Assessing the Accuracy Factors in the Determination of Postoperative Acetabular Cup Orientation Using Hybrid 2D-3D Registration

Single standard anteroposterior radiograph-based methods for measuring cup orientation following total hip arthroplasty (THA) are subject to substantial errors if the individual pelvic orientation with respect to X-ray plate is not taken into consideration. Previously, we proposed to use a hybrid 2D-3D registration scheme to determine the postoperative acetabular cup orientation and developed an object-oriented cross-program called "HipMatch.” However, its accuracy and robustness have not been fully investigated. To assess the potential factors that may affect the accuracy and robustness of the hybrid 2D-3D registration scheme in determining the postoperative acetabular cup orientation, a comprehensive validation study using a cadaver pelvis was performed. Nine X-ray radiographs taken from different pelvic positions relative to the X-ray plate and two computed tomography volumes of the pelvis with one acquired before the cup implantation and the other acquired after the cup implantation were used in the validation study. Potential factors that may affect the accuracy and robustness of the hybrid 2D-3D registration scheme were experimentally determined. Our experimental results demonstrate that (1) the plain radiograph-based method is not accurate; (2) the hybrid 2D-3D registration scheme helps to improve the estimation accuracy; (3) the hybrid 2D-3D registration scheme can robustly and accurately estimate the cup orientation even when a big portion of the radiograph is occluded; and (4) image resolution has minor effect on the estimation accuracy. The hybrid 2D-3D registration scheme is an accurate and robust method to measure exact cup orientation in THA. It holds the promise to be a valuable tool for clinical routine usage for providing evidence-based informatio

Computer assisted determination of acetabular cup orientation using 2D-3D image registration

Background: 2D-3D image-based registration methods have been developed to measure acetabular cup orientation after total hip arthroplasty (THA). These methods require registration of both the prosthesis and the CT images to 2D radiographs and compute implant position with respect to a reference. The application of these methods is limited in clinical practice due to two limitations: (1) the requirement of a computer-aided design (CAD) model of the prosthesis, which may be unavailable due to the proprietary concerns of the manufacturer, and (2) the requirement of either multiple radiographs or radiograph-specific calibration, usually unavailable for retrospective studies. In this paper, we propose a new method to address these limitations. Methods: A new formulation for determination of post-operative cup orientation, which couples a radiographic measurement with 2D-3D image matching, was developed. In our formulation, the radiographic measurement can be obtained with known methods so that the challenge lies in the 2D-3D image matching. To solve this problem, a hybrid 2D-3D registration scheme combining a landmark-to-ray 2D-3D alignment with a robust intensity-based 2D-3D registration was used. The hybrid 2D-3D registration scheme allows computing both the post-operative cup orientation with respect to an anatomical reference and the pelvic tilt and rotation with respect to the X-ray imaging table/plate. The method was validated using 2D adult cadaver hips. Results: Using the hybrid 2D-3D registration scheme, our method showed a mean accuracy of 1.0 ± 0.7° (range from 0.1°to2.0°) for inclination and 1.7 ± 1.2° (range from 0.0° to 3.9°) for anteversion, taking the measurements from post-operative CT images as ground truths. Conclusions: Our new solution formulation and the hybrid 2D-3D registration scheme facilitate estimation of post-operative cup orientation and measurement of pelvic tilt and rotatio

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

Patient-Specific Implants in Musculoskeletal (Orthopedic) Surgery

Most of the treatments in medicine are patient specific, aren’t they? So why should we bother with individualizing implants if we adapt our therapy to patients anyway? Looking at the neighboring field of oncologic treatment, you would not question the fact that individualization of tumor therapy with personalized antibodies has led to the thriving of this field in terms of success in patient survival and positive responses to alternatives for conventional treatments. Regarding the latest cutting-edge developments in orthopedic surgery and biotechnology, including new imaging techniques and 3D-printing of bone substitutes as well as implants, we do have an armamentarium available to stimulate the race for innovation in medicine. This Special Issue of Journal of Personalized Medicine will gather all relevant new and developed techniques already in clinical practice. Examples include the developments in revision arthroplasty and tumor (pelvic replacement) surgery to recreate individual defects, individualized implants for primary arthroplasty to establish physiological joint kinematics, and personalized implants in fracture treatment, to name but a few

