Integrating Learning And Visualization Technologies In Orthopaedics:- Establishing The Virtual Orthopaedic European University

Digital technologies offer a working environment for familiarisation with new surgical procedures and management of clinical case audit. Our aim is to provide a novel route for access to educational material that more closely resembles the working practice of the arthroscopist. This is to support higher surgical training and life long learning. The proof of concept has been the development of a shoulder arthroscopy simulation model as an interface for the surgical trainee to access multimedia based educational orthopaedic modules. This demonstrates a human-computer interface that more closely resembles the process of factual knowledge association during clinical procedures, moving toward the ultimate goal of seamless integration of knowledge repositories with clinical intervention operative video information, integrating the structured surgical course model with the multimedia educational orthopaedic modules, generated for the learning of shoulder surgery

A Virtual University Infrastructure For Orthopaedic Surgical Training With Integrated Simulation

This thesis pivots around the fulcrum of surgical, educational and technological factors. Whilst there is no single conclusion drawn, it is a multidisciplinary thesis exploring the juxtaposition of different academic domains that have a significant influence upon each other. The relationship centres on the engineering and computer science factors in learning technologies for surgery. Following a brief introduction to previous efforts developing surgical simulation, this thesis considers education and learning in orthopaedics, the design and building of a simulator for shoulder surgery. The thesis considers the assessment of such tools and embedding into a virtual learning environment. It explains how the performed experiments clarified issues and their actual significance. This leads to discussion of the work and conclusions are drawn regarding the progress of integration of distributed simulation within the healthcare environment, suggesting how future work can proceed

A virtual university infrastructure for orthopaedic surgical training with integrated simulation

This thesis pivots around the fulcrum of surgical, educational and technological factors. Whilst there is no single conclusion drawn, it is a multidisciplinary thesis exploring the juxtaposition of different academic domains that have a significant influence upon each other. The relationship centres on the engineering and computer science factors in learning technologies for surgery. Following a brief introduction to previous efforts developing surgical simulation, this thesis considers education and learning in orthopaedics, the design and building of a simulator for shoulder surgery. The thesis considers the assessment of such tools and embedding into a virtual learning environment. It explains how the performed experiments clarified issues and their actual significance. This leads to discussion of the work and conclusions are drawn regarding the progress of integration of distributed simulation within the healthcare environment, suggesting how future work can proceed.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

The value of medical 3D printing : hope versus hype

3D printing has been growing fast in the medical field. While preliminary clinical results have been reported in the literature, it’s health economic value has not been analyzed yet. Medical 3D printing has found its main applications in surgery; especially orthopedics and reconstructive surgery. Its applications rage from anatomic models to surgical guides and implants. All of these can be seen as consecutive levels of integration. While papers often report improved clinical results, a great accuracy and an acceptable price, few of these are backed with numbers. We performed 3 health economic analyses using Markov models using a payer perspective on each of these 3 levels of integration. As a first level, we analyzed the impact of using anatomic models as a tool for surgical planning in congenital heart diseases for 9 different procedures. Results varied from not being cost effective for atrial septum defects, to being highly cost-effective in highly complex procedures such as a Norwood repair. Second, we analyzed the already well integrated use of surgical guides for primary total knee arthroplasty using Belgian registry data. The database approach showed an significantly reduced revision rate in the group using custom guides compared to the conventional approach. The Markov models showed the technology to be cost-effective if CT-based guides are used. At last, we analyzed the use of custom 3D printed acetabular implants for revision surgery in patients with acetabular defects compared to non-3D printed custom implants. The 3D printed implants showed to be cost effective, especially in younger patients. The final chapter gives an overview of the pitfalls encountered during these preliminary analyses and gives a glance at possible solutions to allow better analysis and faster adoption of medical innovations

Machine learning and interactive real-time simulation for training on relevant total hip replacement skills.

