Pedicle Screw Insertion Surgical Simulator

Scoliosis is a sideway spinal deformity. If the curvature is measured to be more than 50 degrees, the patient can feel significant discomfort. In such cases, surgery is required to straighten the spine. Pedicle screw insertion is a common procedure for scoliosis surgery. The technique requires the placement of screws from the pedicle into the spine. A rod is used to connect all the pedicle screws. The spine is straightened during the connection process. One of the most common techniques used for pedicle screw insertion is called the free hand technique. During free hand surgery, the surgeon creates a screw channel by manually probe into the spine. The lack of visual aid requires the surgeon to rely strongly on haptics feedback. Due to the spine sensitivity and the limited operating range, small changes in force or direction can cause the probe to breach out of the spine. If the breach reaches the spine medial, the spinal cord could be damaged. Even experienced surgeons can not prevent breach. Studies have found that surgeons with 5 or more years of surgical experience have a breach rate of 10.8 %. In this thesis, pedicle screw insertion simulator is developed and examined in detail. The simulator combines visual and haptics sensation to recreate the channel creation process of the surgery. A 2DOF mechanical device is used for the haptics sensation. The device includes a linear actuator and a rotary motor. The simulator was tuned to four different surgical scenarios by 2 expert surgeons. The scenarios are soft probing, hard probing, lateral breach, and in-out-in breach. 10 additional surgeons were asked to participant in a clinical study. Measurements were collected for analysis. The focus of the study is to find if the surgeon can recognize the simulated breach scenarios. Four research questions were examined, and they are: 1. Can experience help the surgeon improve correct breach recognition rate? 2. Can experience help the surgeon improve overall correct recognition rate? 3. Is there any performance difference between surgeons with different experience level? 4. Can the simulation trials become a learning tool for the simulation tasks? Each question has its own null hypothesis and statistical analysis is used to determine if the null hypothesis is rejected. The main conclusion is that there is no statistically significant relationship between the wrong breach or total wrong recognition rate and surgical experience. Furthermore, there is statistically significant in hard probing scenario between surgical experience and vertical force variance. Lastly, ANOVA analysis showed that the breach force and velocity in three trials are close to statistically significant, more data may prove that the simulator can be a training tool for the tasks

DESIGN AND DEVELOPMENT OF IN VITRO TOOLS TO ASSESS FIXATION AND MOTION IN THE SPINE

In vitro biomechanical testing of the spine is an important method for evaluating new surgical methods and components, prior to in vivo implementation. This relies upon special laboratory tools and techniques to create spinal motion and loading similar to those experienced in the body. In this thesis, two different studies were performed to evaluate the effects of spinal fixation and motion. The first study compared the fixation of a novel hollow screw and a conventional solid screw in an in vitro sacral model. Screws were tested in seven cadaveric sacra and subjected to stair-cased cyclic flexion- extension loading to simulate the clinical loading scenario. The hollow screw was less resistant to loosening compared to the solid screw in this model. In the second part of this thesis, a spinal loading simulator was developed as a modification to an existing Instron® materials testing machine to produce motion in a multi-segment spine using applied pure bending moments (i.e. flexibility protocol). A custom-designed 2D optical tracking system was used to record the planar motion achieved. An experimental validation study was performed using the developed apparatus, and showed the device was capable of independently producing repeatable and reproducible spine motions (i.e. flexion-extension, lateral bending, and axial rotation) in a single cadaveric specimen. Future work will focus on the continued development of the simulator for use in the assessment of spinal orthopaedic interventions

Augmented Reality: Mapping Methods and Tools for Enhancing the Human Role in Healthcare HMI

Background: Augmented Reality (AR) represents an innovative technology to improve data visualization and strengthen the human perception. Among Human–Machine Interaction (HMI), medicine can benefit most from the adoption of these digital technologies. In this perspective, the literature on orthopedic surgery techniques based on AR was evaluated, focusing on identifying the limitations and challenges of AR-based healthcare applications, to support the research and the development of further studies. Methods: Studies published from January 2018 to December 2021 were analyzed after a comprehensive search on PubMed, Google Scholar, Scopus, IEEE Xplore, Science Direct, and Wiley Online Library databases. In order to improve the review reporting, the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines were used. Results: Authors selected sixty-two articles meeting the inclusion criteria, which were categorized according to the purpose of the study (intraoperative, training, rehabilitation) and according to the surgical procedure used. Conclusions: AR has the potential to improve orthopedic training and practice by providing an increasingly human-centered clinical approach. Further research can be addressed by this review to cover problems related to hardware limitations, lack of accurate registration and tracking systems, and absence of security protocols

Design, development, manufacturing and biomechanical testing of Stand-alone cage for posterior lumbar interbody fusion