Personalized Hip and Knee Joint Replacement

This open access book describes and illustrates the surgical techniques, implants, and technologies used for the purpose of personalized implantation of hip and knee components. This new and flourishing treatment philosophy offers important benefits over conventional systematic techniques, including component positioning appropriate to individual anatomy, improved surgical reproducibility and prosthetic performance, and a reduction in complications. The techniques described in the book aim to reproduce patients’ native anatomy and physiological joint laxity, thereby improving the prosthetic hip/knee kinematics and functional outcomes in the quest of the forgotten joint. They include kinematically aligned total knee/total hip arthroplasty, partial knee replacement, and hip resurfacing. The relevance of available and emerging technological tools for these personalized approaches is also explained, with coverage of, for example, robotics, computer-assisted surgery, and augmented reality. Contributions from surgeons who are considered world leaders in diverse fields of this novel surgical philosophy make this open access book will invaluable to a wide readership, from trainees at all levels to consultants practicing lower limb surger

1st EFORT European Consensus: Medical & Scientific Research Requirements for the Clinical Introduction of Artificial Joint Arthroplasty Devices

Innovations in Orthopaedics and Traumatology have contributed to the achievement of a high-quality level of care in musculoskeletal disorders and injuries over the past decades. The applications of new implants as well as diagnostic and therapeutic techniques in addition to implementation of clinical research, have significantly improved patient outcomes, reduced complication rates and length of hospital stay in many areas. However, the regulatory framework is extensive, and there is a lack of understanding and clarity in daily practice what the meaning of clinical & pre‐clinical evidence as required by the MDR is. Thus, understanding and clarity are of utmost importance for introduction of new implants and implant-related instrumentation in combination with surgical technique to ensure a safe use of implants and treatment of patients. Therefore EFORT launched IPSI, The Implant and Patient Safety Initiative, which starting from an inaugural workshop in 2021 issued a set of recommendations, notably through a subsequent Delphi Process involving the National Member Societies of EFORT, European Specialty Societies as well as International Experts. These recommendations provide surgeons, researchers, implant manufacturers as well as patients and health authorities with a consensus of the development, implementation, and dissemination of innovation in the field of arthroplasty. The intended key outcomes of this 1st EFORT European Consensus on “Medical & Scientific Research Requirements for the Clinical Introduction of Artificial Joint Arthroplasty Devices”are consented, practical pathways to maintain innovation and optimisation of orthopaedic products and workflows within the boundaries of MDR 2017/745. Open Access practical guidelines based on adequate, state of the art pre-clinical and clinical evaluation methodologies for the introduction of joint replacements and implant-related instrumentation shall provide hands-on orientation for orthopaedic surgeons, research institutes and laboratories, orthopaedic device manufacturers, Notified Bodies but also for National Institutes and authorities, patient representatives and further stakeholders. We would like to acknowledge and thank the Scientific Committee members, all International Expert Delegates, the Delegates from European National & Specialty Societies and the Editorial Team for their outstanding contributions and support during this EFORT European Consensus

Computer Aided Tools for the Design and Planning of Personalized Shoulder Arthroplasty