Virtual Reality simulators have proven to be an excellent tool in the medical sector to help trainees mastering surgical abilities by providing them with unlimited training opportunities. Total Hip Replacement (THR) is a procedure that can benefit significantly from VR/AR training, given its non-reversible nature. From all the different steps required while performing a THR, doctors agree that a correct fitting of the acetabular component of the implant has the highest relevance to ensure successful outcomes. Acetabular reaming is the step during which the acetabulum is resurfaced and prepared to receive the acetabular implant. The success of this step is directly related to the success of fitting the acetabular component. Therefore, this thesis will focus on developing digital tools that can be used to assist the training of acetabular reaming. Devices such as navigation systems and robotic arms have proven to improve the final accuracy of the procedure. However, surgeons must learn to adapt their instrument movements to be recognised by infrared cameras. When surgeons are initially introduced to these systems, surgical times can be extended up to 20 minutes, maximising surgical risks. Training opportunities are sparse, given the high investment required to purchase these devices. As a cheaper alternative, we developed an Augmented Reality (AR) alternative for training on the calibration of imageless navigation systems (INS). At the time, there were no alternative simulators that using head-mounted displays to train users into the steps to calibrate such systems. Our simulator replicates the presence of an infrared camera and its interaction with the reflecting markers located on the surgical tools. A group of 6 hip surgeons were invited to test the simulator. All of them expressed their satisfaction with the ease of use and attractiveness of the simulator as well as the similarity of interaction with the real procedure. The study confirmed that our simulator represents a cheaper and faster option to train multiple surgeons simultaneously in the use of Imageless Navigation Systems (INS) than learning exclusively on the surgical theatre. Current reviews on simulators for orthopaedic surgical procedures lack objective metrics of assessment given a standard set of design requirements. Instead, most of them rely exclusively on the level of interaction and functionality provided. We propose a comparative assessment rubric based on three different evaluation criteria. Namely immersion, interaction fidelity, and applied learning theories. After our assessment, we found that none of the simulators available for THR provides an accurate interactive representation of resurfacing procedures such as acetabular reaming based on force inputs exerted by the user. This feature is indispensable for an orthopaedics simulator, given that hand-eye coordination skills are essential skills to be trained before performing non-reversible bone removal on real patients. Based on the findings of our comparative assessment, we decided to develop a model to simulate the physically-based deformation expected during traditional acetabular reaming, given the user’s interaction with a volumetric mesh. Current interactive deformation methods on high-resolution meshes are based on geometrical collision detection and do not consider the contribution of the materials’ physical properties. By ignoring the effect of the material mechanics and the force exerted by the user, they become inadequate for training on hand- eye coordination skills transferable to the surgical theatre. Volumetric meshes are preferred in surgical simulation to geometric ones, given that they are able to represent the internal evolution of deformable solids resulting from cutting and shearing operations. Existing numerical methods for representing linear and corotational FEM cuts can only maintain interactive framerates at a low resolution of the mesh. Therefore, we decided to train a machine-learning model to learn the continuum mechanic laws relevant to acetabular reaming and predict deformations at interactive framerates. To the best of our knowledge, no research has been done previously on training a machine learning model on non-elastic FEM data to achieve results at interactive framerates. As training data, we used the results from XFEM simulations precomputed over 5000 frames for plastic deformations on tetrahedral meshes with 20406 elements each. We selected XFEM simulation as the physically-based deformation ground-truth given its accuracy and fast convergence to represent cuts, discontinuities and large strain rates. Our machine learning-based interactive model was trained following the Graph Neural Networks (GNN) blocks. GNNs were selected to learn on tetrahedral meshes as other supervised-learning architectures like the Multilayer perceptron (MLP), and Convolutional neural networks (CNN) are unable to learn the relationships between entities with an arbitrary number of neighbours. The learned simulator identifies the elements to be removed on each frame and describes the accumulated stress evolution in the whole machined piece. Using data generated from the results of XFEM allowed us to embed the effects of non-linearities in our interactive simulations without extra processing time. The trained model executed the prediction task using our tetrahedral mesh and unseen reamer orientations faster per frame than the time required to generate the training FEM dataset. Given an unseen orientation of the reamer, the trained GN model updates the value of accumulated stress on each of the 20406 tetrahedral elements that constitute our mesh during the prediction task. Once this value is updated, the tetrahedrons to be removed from the mesh are identified using a threshold condition. After using each single-frame output as input for the following prediction repeatedly for up to 60 iterations, our model can maintain an accuracy of up to 90.8% in identifying the status of each element given their value of accumulated stress. Finally, we demonstrate how the developed estimator can be easily connected to any game engine and included in developing a fully functional hip arthroplasty simulator

