportunities to participate in spinal surgery during their training. Despite this, there was a significant interest in the emerging field of robotic surgery. A trained resident performed RASS under the supervision of a senior surgeon. A total of 166 screw insertions were attempted in 28 patients, with 2 screws failing due to skiving. According to the Gertzbein-Robbins classification, 85.54% of the screws were rated as grade A, 11.58% as grade B, 0.6% as grade C, and 1.2% as grade D. The clinical acceptance rate was approximately 96.99%, which is comparable to the results reported by senior experts and time per screw statistically significantly decreased as experience was gained.

CONCLUSION

RASS can be performed with high accuracy within a relatively short timeframe, if residents receive adequate training.

Man versus machine: Automatic pedicle screw planning using registration-based techniques compared with manual screw planning for thoracolumbar fusion surgeries

OBJECTIVE

This study evaluates the precision of a commercially available spine planning software in automatic spine labelling and screw-trajectory proposal.

METHODS

The software uses automatic segmentation and registration of the vertebra to generate screw proposals. 877 trajectories were compared. Four neurosurgeons assessed suggested trajectories, performed corrections, and manually planned pedicle screws. Additionally, automatic identification/labelling was evaluated.

RESULTS

Automatic labelling was correct in 89% of the cases. 92.9% of automatically planned trajectories were in accordance with G&R grade A + B. Automatic mode reduced the time spent planning screw trajectories by 7 s per screw to 20 s per vertebra. Manual mode yielded differences in screw-length between surgeons (largest distribution peak: 5 mm), automatic in contrast at 0 mm. The size of suggested pedicle screws was significantly smaller (largest peaks in difference between 0.5 and 3 mm) than the surgeon's choice.

CONCLUSION

Automatic identification of vertebrae works in most cases and suggested pedicle screw trajectories are acceptable. So far, it does not substitute for an experienced surgeon's assessment.

Simulation training to retool practicing orthopedic surgeons is rare

Purpose

Modern surgical practice is continuously changing as technology develops. New techniques are often implemented after a surgeon has made the transition to independent clinical practice. There is therefore a need to 'retool' technical skills. Additionally, practicing surgeons must maintain and develop skills such as leadership, communication, critical thinking, teaching, and mentoring. Our aim was to perform a scoping review to assess the current status of simulation education for practicing Orthopedic Surgeons (OS).

Methods

A 10 year search of PubMed, ERIC, and Web of Science was performed with a medical librarian. Controlled vocabulary Medical Subject Headings terms and natural language were developed with subject matter experts describing simulation, training and OS. Two trained reviewers evaluated all abstracts for inclusion. Exclusion criteria were articles that did not assess simulation education involving practicing OS. Data were extracted from the included full text articles by two reviewers: details of study design, type of participants, type of simulation and role of OS in the educational event.

Results

Initial search identified 1824 articles of which 443 were duplicates, and 1381 articles were further screened. Of these, 1155 were excluded, 226 full text articles were assessed for eligibility and 80 included in analysis. Most were published in the last 6 years and from the United States. The majority (99%) described technical skill simulations (arthroscopy 56%, screw placement 23%, ligament reconstruction 19%). OS were rarely the only learners with 91% studies also having residents participate. OS were the targeted learner in 6% studies. OS provided content validity for 15 (19%) and construct validity in 59 (74%) studies.

Conclusions

Simulation training to educate practicing OS is rare. OS are often used to validate work rather than being the center of an educational endeavor. A refocusing is needed to provide adequate training for practicing surgeons to retool skills as new techniques become available.

Pedagogy in spine surgery: developing a free and open-access virtual simulator for lumbar pedicle screws placement

PURPOSE

Simulators for pedicle screws placement range from basic sawbones to virtual reality. Yet, they remain expensive and often require specific devices. No free online virtual simulator has yet been developed. The goal was to design a freely accessible Web-based simulator.

METHODS

The computer simulator consisted of a lumbar spine, a red box hiding the pedicles and five pairs of screws. After inserting the screws, the red box was removed to assess their position. A validation study was conducted with 24 medical students randomized into a simulation and a control group. All had a basic course on pedicle screws. The 12 simulation group students performed two sessions on computer. All 24 students then conducted a final common step on sawbones. The number of misplaced screws, types of breaches, and simulation times were analyzed.