La artroplastia de hombro es el tercer procedimiento de reemplazo articular más común, después de la artroplastia de rodilla y cadera, y actualmentees el de más rápido crecimiento en el campo ortopédico. Las principales opciones quirúrgicas incluyen la artroplastia total de hombro (TSA), en la quese restaura la anatomía articular normal, y, para pacientes con un manguito rotador completamente desgarrado, la artroplastia inversa de hombro (RSA), en la que la bola y la cavidad de la articulación glenohumeral se cambian. A pesar del progreso reciente y los avances en el diseño, las tasas de complicaciones reportadas para RSA son más altas que las de la artroplastia de hombro convencional. Un enfoque específico para el paciente, en el que los médicos adaptan el tratamiento quirúrgico a las características del mismo y al estado preoperatorio, por ejemplo mediante implantes personalizados y planificación previa, puede ayudar a reducir los problemas postoperatorios y mejorar el resultado funcional. El objetivo principal de esta tesis es desarrollar y evaluar métodos novedosos para RSA personalizado, utilizando tecnologías asistidas por ordenador de última generación para estandarizar y automatizar las fases de diseño y planificación.Los implantes personalizados son una solución adecuada para el tratamiento de pacientes con pérdida extensa de hueso glenoideo. Sin embargo, los ingenieros clínicos se enfrentan a muchas variables en el diseño de implantes (número y tipo de tornillos, superficie de contacto, etc.) y una gran variabilidad anatómica y patológica. Actualmente, no existen herramientas objetivas para guiarlos a la hora de elegir el diseño óptimo, es decir, con suficiente estabilidad inicial del implante, lo que hace que el proceso de diseño sea tedioso, lento y dependiente del usuario. En esta tesis, se desarrolló una simulación de Virtual Bench Test (VBT) utilizando un modelo de elementos finitos para evaluar automáticamente la estabilidad inicial de los implantes de hombro personalizados. A través de un experimento de validación, se demostró que los ingenieros clínicos pueden utilizar el resultado de Virtual Bench Test como referencia para respaldar sus decisiones y adaptaciones durante el proceso de diseño del implante.Al diseñar implantes de hombro, el conocimiento de la morfología y la calidad ósea de la escápula en toda la población es fundamental. En particular, se tienen en cuenta las regiones con la mejor reserva ósea (hueso cortical) para definir la posición y orientación de los orificios de los tornillos, mientras se busca una fijación óptima. Como alternativa a las mediciones manuales, cuya generalización está limitada por el análisis de pequeños subconjuntos de pacientes potenciales, Statistical Shape Models (SSMs) se han utilizado comúnmente para describir la variabilidad de la forma dentro de una población. Sin embargo, estos SSMs normalmente no contienen información sobre el grosor cortical.Por lo tanto, se desarrolló una metodología para combinar la forma del hueso escapular y la morfología de la cortical en un SSM. Primero, se presentó y evaluó un método para estimar el espesor cortical, a partir de un análisis de perfil de Hounsfield Unit (HU). Luego, utilizando 32 escápulas sanas segmentadas manualmente, se creó y evaluó un modelo de forma estadística que incluía información de la cortical. La herramienta desarrollada se puede utilizar para implantar virtualmente un nuevo diseño y probar su congruencia dentro de una población virtual generada, reduciendo así el número de iteraciones de diseño y experimentos con cadáveres.Las mediciones del alargamiento de los músculos deltoides y del manguito rotador durante la planificación quirúrgica pueden ayudar a los médicos aseleccionar un diseño y una posición de implante adecuados. Sin embargo, tal evaluación requiere la indicación de puntos anatómicos como referencia para los puntos de unión de los músculos, un proceso que requiere mucho tiempo y depende del usuario, ya que a menudo se realiza manualmente. Además, las imágenes médicas, que se utilizan normalmente para la artroplastia de hombro,contienen en su mayoría solo el húmero proximal, lo que hace imposible indicarlos puntos de unión de los músculos que se encuentran fuera del campo de visión de la exploración. Por lo tanto, se desarrolló y evaluó un método totalmente automatizado, basado en SSM, para medir la elongación del deltoides y del manguito rotador. Su aplicabilidad clínica se demostró mediante la evaluación del rendimiento de la estimación automatizada de la elongación muscular para un conjunto de articulaciones artríticas del hombro utilizadas para la planificación preoperatoria de RSA, lo que confirma que es una herramienta adecuada para los cirujanos a la hora de evaluar y refinar las decisiones clínicas.En esta investigación, se dio un paso importante en la dirección de un enfoque más personalizado de la artroplastia inversa de hombro, en el que el manejo quirúrgico, es decir, el diseño y la posición del implante, se adapta a las características específicas del paciente y al estado preoperatorio. Al aplicar tecnologías asistidas por computadora en la práctica