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

The impact of AI on radiographic image reporting – perspectives of the UK reporting radiographer population

Background: It is predicted that medical imaging services will be greatly impacted by AI in the future. Developments in computer vision have allowed AI to be used for assisted reporting. Studies have investigated radiologists' opinions of AI for image interpretation (Huisman et al., 2019 a/b) but there remains a paucity of information in reporting radiographers' opinions on this topic.Method: A survey was developed by AI expert radiographers and promoted via LinkedIn/Twitter and professional networks for radiographers from all specialities in the UK. A sub analysis was performed for reporting radiographers only.Results: 411 responses were gathered to the full survey (Rainey et al., 2021) with 86 responses from reporting radiographers included in the data analysis. 10.5% of respondents were using AI tools? as part of their reporting role. 59.3% and 57% would not be confident in explaining an AI decision to other healthcare practitioners and 'patients and carers' respectively. 57% felt that an affirmation from AI would increase confidence in their diagnosis. Only 3.5% would not seek second opinion following disagreement from AI. A moderate level of trust in AI was reported: mean score = 5.28 (0 = no trust; 10 = absolute trust). 'Overall performance/accuracy of the system', 'visual explanation (heatmap/ROI)', 'Indication of the confidence of the system in its diagnosis' were suggested as measures to increase trust.Conclusion: AI may impact reporting professionals' confidence in their diagnoses. Respondents are not confident in explaining an AI decision to key stakeholders. UK radiographers do not yet fully trust AI. Improvements are suggested

An evaluation of a training tool and study day in chest image interpretation

Background: With the use of expert consensus a digital tool was developed by the research team which proved useful when teaching radiographers how to interpret chest images. The training tool included A) a search strategy training tool and B) an educational tool to communicate the search strategies using eye tracking technology. This training tool has the potential to improve interpretation skills for other healthcare professionals.Methods: To investigate this, 31 healthcare professionals i.e. nurses and physiotherapists, were recruited and participants were randomised to receive access to the training tool (intervention group) or not to have access to the training tool (control group) for a period of 4-6 weeks. Participants were asked to interpret different sets of 20 chest images before and after the intervention period. A study day was then provided to all participants following which participants were again asked to interpret a different set of 20 chest images (n=1860). Each participant was asked to complete a questionnaire on their perceptions of the training provided. Results: Data analysis is in progress. 50% of participants did not have experience in image interpretation prior to the study. The study day and training tool were useful in improving image interpretation skills. Participants perception of the usefulness of the tool to aid image interpretation skills varied among respondents.Conclusion: This training tool has the potential to improve patient diagnosis and reduce healthcare costs