RESULTS

In the final sawbones simulation, 96 real screws were studied. Control group misplaced 50% of their screws compared with only 20.8% in the simulation group (p < 0.05). More careful, simulation group students were slower to insert their real screws. Over the two computer simulations, the rate of misplaced screws decreased (12.5% vs. 38.3%), showing a good handling of the simulator. Students were able to analyze and correct their pedicle breaches.

CONCLUSION

This tool is the first free online lumbar pedicle screws simulator. Simulation helped students to better position the final real screws on sawbones. This project showed it was possible to create a free educational tool with no special equipment.

LEVEL OF EVIDENCE

Level 3.

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

BACKGROUND AND OBJECTIVE

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

METHODS

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

KEY CONTENT AND FINDINGS

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

CONCLUSIONS

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

XR (Extended Reality: Virtual Reality, Augmented Reality, Mixed Reality) Technology in Spine Medicine: Status Quo and Quo Vadis

In recent years, with the rapid advancement and consumerization of virtual reality, augmented reality, mixed reality, and extended reality (XR) technology, the use of XR technology in spine medicine has also become increasingly popular. The rising use of XR technology in spine medicine has also been accelerated by the recent wave of digital transformation (i.e., case-specific three-dimensional medical images and holograms, wearable sensors, video cameras, fifth generation, artificial intelligence, and head-mounted displays), and further accelerated by the COVID-19 pandemic and the increase in minimally invasive spine surgery. The COVID-19 pandemic has a negative impact on society, but positive impacts can also be expected, including the continued spread and adoption of telemedicine services (i.e., tele-education, tele-surgery, tele-rehabilitation) that promote digital transformation. The purpose of this narrative review is to describe the accelerators of XR (VR, AR, MR) technology in spine medicine and then to provide a comprehensive review of the use of XR technology in spine medicine, including surgery, consultation, education, and rehabilitation, as well as to identify its limitations and future perspectives (status quo and quo vadis).

Robotics in Spine Surgery and Spine Surgery Training

The increasing interest and advancements in robotic spine surgery parallels a growing emphasis on maximizing patient safety and outcomes. In addition, an increasing interest in minimally invasive spine surgery has further fueled robotic development, as robotic guidance systems are aptly suited for these procedures. This review aims to address 3 of the most critical aspects of robotics in spine surgery today: salient details regarding the current and future development of robotic systems and functionalities, the reported accuracy of implant placement over the years, and how the implementation of robotic systems will impact the training of future generations of spine surgeons. As current systems establish themselves as highly accurate tools for implant placement, the development of novel features, including even robotic-assisted decompression, will likely occur. As spine surgery robots evolve and become increasingly adopted, it is likely that resident and fellow education will follow suit, leading to unique opportunities for both established surgeons and trainees.

Analysis of Tools Used in Assessing Technical Skills and Operative Competence in Trauma and Orthopaedic Surgical Training: A Systematic Review

BACKGROUND

Robust assessment of skills acquisition and surgical performance during training is vital to ensuring operative competence among orthopaedic surgeons. A move to competency-based surgical training requires the use of tools that can assess surgical skills objectively and systematically. The aim of this systematic review was to describe the evidence for the utility of assessment tools used in evaluating operative performance in trauma and orthopaedic surgical training.

METHODS

We performed a comprehensive literature search of MEDLINE, Embase, and Google Scholar databases to June 2019. From eligible studies we abstracted data on study aim, assessment format (live theater or simulated setting), skills assessed, and tools or metrics used to assess surgical performance. The strengths, limitations, and psychometric properties of the assessment tools are reported on the basis of previously defined utility criteria.

RESULTS

One hundred and five studies published between 1990 and 2019 were included. Forty-two studies involved open orthopaedic surgical procedures, and 63 involved arthroscopy. The majority (85%) were used in the simulated environment. There was wide variation in the type of assessment tools in used, the strengths and weaknesses of which are assessor and setting-dependent.

CONCLUSIONS

Current technical skills-assessment tools in trauma and orthopaedic surgery are largely procedure-specific and limited to research use in the simulated environment. An objective technical skills-assessment tool that is suitable for use in the live operative theater requires development and validation, to ensure proper competency-based assessment of surgical performance and readiness for unsupervised clinical practice.

CLINICAL RELEVANCE

Trainers and trainees can gain further insight into the technical skills assessment tools that they use in practice through the utility evidence provided.