clínica, el proceso de diseño y planificación se puede automatizar y estandarizar, reduciendo así los costos y los plazos de entrega. Además, gracias a los métodos novedosos presentados en esta tesis, esperamos en el futuro una adopción más amplia del enfoque personalizado, con importantes beneficios tanto para los cirujanos como para los pacientes.Shoulder arthroplasty is the third most common joint replacement procedure, after knee and hip arthroplasty, and currently the most rapidly growing one in the orthopaedic field. The main surgical options include total shoulder arthroplasty (TSA), in which the normal joint anatomy is restored, and, for patients with a completely torn rotator cuff, reverse shoulder arthroplasty (RSA), in which the ball and the socket of the glenohumeral joint are switched. Despite the recent progress and advancement in design, the reported rates of complication for RSA are higher than those of conventional shoulder arthroplasty. A patient-specific approach, in which clinicians adapt the surgical management to patient characteristics and preoperative condition, e.g. through custom implants and pre-planning, can help to reduce postoperative problems and improve the functional outcome. The main goal of this thesis is to develop and evaluate novel methods for personalized RSA, using state-of-the-art computer aided technologies to standardize and automate the design and planning phases. Custom implants are a suitable solution when treating patients with extensive glenoid bone loss. However, clinical engineers are confronted with an enormous implant design space (number and type of screws, contact surface, etc.) and large anatomical and pathological variability. Currently, no objective tools exist to guide them when choosing the optimal design, i.e. with sufficient initial implant stability, thus making the design process tedious, time-consuming, and user-dependent. In this thesis, a Virtual Bench Test (VBT) simulation was developed using a finite element model to automatically evaluate the initial stability of custom shoulder implants. Through a validation experiment, it was shown that the virtual test bench output can be used by clinical engineers as a reference to support their decisions and adaptations during the implant design process. When designing shoulder implants, knowledge about bone morphology and bone quality of the scapula throughout a certain population is fundamental. In particular, regions with the best bone stock (cortical bone) are taken into account to define the position and orientation of the screw holes, while aiming for an optimal fixation. As an alternative to manual measurements, whose generalization is limited by the analysis of small sub-sets of the potential patients, Statistical Shape Models (SSMs) have been commonly used to describe shape variability within a population. However, these SSMs typically do not contain information about cortical thickness. Therefore, a methodology to combine scapular bone shape and cortex morphology in an SSM was developed. First, a method to estimate cortical thickness, starting from a profile analysis of Hounsfield Unit (HU), was presented and evaluated. Then, using 32 manually segmented healthy scapulae, a statistical shape model including cortical information was created and assessed. The developed tool can be used to virtually implant a new design and test its congruency inside a generated virtual population, thus reducing the number of design iterations and cadaver labs. Measurements of deltoid and rotator cuff muscle elongation during surgical planning can help clinicians to select a suitable implant design and position. However, such an assessment requires the indication of anatomical landmarks as a reference for the muscle attachment points, a process that is time-consuming and user-dependent, since often performed manually. Additionally, the medical images, which are normally used for shoulder arthroplasty, mostly contain only the proximal humerus, making it impossible to indicate those muscle attachment points which lie outside of the field of view of the scan. Therefore, a fully-automated method, based on SSM, for measuring deltoid and rotator cuff elongation was developed and evaluated. Its clinical applicability was demonstrated by assessing the performance of the automated muscle elongation estimation for a set of arthritic shoulder joints used for preoperative planning of RSA, thus confirming it a suitable tool for surgeons when evaluating and refining clinical decisions. In this research, a major step was taken into the direction of a more personalized approach to Reverse Shoulder Arthroplasty, in which the surgical management, i.e. implant design and position, is adapted to the patient-specific characteristics and preoperative condition. By applying computer aided technologies in the clinical practice, design and planning process can be automated and standardized, thus reducing costs and lead times. Additionally, thanks to the novel methods presented in this thesis, we expect in the future a wider adoption of the personalized approach, with important benefits both for surgeons and patients.<br /