Hip deformities and femoroacetabular impingement

RESUMO: Conceptualmente, a conservação de uma estrutura anatómica é mais benéfica do que a sua substituição. No caso das articulações humanas, este conceito é particularmente importante face aos múltiplos problemas, ainda não resolvidos, relacionados com próteses e materiais usados na cirurgia ortopédica. Na articulação coxofemoral, o conceito de preservação, melhorando os parâmetros biomecânicos, assume uma complexidade técnica acrescida maioritariamente pelo facto de a circulação epifisária do fémur ser intra-articular e dada a proximidade de importantes estruturas neurovasculares. O conflito femoroacetabular (CFA) e a displasia acetabular no adulto jovem, são duas entidades patológicas comuns embora com múltiplas áreas ainda por investigar. A displasia infantil, não diagnosticada e não tratada, pode originar displasia acetabular residual na idade adulta e consequente sintomatologia e limitação funcional. O diagnóstico de CFA no adulto é baseado em critérios clínicos e radiográficos. Clinicamente apresenta-se igualmente com dor e limitação funcional. Radiologicamente, dois subtipos de CFA são habitualmente reconhecidos, o tipo Cam (mecanismo patológico decorrente de asfericidade femoral) e o tipo Pincer (por hipercobertura acetabular). Embora com padrões diferentes de envolvimento articular, os dois mecanismos de conflito condicionam dor, lesão estrutural do labrum e condropatia. Atualmente, a morfologia Cam é considerada como um dos principais fatores de risco morfológico que contribuem para o desenvolvimento de osteoartrose precoce da coxofemoral, eventualmente com necessidade de recurso a prótese total da anca. Apesar de a investigação inicial na área da cirurgia conservadora da anca ter documentado bons resultados cirúrgicos, atualmente a controvérsia é francamente superior ao consenso relativamente à melhor abordagem diagnóstica e terapêutica. Caracteristicamente, apesar de em muitos casos os achados clínicos e radiológicos serem inequívocos para o diagnóstico de CFA, um número substancial de doentes apresenta achados frustes ou equívocos. Por outro lado, múltiplos estudos descreveram uma alta prevalência de morfologia compatível com CFA na população adulta e em indivíduos saudáveis assintomáticos. Atualmente, não existe uma ferramenta de imagem ideal que facilite a alocação fidedigna de todos os doentes a um grupo patológico específico ou, por outro lado, exclua com confiança o diagnóstico de conflito. No entanto, os parâmetros de imagem podem ser utilizados para analisar e descrever as diferentes características morfológicas da anca e adicionalmente confirmar o diagnóstico de CFA. Esta tese enfoca, por um lado, a avaliação da morfologia coxofemoral em diferentes populações, investigando quais articulações estão mais predispostas ao desenvolvimento de sintomas e, por outro, os resultados do tratamento cirúrgico de uma coorte com o diagnóstico de CFA tipo Cam. Especificamente, a investigação efetuada: 1) examinou características morfológicas específicas da coxofemoral em diferentes populações (sintomáticas ou não sintomáticas); 2) desenhou um modelo estatístico baseado em preditores anatómicos no sentido de estabelecer as articulações em risco de desenvolvimento sintomático, incorporando geometrias articulares específicas e parâmetros espinhopélvicos; e 3) analisou os resultados de terapêutica cirúrgica numa coorte de doentes com o diagnóstico CFA tipo Cam. Durante a progressão clínica na área da imagiologia e nesta área patológica em particular, apercebemo-nos da existência de múltiplas lacunas de conhecimento que procurámos colmatar com a investigação agora publicada e descrita nesta tese. A sistematização por capítulos reflete precisamente a necessidade de abordar a questão em áreas de conhecimento, simultaneamente distintas e complementares. Os seis capítulos desta tese abrangem o espectro clínico desde o diagnóstico até ao tratamento da anca jovem. De modo a apresentar os objetivos desta tese numa sequência lógica, desde a anatomia geral até à morfologia e tratamento específicos do CFA, a análise da anca assintomática será descrita em primeiro lugar seguida pela análise da relação anatomoclínica entre morfologia articular e sintomas. Por último será abordada a terapêutica do doente sintomático. Na PARTE I, apresentamos os tópicos essenciais para compreender a abrangência do espectro da presente tese, designadamente a relevância e a contemporaneidade do tema “CFA” e adicionalmente o enquadramento anatómico, morfológico e vascular desta articulação. O Capítulo 1 é dedicado ao desenvolvimento e morfogénese da anca. No Capítulo 2, sublinhamos a importância e o papel da imagem através de uma revisão enfocada nas perspetivas atuais e futuras sobre este tópico (Artigo I). No Capítulo 3, realizamos uma revisão sistemática da literatura no sentido de descrever o estado