Virtual reality as a learning tool in spinal anatomy and surgical techniques

Background

Surgical simulation is a valuable educational tool for trainees to practice in a safe, standardized, and controlled environment. Interactive feedback-based virtual reality (VR) has recently moved to the forefront of spine surgery training, with most commercial products focusing on instrumentation. There is a paucity of learning tools directed at decompression principles. The purpose of this study was to evaluate the efficacy of VR simulation and its educational role in learning spinal anatomy and decompressive techniques.

Methods

A VR simulation module was created with custom-developed software. Orthopaedic and neurosurgical trainees were prospectively enrolled and interacted with patient-specific 3D models of lumbar spinal stenosis while wearing a headset. A surgical toolkit allowed users to perform surgical decompression, specifically removing soft tissues and bone. The module allowed users to perform various techniques in posterior decompressions and comprehend anatomic areas of stenosis. Pre- and post-module testing, and utility questionnaires were administered to provide both quantitative and qualitative evaluation of the module as a learning device.

Results

28 trainees were enrolled (20-orthopaedic, 8-neurosurgery) in the study. Pre-test scores on anatomic knowledge progressively improved and showed strong positive correlation with year-in-training (Pearson's r = 0.79). Following simulation, the average improvement in post-test scores was 11.4% in junior trainees (PGYI-III), and 1.0% in senior trainees (PGYIII-Fellows). Knowledge improvement approached statistical significance amongst junior trainees (p = 0.0542). 89% of participants found the VR module useful in understanding and learning the pathology of spinal stenosis. 71% found it useful in comprehending decompressive techniques. 96% believed it had utility in preoperative planning with patient-specific models.

Conclusions

Our original VR spinal decompression simulation has shown to be overwhelmingly positively received amongst trainees as both a learning module of patho-anatomy and patient-specific preoperative planning, with particular benefit for junior trainees.

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

Background

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

Methods

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

Results

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

Conclusions

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

Assessment of technical skill in hip fracture surgery using the postoperative radiograph: pilot development and validation of a final product analysis core outcome set

Aims

To develop a core outcome set of measurements from postoperative radiographs that can be used to assess technical skill in performing dynamic hip screw (DHS) and hemiarthroplasty, and to validate these against Van der Vleuten’s criteria for effective assessment.

Methods

A Delphi exercise was undertaken at a regional major trauma centre to identify candidate measurement items. The feasibility of taking these measurements was tested by two of the authors (HKJ, GTRP). Validity and reliability were examined using the radiographs of operations performed by orthopaedic resident participants (n = 28) of a multicentre randomized controlled educational trial (ISRCTN20431944). Trainees were divided into novice and intermediate groups, defined as having performed < ten or ≥ ten cases each for DHS and hemiarthroplasty at baseline. The procedure-based assessment (PBA) global rating score was assumed as the gold standard assessment for the purposes of concurrent validity. Intra- and inter-rater reliability testing were performed on a random subset of 25 cases.

Results

In total, 327 DHS and 248 hemiarthroplasty procedures were performed by 28 postgraduate year (PGY) 3 to 5 orthopaedic trainees during the 2014 to 2015 surgical training year at nine NHS hospitals in the West Midlands, UK. Overall, 109 PBAs were completed for DHS and 80 for hemiarthroplasty. Expert consensus identified four ‘final product analysis’ (FPA) radiological parameters of technical success for DHS: tip-apex distance (TAD); lag screw position in the femoral head; flushness of the plate against the lateral femoral cortex; and eight-cortex hold of the plate screws. Three parameters were identified for hemiarthroplasty: leg length discrepancy; femoral stem alignment; and femoral offset. Face validity, content validity, and feasibility were excellent. For all measurements, performance was better in the intermediate compared with the novice group, and this was statistically significant for TAD (p < 0.001) and femoral stem alignment (p = 0.023). Concurrent validity was poor when measured against global PBA score. This may be explained by the fact that they are measuring difference facets of competence. Intra-and inter-rater reliability were excellent for TAD, moderate for lag screw position (DHS), and moderate for leg length discrepancy (hemiarthroplasty). Use of a large multicentre dataset suggests good generalizability of the results to other settings. Assessment using FPA was time- and cost-effective compared with PBA.

Conclusion

Final product analysis using post-implantation radiographs to measure technical skill in hip fracture surgery is feasible, valid, reliable, and cost-effective. It can complement traditional workplace-based assessment for measuring performance in the real-world operating room . It may have particular utility in competency-based training frameworks and for assessing skill transfer from the simulated to live operating theatre.

Cite this article: Bone Joint Open 2020;1-9:594–604.

