Image-Based Robotic System for Enhanced Minimally Invasive Intra-Articular Fracture Surgeries

Abstract: Robotic assistance can bring significant improvements to orthopedic fracture surgery: facilitate more accurate fracture fragment repositioning without open access and obviate problems related to the current minimally invasive fracture surgery techniques by providing a better clinical outcome, reduced recovery time, and health-related costs. This paper presents a new design of the robot-assisted fracture surgery (RAFS) system developed at Bristol Robotics Laboratory, featuring a new robotic architecture, and real-time 3D imaging of the fractured anatomy. The technology presented in this paper focuses on distal femur fractures, but can be adapted to the larger domain of fracture surgeries, improving the state-of-the-art in robot assistance in orthopedics. To demonstrate the enhanced performance of the RAFS system, 10 reductions of a distal femur fracture are performed using the system on a bone model. The experimental results clearly demonstrate the accuracy, effectiveness, and safety of the new RAFS system. The system allows the surgeon to precisely reduce the fractures with a reduction accuracy of 1.15 mm and 1.3°, meeting the clinical requirements for this procedure

Recent trends, technical concepts and components of computer-assisted orthopedic surgery systems: A comprehensive review

Computer-assisted orthopedic surgery (CAOS) systems have become one of the most important and challenging types of system in clinical orthopedics, as they enable precise treatment of musculoskeletal diseases, employing modern clinical navigation systems and surgical tools. This paper brings a comprehensive review of recent trends and possibilities of CAOS systems. There are three types of the surgical planning systems, including: systems based on the volumetric images (computer tomography (CT), magnetic resonance imaging (MRI) or ultrasound images), further systems utilize either 2D or 3D fluoroscopic images, and the last one utilizes the kinetic information about the joints and morphological information about the target bones. This complex review is focused on three fundamental aspects of CAOS systems: their essential components, types of CAOS systems, and mechanical tools used in CAOS systems. In this review, we also outline the possibilities for using ultrasound computer-assisted orthopedic surgery (UCAOS) systems as an alternative to conventionally used CAOS systems.Web of Science1923art. no. 519

Image-Guided Surgical Robotic System for Percutaneous Reduction of Joint Fractures

Complex joint fractures often require an open surgical procedure, which is associated with extensive soft tissue damages and longer hospitalization and rehabilitation time. Percutaneous techniques can potentially mitigate these risks but their application to joint fractures is limited by the current sub-optimal 2D intra-operative imaging (fluoroscopy) and by the high forces involved in the fragment manipulation (due to the presence of soft tissue, e.g., muscles) which might result in fracture malreduction. Integration of robotic assistance and 3D image guidance can potentially overcome these issues. The authors propose an image-guided surgical robotic system for the percutaneous treatment of knee joint fractures, i.e., the robot-assisted fracture surgery (RAFS) system. It allows simultaneous manipulation of two bone fragments, safer robot-bone fixation system, and a traction performing robotic manipulator. This system has led to a novel clinical workflow and has been tested both in laboratory and in clinically relevant cadaveric trials. The RAFS system was tested on 9 cadaver specimens and was able to reduce 7 out of 9 distal femur fractures (T- and Y-shape 33-C1) with acceptable accuracy (≈1 mm, ≈5°), demonstrating its applicability to fix knee joint fractures. This study paved the way to develop novel technologies for percutaneous treatment of complex fractures including hip, ankle, and shoulder, thus representing a step toward minimally-invasive fracture surgeries

Vision-based real-time position control of a semi-automated system for robot-assisted joint fracture surgery

Purpose: Joint fracture surgery quality can be improved by robotic system with high-accuracy and high-repeatability fracture fragment manipulation. A new real-time vision-based system for fragment manipulation during robot-assisted fracture surgery was developed and tested. Methods: The control strategy was accomplished by merging fast open-loop control with vision-based control. This two-phase process is designed to eliminate the open-loop positioning errors by closing the control loop using visual feedback provided by an optical tracking system. Evaluation of the control system accuracy was performed using robot positioning trials, and fracture reduction accuracy was tested in trials on ex vivo porcine model.Results: The system resulted in high fracture reduction reliability with a reduction accuracy of 0.09mm (translations) and of (Formula presented.) (rotations), maximum observed errors in the order of 0.12mm (translations) and of (Formula presented.) (rotations), and a reduction repeatability of 0.02mm and (Formula presented.). Conclusions: The proposed vision-based system was shown to be effective and suitable for real joint fracture surgical procedures, contributing a potential improvement of their quality