da arte com foco na prevalência da morfologia de CFA em populações assintomáticas e sintomáticas. Este capítulo destaca as múltiplas lacunas de conhecimento relativas ao papel da morfologia da articulação coxofemoral na patogénese do CFA (Artigo II). Com base nesta parte introdutória, abordamos seguidamente os objetivos da presente tese, gerais e específicos, na PARTE II.Na PARTE III, descrevemos o corpo da investigação clínica original efetuada. O Capítulo 4 é dedicado à caracterização detalhada da morfologia da anca, designadamente óssea e vascular. A morfologia coxofemoral foi quantificada utilizando software com capacidade de semi-automatização analítica, permitindo estudar a prevalência e relação entre as diferentes morfologias articulares e o género, dominância e simetria articular (Artigo III). A morfologia Cam foi ainda alvo de caracterização mais aprofundada, através do desenvolvimento de um novo parâmetro quantitativo com potencialidade diagnóstica e de planeamento cirúrgico/ /prognóstico, primariamente testado numa coorte assintomática (Artigo IV) e seguidamente também em doentes com indicação cirúrgica (Artigo V). Na nossa atividade clínica diária apreciámos a necessidade urgente de melhor caracterizar a topografia da deformidade Cam e a respetiva relação com as artérias nutritivas da epífise femoral. A impressão clínica referida sugeria que a morfologia Cam frequentemente se estendia posteriormente ao quadrante póstero-superior, intersectando a região retinacular vascular. No entanto, por imagem a natureza arterial destas estruturas nunca havia sido confirmada. Por esta razão, a importância do parâmetro mencionado foi sublinhada e comprovada no estudo cadavérico com avaliação topográfica vascular do fémur proximal (Artigo VI). No Capítulo 5 testámos múltiplos parâmetros imagiológicos e respetivas variações/relações com diferentes morfologias coxofemorais, no sentido de identificar as articulações com risco clínico aumentado de desenvolvimento sintomático. Para este fim efetuámos estudos baseados em computação avançada com modelação estatística (Artigo VII) e também em ressonância magnética (RM) tridimensional (Artigo VIII). O Capítulo 6 descreve as opções de tratamento (Artigo IX) e os resultados clínicos num estudo clínico de uma coorte com follow-up mínimo de 2 anos, comparando a abordagem cirúrgica aberta e artroscópica (Artigo X). Os resultados dos diferentes capítulos estão sumarizados na PARTE IV, onde apresentamos a síntese geral, a discussão crítica dos resultados obtidos à luz da literatura atual e finalmente as conclusões relevantes. As oportunidades futuras de investigação são igualmente abordadas neste capítulo. Em resumo o trabalho constante da presente tese sugere: Primeiro, que a avaliação imagiológica detalhada da morfologia coxofemoral é essencial no sentido de compreender aprofundadamente não só a própria articulação como também a morfologia pélvica (Artigo I). Segundo, paradoxalmente, a definição clínica de um caso patológico e das diferentes entidades relacionadas, é ainda inexistente. Os parâmetros quantitativos e qualitativos que comummente estão associados com CFA tipo Pincer e Cam são francamente frequentes em diferentes populações (sintomáticas e assintomáticas) (Artigo II).Terceiro, em populações assintomáticas adultas, os intervalos de referência específicos para os parâmetros quantitativos associados a morfologia de CFA e displasia são mais latos e com limites superiores mais elevados do que os atualmente utilizados na prática clínica (Artigo III). A morfologia femoral bem como os epicentros/magnitudes das deformidades Cam são específicos de género, observando-se maiores valores de ângulo alfa e ómega em indivíduos do sexo masculino (Artigo IV). Quarto, é frequente a interseção entre a extensão póstero-superior da deformidade Cam e a convergência epifisária das estruturas vasculares retinaculares observadas em RM, aspetos que se revestem de primordial importância no planeamento cirúrgico. Adicionalmente a extensão radial da deformidade Cam (ângulo ómega) está significativamente mais relacionada com a sintomatologia clínica pré-cirúrgica do que o parâmetro mais comummente utilizado na prática clínica (ângulo alfa) (Artigo V). A origem das estruturas vasculares observadas por RM na prega retinacular é inequivocamente arterial, sendo que abrange uma extensão mais anterior do que classicamente assumido (Artigo VI). Quinto, as geometrias ovalares (em detrimento das morfologias esféricas e elipsoides) são melhor representativas de ambas as superfícies articulares da coxofemoral, designadamente do fémur e acetábulo, bem como das ancas sintomáticas que clinicamente exibem sinais de CFA (Pincer, Cam e misto) (Artigo VII). Indivíduos com maiores deformidades Cam, aspetos de hipocobertura acetabular e acentuação da anteflexão pélvica apresentam uma maior probabilidade de desenvolverem sintomas