Innovation in Orthopaedic Surgery Education: Novel Tools for Modern Times

Orthopaedic residency training has and will continue to evolve with a wide variety of changes. Hands-on surgical simulation "boot camps," computerized simulation of surgical process, and even virtual reality simulators, all can help trainees acquire surgical experience without compromising patient care. Low-cost training modules help remedy the rising costs associated with teaching complex orthopaedic surgery skills. Motion tracking and checklists help refine standardization of assessment. As technology and healthcare systems continue to grow, we encourage training programs to keep pace by considering engagement of these tools.

A review of computer-assisted orthopaedic surgery systems

BACKGROUND

Computer-assisted orthopaedic surgery systems have great potential, but no review has focused on computer-assisted surgery systems for the spine, hip, and knee.

METHODS

A systematic search was performed in Web of Science and PubMed. We searched the literature on computer-assisted orthopaedic surgery systems from 2008 to the present and focused on three aspects of systems: training, planning, and intraoperative navigation.

RESULTS AND DISCUSSION

In this review study, we reviewed 34 surgical training systems, 31 surgical planning systems, and 41 surgical navigation systems. The functions and characteristics of the surgical systems were compared and analysed, and the current concerns about and the impact of the surgical systems on doctors and surgery were clarified.

CONCLUSION

Computer-assisted orthopaedic surgery systems are still in the development stage. Future surgical training systems should include synthetic models with patient anatomy. Surgical planning systems with automatic planning should be developed, and surgical navigation systems with multimodal fusion, robotic assistance and imaging should be developed.

Computed Tomography-Based Preoperative Simulation System for Pedicle Screw Fixation in Spinal Surgery

BACKGROUND

A preoperative planning system facilitates improving surgical outcomes that depend on the experience of the surgeons, thanks to real-time interaction between the system and surgeons. It visualizes intermediate surgical planning results to help surgeons discuss the planning. The purpose of this study was to demonstrate the use of a newly-developed preoperative planning system for surgeons less experienced in pedicle-screw fixation in spinal surgery, especially on patients with anatomical variations.

METHODS

The marching cubes algorithm, a typical surface extraction technique, was applied to computed tomography (CT) images of vertebrae to enable three-dimensional (3D) reconstruction of a spinal mesh. Real-time processing of such data is difficult, as the surface mesh extracted from high-resolution CT data is rough, and the size of the mesh is large. To mitigate these factors, Laplacian smoothing was applied, followed by application of a quadric error metric-based mesh simplification to reduce the mesh size for the level-of-detail (LOD) image. Taubin smoothing was applied to smooth out the rough surface. On a multiplanar reconstruction (MPR) cross-sectional image or a 3D model view, the insertion position and orientation of the pedicle screw were manipulated using a mouse. The results after insertion were then visualized in each image.

RESULTS

The system was used for pre-planning pedicle-screw fixation in spinal surgery. Using any pointing device such as a mouse, surgeons can manipulate the position and angle of the screws. The pedicle screws were easy to manipulate intuitively on the MPR images, and the accuracy of screw fixation was confirmed on a trajectory view and 3D images. After surgery, CT scans were performed again, and the CT images were checked to ensure that the screws were inserted properly.

CONCLUSION

The preoperative planning system allows surgeons and students who are not familiar with pedicle-screw fixation to safely undertake surgery following preoperative planning. It also provides opportunities for screw-fixation training and simulation.

Virtual reality in spinal endoscopy: a paradigm shift in education to support spine surgeons

Background

Minimally invasive spine surgery (MISS) and endoscopic spine surgery have continually evolving indications in the cervical, thoracic, and lumbar spine. Endoscopic spine surgery entails treatment of disc disease, stenosis, spondylolisthesis, radiculopathy, and deformity. MISS involves complex motor skills in regions of variable anatomy. Simulator use has been proposed to aid in training and skill retention, preoperative planning, and intraoperative use.

Methods

A systematic review of five databases was performed for publications pertaining to the use of virtual (VR), augmented (AR), and mixed (MR) reality in MISS and spinal endoscopic surgery. Qualitative data analysis was undertaken with focus of study design, quality, and reported outcomes. Study quality was assessed using the Medical Education Research Quality Instrument (MERSQI) score and level of evidence (LoE) by a modified Oxford Centre for Evidence-Based Medicine (OCEBM) level for simulation in medicine.