Introduction: The most common method of spinal fusion includes pedicle screws instrumentation, either with or without interbody cage fusion. This thesis aimed to develop and test a novel stand-alone intervertebral device that eliminates the need for pedicle screws and rods. Method: The stand-alone cage was designed in collaboration with spinal surgeons and engineers using computer assisting drawings, and manufactured in titanium by 3D printing. Biomechanical testing comparing the stand-alone cage with standard posterior lumbar interbody fusion (PLIF) in sawbones (n=6) and cadavers (n=8). Result: Compared to PLIF, the stand-alone cage demonstrated no significant difference in range of flexion, lateral bend or axial rotation in sawbones; however, significant increase in range of extension was observed. Among cadavers, the stand-alone cage demonstrated a significant increase in range of motion (ROM) for flexion, extension, lateral bending to the right and total lateral bend ROM; but no significant increase to ROM in axial rotation. Conclusion: Due to the increased ROM associated with the stand-alone cage, this devise is not advisable to use as a fusion implant. Keywords Lumbar spine, anatomy, biomechanics, Posterior lumbar fusion, interbody fusion

Power tool use in orthopaedic surgery: iatrogenic injury, its detection and technological advances

Background: Power tools are an integral part to orthopaedic surgery but have the capacity to cause iatrogenic injury. This systematic review aimed to investigate the prevalence of iatrogenic injury due to power tools in orthopaedic surgery and discuss the current methods 9that can be used to reduce this. Methods: A systematic review of all English language articles using a keyword search was undertaken in Medline, Embase, PubMed and Scopus databases. Exclusion criteria included injuries related to cast saw, temperature induced damage and complications not clearly related to power tool use. Results: 3694 abstracts were retrieved, and 88studies were included in the final analysis. Only a few studies and individual case reports directly looked at prevalence of injury due to power tools. This included 2 studies looking at frequency of vascular injury during femoral fracture fixation (0.49% and 0.2%),2 studies investigating frequency of vertebral artery injury during spinal surgery (0.5% and 0.08%)and 3 studies investigating vascular injury during total joint arthroplasty (124 vascular injuries involving 138 blood vessels,0.13% and 0.1% incidence)in addition to 1 questionnaire sent electronically to surgeons. There are multiple methods to prevent damage during the use of power tools. These include robotics, Revised Manuscript (Maximum 3000 Words) simulation, specific drill settings and real-time feedback techniques such as spectroscopy and electromyography. Conclusion: Power tools have the potential to cause iatrogenic injury to surrounding structures during orthopaedic surgery. Fortunately, the published literature suggests the frequency of iatrogenic injury using orthopaedic power tools is low. There are multiple technologies available to reduce damage using power tools. In high-risk operations the use of advanced technologies to reduce the chance of iatrogenic injury should be considered. Clinical Relevance: Power tools used during orthopaedic surgery have the potential to cause iatrogenic injury through mechanisms such as plunging or over-sawing. Understanding the prevalence of these injuries and mechanisms to increase safety would be useful to surgeons in their daily practice and have the potential to reduce iatrogenic injury in future

Augmented and virtual reality in spine surgery, current applications and future potentials

BACKGROUND CONTEXT: The field of artificial intelligence (AI) is rapidly advancing, especially with recent improvements in deep learning (DL) techniques. Augmented (AR) and virtual reality (VR) are finding their place in healthcare, and spine surgery is no exception. The unique capabilities and advantages of AR and VR devices include their low cost, flexible integration with other technologies, user-friendly features and their application in navigation systems, which makes them beneficial across different aspects of spine surgery. Despite the use of AR for pedicle screw placement, targeted cervical foraminotomy, bone biopsy, osteotomy planning, and percutaneous intervention, the current applications of AR and VR in spine surgery remain limited. PURPOSE: The primary goal of this study was to provide the spine surgeons and clinical researchers with the general information about the current applications, future potentials, and accessibility of AR and VR systems in spine surgery. STUDY DESIGN/SETTING: We reviewed titles of more than 250 journal papers from google scholar and PubMed with search words: augmented reality, virtual reality, spine surgery, and orthopaedic, out of which 89 related papers were selected for abstract review. Finally, full text of 67 papers were analyzed and reviewed. METHODS: The papers were divided into four groups: technological papers, applications in surgery, applications in spine education and training, and general application in orthopaedic. A team of two reviewers performed paper reviews and a thorough web search to ensure the most updated state of the art in each of four group is captured in the review. RESULTS: In this review we discuss the current state of the art in AR and VR hardware, their preoperative applications and surgical applications in spine surgery. Finally, we discuss the future potentials of AR and VR and their integration with AI, robotic surgery, gaming, and wearables. CONCLUSIONS: AR and VR are promising technologies that will soon become part of standard of care in spine surgery. (C) 2021 Published by Elsevier Inc