FORCE-TORQUE MEASUREMENT SYSTEM FOR FRACTURE SURGERY

One of the more difficult tasks in surgery is to apply the optimal instrument forces and torques necessary to conduct an operation without damaging the tissue of the patient. This is especially problematic in surgical robotics, where force-feedback is totally eliminated. Thus, force sensing instruments emerge as a critical need for improving safety and surgical outcome. We propose a new measurement system that can be used in real fracture surgeries to generate quantitative knowledge of forces/torques applied by surgeon on tissues.We instrumented a periosteal elevator with a 6-DOF load-cell in order to measure forces/torques applied by the surgeons on live tissues during fracture surgeries. Acquisition software was developed in LabView to acquire force/torque data together with synchronised visual information (USB camera) of the tip interacting with the tissue, and surgeon voice recording (microphone) describing the actual procedure. Measurement system and surgical protocol were designed according to patient safety and sterilisation standards.The developed technology was tested in a pilot study during real orthopaedic surgery (consisting of removing a metal plate from the femur shaft of a patient) resulting reliable and usable. As demonstrated by subsequent data analysis, coupling force/torque data with video and audio information produced quantitative knowledge of forces/torques applied by the surgeon during the surgery. The outlined approach will be used to perform intensive force measurements during orthopaedic surgeries. The generated quantitative knowledge will be used to design a force controller and optimised actuators for a robot-assisted fracture surgery system under development at the Bristol Robotics Laboratory

Bioabsorbable implants in paediatric supracondylar fractures of the elbow

Background. Operative stabilisation of paediatric supracondylar elbow fractures is most commonly achieved through the use of percutaneous Kirschner wires. These implants are inert, cheap and simple to use. However, the requirement for removal and the possibility of pin site infection provides opportunity for the development of new techniques that eliminate these drawbacks. Bioabsorbable pins that remain in situ and allow definitive closure of skin at the time of surgery could provide such advantages. However, their ability to maintain fracture reduction and their effect on the growth plate has not been adequately evaluated. Hypotheses. The Acumed® Biotrak Helical Nail (a bioabsorbable fixation implant) has comparable strength to Kirschner wires and does not result in significant disruption of the growth plate or subsequent growth. Studies. Three complementary studies were performed. (1) A retrospective cohort analysis was performed to establish the prevalence of complications related to Kirschner wire fixation of paediatric supracondylar elbow fractures. (2) A saw-bone model was designed to compare the mechanical performance of the Helical Nail and Kirschner wires. (3) An ovine model was designed to assess the in vivo effects of the Helical Nail on limb growth and physeal morphology. The surgical practicalities of the device and its potential for use in the paediatric setting were evaluated. The primary outcome was femoral length six months after Helical Nail insertion. Micro-CT evaluation of growth plate thickness, percentage disruption and bony infiltration was undertaken – the first time this technique has been used in a large animal study. Traditional histopathological techniques complimented the Micro-CT analysis and offered comment on the microscopic appearance of the growth plate immediately adjacent to the bioabsorbable nails. Results. The infection rate within a large tertiary referral centre was 9.6%, which was marginally higher than previous cohort studies. Mechanical testing demonstrated that the Helical Nail had comparable strength in rotation, but inferior resistance to posterior translation, when compared to Kirschner wires. In the ovine model, the Helical Nail disrupted 3.4% of the physis. The nails had no effect on femoral growth during the six month study period. Micro-CT analysis of both the helical nail and Kirschner wire groups demonstrated multiple bony bridges, with two cases of physeal tethering in the Helical Nail group. There was no difference in physeal thickness or bony infiltration of the physis. Histopathology did not reveal any significant inflammatory or foreign body reaction adjacent to the nails. Conclusion. The Helical Nail demonstrated a number of encouraging attributes which indicate its potential. However, in its current state the device is not suitable for use in the stabilisation of paediatric supracondylar elbow fractures