Results

Thirty-eight studies were retained for data collection. Studies were of intervention-control, clinical application, and pilot or cross-sectional design. Identified articles illustrated use of VR, AR, and MR in all study designs. Procedures included pedicle cannulation and screw insertion, vertebroplasty, kyphoplasty, percutaneous transforaminal endoscopic discectomy (PTED), lumbar puncture and facet injection, transvertebral anterior cervical foraminotomy (TVACF) and posterior cervical laminoforaminotomy. Overall MERSQI score was low-to-medium [M =9.71 (SD =2.60); range, 4.5-13.5], and LoE was predominantly low given the number of purely descriptive articles, or low-quality randomized studies.

Conclusions

The current scope of VR, AR, and MR surgical simulators in MISS and spinal endoscopic surgery was described. Studies demonstrate improvement in technical skill and patient outcomes in short term follow-up. Despite this, overall study quality and levels of evidence remain low. Cohesive study design and reporting with focus on transfer validity in training scenarios, and patient derived outcome measures in clinical studies are required to further advance the field.

Systematic Review of Patient-Specific Surgical Simulation: Toward Advancing Medical Education

OBJECTIVE

Simulation-based education has been shown to be an effective tool to teach foundational technical skills in various surgical specialties. However, most of the current simulations are limited to generic scenarios and do not allow continuation of the learning curve beyond basic technical skills to prepare for more advanced expertise, such as patient-specific surgical planning. The objective of this study was to evaluate the current medical literature with respect to the utilization and educational value of patient-specific simulations for surgical training.

METHODS

We performed a systematic review of the literature using Pubmed, Embase, and Scopus focusing on themes of simulation, patient-specific, surgical procedure, and education. The study included randomized controlled trials, cohort studies, and case-control studies published between 2005 and 2016. Two independent reviewers (W.H.R. and N.D) conducted the study appraisal, data abstraction, and quality assessment of the studies.

RESULTS

The search identified 13 studies that met the inclusion criteria; 7 studies employed computer simulations and 6 studies used 3-dimensional (3D) synthetic models. A number of surgical specialties evaluated patient-specific simulation, including neurosurgery, vascular surgery, orthopedic surgery, and interventional radiology. However, most studies were small in size and primarily aimed at feasibility assessments and early validation.

CONCLUSIONS

Early evidence has shown feasibility and utility of patient-specific simulation for surgical education. With further development of this technology, simulation-based education may be able to support training of higher-level competencies outside the clinical settingto aid learners in their development of surgical skills.

Robot assisted navigated drilling for percutaneous pedicle screw placement: A preliminary animal study

BACKGROUND

There is much more radiation exposure to the surgeons during minimally invasive pedicle screws placement. In order to ease the surgeon's hand-eye coordination and to reduce the iatrogenic radiation injury to the surgeons, a robot assisted percutaneous pedicle screw placement is useful. This study assesses the feasibility and clinical value of robot assisted navigated drilling for pedicle screw placement and the results thus achieved formed the basis for the development of a new robot for pedicle screw fixation surgery.

MATERIALS AND METHODS

Preoperative computed tomography (CT) of eight bovine lumbar spines (L1-L5) in axial plane were captured for each vertebra, the entry points and trajectories of the screws were preoperatively planned. On the basis of preoperative CT scans and intraoperative fluoroscopy, we aligned the robot drill to the desired entry point and trajectory, as dictated by the surgeon's preoperative plan. Eight bovine lumbar spines were inserted 80 K-wires using the spine robot system. The time for system registration and pedicle drilling, fluoroscopy times were measured and recorded. Postoperative CT scans were used to assess the position of the K-wires.

RESULTS

Assisted by spine robot system, the average time for system registration was (343.4 ± 18.4) s, the average time for procedure of drilling one pedicle screw trajectory was (89.5 ± 6.1) s, times of fluoroscopy for drilling one pedicle screw were (2.9 ± 0.8) times. Overall, 12 (15.0%) of the 80 K-wires violated the pedicle wall. Four screws (5.0%) were medial to the pedicle and 8 (10.5%) were lateral. The number of K-wires wholly within the pedicle were 68 (85%).

CONCLUSIONS

The preliminary study supports the view that computer assisted pedicle screw fixation using spinal robot is feasible and the robot can decrease the intraoperative fluoroscopy time during the minimally invasive pedicle screw fixation surgery. As spine robotic surgery is still in its infancy, further research in this field is worthwhile especially the accuracy of spine robot system should be improved.