Haptic Training Simulator for Pedicle Screw Insertion in Scoliosis Surgery

This thesis develops a haptic training simulator that imitates the sensations experienced by a surgeon in pedicle screw insertions in a scoliosis surgery. Pedicle screw insertion is a common treatment for fixing spinal deformities in idiopathic scoliosis. Surgeons using the free hand technique are guided primarily by haptic feedback. A vital step in this free hand technique is the use of a probe to make a channel through the vertebrae pedicle. This is a sensitive process which carries risk of serious mechanical, neurological and vascular complications. Surgeons are currently trained using cadavers or live patients. Cadavers often have vertebrae that are softer than the real surgeons would typically encounter, while training on live patients carries the obvious issue of increased risk of complications to the patient. In this thesis, a haptic virtual reality simulator is designed and studied as a training tool for surgeons in this procedure. Creating a pathway through the pedicle by the free-hand technique is composed of two main degrees of freedom: rotation and linear progression. The rotary stage of the device which was developed by a previous student, is enhanced in this research by adding hardware, improving the haptic model and proposing techniques to couple the rotary and linear degree of freedom. Haptic model parameters for a spine surgery with normal bone density are then clinically tuned within a user study. Over ten surgeons of varying experience levels used the simulator and were able to change various parameters in order to tune the simulator to what felt most realistic. The surgeons also evaluated the simulator for its feasibility and usefulness. Four research questions were investigated. First, can a reference set of values be found that replicate the surgeon's interpretation of the surgical scenario? Second, how are the rotary stage parameters influenced in the presence of linear effects? Third, do the results differ across different expertise levels? Finally, can the simulator serve as a useful tool in the education of surgical trainees for teaching channel creation in pedicle screw insertion? Statistical analysis are carried out to examine the research questions. The results indicates the feasibility of the simulator for surgical education

Assessment of Surgical Procedural Time, Pedicle Screw Accuracy, and Clinician Radiation Exposure of a Novel Robotic Navigation System Compared With Conventional Open and Percutaneous Freehand Techniques: A Cadaveric Investigation

STUDY DESIGN: Cadaveric study. OBJECTIVE: To evaluate accuracy, radiation exposure, and surgical time of a new robotic-assisted navigation (RAN) platform compared with freehand techniques in conventional open and percutaneous procedures. METHODS: Ten board-certified surgeons inserted 16 pedicle screws at T10-L5 (n = 40 per technique) in 10 human cadaveric torsos. Pedicle screws were inserted with (1) conventional MIS technique (L2-L5, patient left pedicles), (2) MIS RAN (L2-L5, patient right pedicles), (3) conventional open technique (T10-L1, patient left pedicles), and (4) open RAN (T10-L1, patient right pedicles). Output included (1) operative time, (2) number of fluoroscopic images, and (3) screw accuracy. RESULTS: In the MIS group, compared with the freehand technique, RAN allowed for use of larger screws (diameter: 6.6 ± 0.6 mm vs 6.3 ± 0.5 mm; length: 50.3 ± 4.1 mm vs 46.9 ± 3.5 mm), decreased the number of breaches \u3e2 mm (0 vs 7), fewer fluoroscopic images (0 ± 0 vs 108.3 ± 30.9), and surgical procedure time per screw (3.6 ± 0.4 minutes vs 7.6 ± 2.0 minutes) (all CONCLUSION: RAN significantly improved accuracy and decreased radiation exposure in comparison to freehand techniques in both conventional open and percutaneous surgical procedures in cadavers. RAN significantly increased setup time compared with both conventional procedures

Desktop-based computer-assisted orthopedic training system for spinal surgery

Background Simulation and surgical training has moved on since its inception during the end of the last century. The trainees are getting more exposed to computers and laboratory training in different subspecialties. More needs to be done in orthopedic simulation in spinal surgery.Aims To develop a training system for pedicle screw fixation and validate its effectiveness in a cohort of junior orthopedic trainees.Training System Fully simulated computer-navigated training system is used to train junior orthopedic trainees perform pedicle screw insertion in the lumbar spine. Real patient computed tomography scans are used to produce the real-time fluoroscopic images of the lumbar spine.Material and Methods The training system was developed to simulate pedicle screw insertion in the lumbar spine. A total of 12 orthopedic senior house officers performed pedicle screw insertion in the lumbar spine before and after the training on training system. The results were assessed based on the scoring system, which included the amount of time taken, accuracy of pedicle screw insertion, and the number of exposures requested to complete the procedure.Results The result shows a significant improvement in amount of time taken, accuracy of fixation, and the number of exposures after the training on simulator system. This was statistically significant using paired Student t test (p < 0.05).Conclusion Fully simulated computer-navigated training system is an efficient training tool for young orthopedic trainees. This system can be used to augment training in the operating room, and trainees acquire their skills in the comfort of their study room or in the training room in the hospital. The system has the potential to be used in various other orthopedic procedures for learning of technical skills in a manner aimed at ensuring a smooth escalation in task complexity leading to the better performance of procedures in the operating theater