Clinical and radiological aspects of traumatic pelvic ring injury

Epidemiological data regarding High-Energy Traumatic Pelvic Ring Injury in Sweden was missing. Further, there was no data regarding current knowledge and level of experience of Swedish first line trauma officers about the management of traumatic pelvic ring injury. While conventional X-ray has been widely criticized as an optimal tool in assessment of pelvic ring injuries, a practical substitute has not been proposed. We planned to study epidemiological aspects of High Energy Traumatic Pelvic Ring Injury using data from the Karolinska Trauma Center. To assess first line trauma medical officer’s knowledge and level of experience regarding acute management of pelvic trauma. To investigate alternative practical options instead of conventional X-ray during the treatment of pelvic fractures. We used data from the Swedish National Trauma Registry (SweTrau). We used the Karolinska University Hospital´s Patient Notes and PACS. We used a questionnaire in order to assess Swedish trauma unit’s medical officers about acute management of pelvic trauma. We further used three dimensional models for image fusion and motion analysis in order to investigate symmetry of human pelvis and to investigate a pelvic fracture model. We found that the incidence of High Energy Traumatic Pelvic Ring Injury was about 3.5/100 000 inhabitants per year in Stockholm. The 30-day mortality was 7.8% and the 1 year mortality was 9%. The main cause of mortality was traumatic brain injury. Intentional injuries had a mortality rate of 15%. The reoperation frequency was 22%. Main cause of reoperation was due to metalwork problems, and a majority of them were potentially avoidable. We found that a majority of the Swedish first line trauma officers were aware of presence of a pelvic binder in their department and knew how to apply it, while there was more experience in the university hospitals. There was a general misconception regarding limitation of pelvic binders as 55% believed that a pelvic binder can stop an arterial bleeding. We were further able to show that human hemi pelvises are symmetrical and the 3D images of the contralateral hemi pelvis can be used for pre-operative templating. We were able to show that using fusion of serial 3D images of a pelvic model, translations of ±0.2 mm and rotations of ±0.2° could be detected. We can hereby conclude that monitoring 30-day mortality seems enough while studying high energy pelvic injuries. Intentional injuries need further future studies as per high mortality rate. Reoperation frequency following fixation of disrupted high energy pelvic fractures is high and needs addressing and early detection. Limitations of pelvic binders should be addressed during the trauma courses. Low dose CT-scan together with serial image fusion can be a future substitute for conventional X-ray. Human hemi pelvises are symmetrical and the contralateral side can be used for templating

Augmented Reality and Artificial Intelligence in Image-Guided and Robot-Assisted Interventions

In minimally invasive orthopedic procedures, the surgeon places wires, screws, and surgical implants through the muscles and bony structures under image guidance. These interventions require alignment of the pre- and intra-operative patient data, the intra-operative scanner, surgical instruments, and the patient. Suboptimal interaction with patient data and challenges in mastering 3D anatomy based on ill-posed 2D interventional images are essential concerns in image-guided therapies. State of the art approaches often support the surgeon by using external navigation systems or ill-conditioned image-based registration methods that both have certain drawbacks. Augmented reality (AR) has been introduced in the operating rooms in the last decade; however, in image-guided interventions, it has often only been considered as a visualization device improving traditional workflows. Consequently, the technology is gaining minimum maturity that it requires to redefine new procedures, user interfaces, and interactions. This dissertation investigates the applications of AR, artificial intelligence, and robotics in interventional medicine. Our solutions were applied in a broad spectrum of problems for various tasks, namely improving imaging and acquisition, image computing and analytics for registration and image understanding, and enhancing the interventional visualization. The benefits of these approaches were also discovered in robot-assisted interventions. We revealed how exemplary workflows are redefined via AR by taking full advantage of head-mounted displays when entirely co-registered with the imaging systems and the environment at all times. The proposed AR landscape is enabled by co-localizing the users and the imaging devices via the operating room environment and exploiting all involved frustums to move spatial information between different bodies. The system's awareness of the geometric and physical characteristics of X-ray imaging allows the exploration of different human-machine interfaces. We also leveraged the principles governing image formation and combined it with deep learning and RGBD sensing to fuse images and reconstruct interventional data. We hope that our holistic approaches towards improving the interface of surgery and enhancing the usability of interventional imaging, not only augments the surgeon's capabilities but also augments the surgical team's experience in carrying out an effective intervention with reduced complications