articulares (Artigo VIII). Esta observação é crítica, dado que fornece, na prática clínica, informação essencial acerca da potencial predisposição para fenómenos de exacerbação sintomática futura, permitindo desta forma instituição de medidas terapêuticas/preventivas adequadas. Na perspetiva do doente, um diagnóstico precoce e preciso, pode conceptualmente prevenir, numa primeira fase, alterações condropáticas articulares e, numa segunda instância, progressão para artrose estabelecida. Sexto, documentamos resultados clínicos e funcionais significativamente favoráveis quando comparamos a abordagem artroscópica e aberta no tratamento cirúrgico da deformidade Cam, sendo de observar que o género feminino está associado a menor score funcional na avaliação pré-operatória (Artigos IX e X). Futuramente, a imagiologia e a cirurgia conservadora da anca irão desenvolver-se conjuntamente e em paralelo com novos e maiores desafios. A descrição de novos parâmetros analíticos para avaliação da patoanatomia coxofemoral, associada à inovação tecnológica crescente e à implementação da inteligência artificial, impõem uma evolução clínica oposta à assunção de classificações patológicas demasiadamente simplistas. Nesse sentido a existência de guidelines de diagnóstico e terapêutica mais efetivas e baseadas na evidência, que nos levem além da pura diferenciação entre CFA e displasia, são urgentes. A história natural das deformidades Cam e Pincer, sintomáticas ou assintomáticas, é ainda grandemente desconhecida, assumindo-se como uma área determinante de investigação no que concerne ao diagnóstico, terapêutica e prognóstico.ABSTRACT: Conceptually, the preservation of a human anatomical structure makes more sense than its replacement. This concept is even more striking in the case of human joints due to the multitude of unsolved problems related to implants used in orthopaedic surgery. With respect to the hip, joint preservation assumes an increased technical complexity when compared to other joints; this is due to two main reasons: the intra-articular epiphyseal circulation of the femur and the proximity of large neurovascular structures. Femoroacetabular impingement (FAI) and acetabular dysplasia (DHD) in young adults are two common but poorly characterised pathological entities. If undiagnosed and untreated, dysplasia in childhood may lead to residual DHD in young adults, as diagnosed on radiographs, and may also give rise to symptoms such as hip pain and restricted range of motion. The diagnosis of FAI in adults is based on clinical and imaging criteria. The most frequently noticed symptoms of FAI include hip pain and restricted function. Radiologically, two main subtypes of FAI are recognised: The Cam-type, with the pathoanatomical mechanism located on the femoral side, and the Pincertype on the acetabular side. Although with different pathological patterns, both types cause pain and articular damage of the labrum and cartilage. While Cam-type FAI is believed to be a major contributing factor to the early onset of hip osteoarthritis (OA), which eventually requires a total hip replacement, the relationship of other shapes and morphologies with OA are still under debate. Despite the initial promising reports on outcomes following surgical management of these conditions, the best approach to diagnose and manage them still remains controversial. Although for some patients there are unambiguous clinical and imaging findings of FAI, for a substantial number of patients there are minimal or intermediate findings. Moreover, several studies have reported a high prevalence of FAI morphology among the “normal” population and in asymptomatic healthy individuals. At present, there is no adequate imaging tool to facilitate the reliable allocation of all patients into the correct diagnostic group or to confidently rule out diagnosis. However, imaging parameters can be used to describe different hip morphological characteristics and additionally confirm or preclude the diagnosis of FAI.This thesis focuses on assessing hip morphology in different populations by investigating which specific joints are more prone to developing symptoms and by evaluating treatment outcomes of a FAI cohort. Specifically, this research concentrates on the following: 1) examining population-specific (symptomatic and non-symptomatic) characteristics of hip morphology; 2) developing an anatomic-based model to establish “at-risk” hip joints, incorporating subject-specific hip geometries and spinopelvic parameters and 3) investigating treatment outcomes in a Cam-type FAI cohort. In our clinical progression in imaging and in this particular area of pathology, we became aware of the existence of several gaps that we sought to fill with the now published research hereby described. The systematisation by chapters precisely reflects the need to address the issue in simultaneously distinct