Modelo de sistema de soporte a la diagnosis de trastornos osteoarticulares de miembros inferiores utilizando procesamiento de imágenes de rayos X

Los trastornos osteoarticulares aquejan a personas de todas las regiones del mundo sin distinción, ejemplos de ellas son: la osteoporosis y atrosis. La OMS determina la existencia de un incremento de casos en sociedades socioeconómicas más bajas y la Unión Europea establece una estrategia enfocada a entregar salud personalizada en el momento correcto, y brindar una alternativa de prevención oportuna y especifica denominada (PerMed). En este contexto nuestro país necesita aplicar la Medicina Personalizada para diagnosticar a tiempo enfermedades con alta incidencia. La presente investigación busca alinearse a los objetivos de la Medicina Personalizada proporcionando un modelo de sistema de soporte a la diagnosis de trastornos osteoarticulares de miembros inferiores utilizando procesamiento de imágenes de rayos X, teniendo presente la confidencialidad y protección de los datos. El pre-procesamiento de las imágenes de rayos X, permitió eliminar los desafíos de estas imágenes, y posibilito la generación de un gold-standard que sirvió como guía para la segmentación-registro de las estructuras óseas de miembros inferiores. Se utilizaron los modelos estadísticos como: SSM - Statistical Shape Model, SAM – Statistical Appeareance Model, ASM - Active Shape Model y Gradient Profiling en el refinamiento de la etapa de segmentación-registro como parte del entrenamiento y prueba. Estos modelos han sido validados con artículos de investigación presentados en el Capítulo IV con resultados de precisión en la segmentación entre el 74 % y 83 % y para la clasificación de las estructuras óseas dependiendo del objetivo a resolver sea: a) detectar fracturas en el acetábulo, o b) detectar osteoporosis en el fémur proximal, los resultados obtuvieron una precisión de: 73% y 87% respectivamente; y por ultimo para lograr el objetivo de: c) medir la distancia articular, se obtiene un error promedio equivalente a 2.4 px, este es un error aceptable para respaldar el diagnostico de desgaste articular de cadera llamado "osteoartritis de cadera". Asimismo, hubo una mejora significativa en el tiempo de procesamiento comparado con la literatura analizada

Book of Abstracts 15th International Symposium on Computer Methods in Biomechanics and Biomedical Engineering and 3rd Conference on Imaging and Visualization

In this edition, the two events will run together as a single conference, highlighting the strong connection with the Taylor & Francis journals: Computer Methods in Biomechanics and Biomedical Engineering (John Middleton and Christopher Jacobs, Eds.) and Computer Methods in Biomechanics and Biomedical Engineering: Imaging and Visualization (JoãoManuel R.S. Tavares, Ed.). The conference has become a major international meeting on computational biomechanics, imaging andvisualization. In this edition, the main program includes 212 presentations. In addition, sixteen renowned researchers will give plenary keynotes, addressing current challenges in computational biomechanics and biomedical imaging. In Lisbon, for the first time, a session dedicated to award the winner of the Best Paper in CMBBE Journal will take place. We believe that CMBBE2018 will have a strong impact on the development of computational biomechanics and biomedical imaging and visualization, identifying emerging areas of research and promoting the collaboration and networking between participants. This impact is evidenced through the well-known research groups, commercial companies and scientific organizations, who continue to support and sponsor the CMBBE meeting series. In fact, the conference is enriched with five workshops on specific scientific topics and commercial software.info:eu-repo/semantics/draf