and complementary areas of knowledge. This thesis consists of six chapters, which cover the entire spectrum from the diagnosis to treatment of the young hip. To present the aims of this thesis in a sequential manner from general morphology to more specific FAI-related topics, the analysis of the asymptomatic hip will be presented first, followed by how joint morphology is associated with symptoms and, finally, will conclude with treatment. In PART I, we introduce the topics that are relevant to understand the full scope of our thesis; we aim to accomplish this by addressing the relevance and contemporariness of the “FAI” theme and by describing the general and vascular anatomy of the hip. Chapter 1 is devoted to hip development and morphogenesis. In Chapter 2, we address the importance of imaging by conducting a thorough review of current and future perspectives on this topic (Paper I). In Chapter 3, we perform a systematic review of the literature to write a state-of-the-art overview, focussing on asymptomatic and symptomatic FAI morphology prevalence and highlighting the multiple gaps in knowledge regarding the role of hip morphology in the pathogenesis of FAI (Paper II). Building on the first part, we address the rationale and aims of this thesis in PART II. In PART III, we describe the original research that was performed and published. Chapter 4 focusses on the detailed characterisation of hip morphology, both osseous and vascular. Bony hip morphology was quantified using a semi-automated software, which allows to robustly study in detail shape variants in an asymptomatic population and their relationship with sex, side and limb dominance (Paper III). Cam morphology was further defined by developing a novel quantitative parameter, with diagnostic and treatment planning capabilities using a cohort of both asymptomatic individuals (Paper IV) and patients undergoing surgery (Paper V). Moreover, we felt the need to better characterise the topography of the deformity and its relationship with the nourishing arteries of the femoral head, as Cam morphology frequently has a posterior a bstr extension that overlaps the retinacular vascular structures. However, its arterial origin has never been described or confirmed in the literature. For this reason, the importance of the aforementioned parameter has been outlined by the cadaveric arterial topographic study of the proximal femur (Paper VI). In Chapter 5, we test multiple parameters and their associated shape variants to detect which ones allow identifying a risk-increased joint in various populations. To this end, we use both advanced computing for shape modelling (Paper VII) and three dimensional (3D) magnetic resonance imaging (MRI) (Paper VIII). Chapter 6 describes the various treatment options (Paper IX) and outcomes in a cohort clinical study, comparing open surgery with arthroscopic surgery in terms of treating Cam deformities (Paper X). The results of the aforementioned chapters are summarised in PART IV, presenting the general synthesis, discussing the results in the light of current literature and detailing the conclusions of this thesis. The scope of potential future research within this field is also presented in this chapter. In brief, this thesis suggests the following: First, detailed imaging assessment of hip morphology is paramount to better understanding both the hip joint and pelvic morphology (Paper I). Second, the case definitions of different morphologies and clinical entities are missing as far as FAI and related disorders are concerned. Qualitative and quantitative radiographic findings thought to be associated with Cam- and Pincer-type FAI, as well as the coexistence between them, are quite common among different populations (Paper II). Third, in adult asymptomatic populations, sex-specific reference intervals for hip measurements for DHD and FAI morphology are wider than currently accepted values (Paper III). Moreover, femoral morphology with distinct Cam magnitudes and epicentres is also sex-specific, with higher mean alpha angle (α°) and omega angle (Ω°) values seen in males (Paper IV). Forth, Cam deformity frequently overlaps with the retinacular vascular structures seen in an MRI; this finding has practical surgical relevance. Additionally, the radial extension of the Cam deformity (Ω°) is more significantly associated with the patients’ symptoms prior to surgery than the α° (paper V). The origin of the vascular structures seen in the retinacular fold is unequivocally arterial in nature, and these structures have a more anterior distribution than classically assumed (Paper VI). Fifth, ovoid geometries are more representative of both articular surfaces of the hip joint as well as of Cam, Pincer and mixed impinged hips when compared to spherical or ellipsoidal shapes (Paper VII). Individuals with larger Cam deformities, decreased acetabular coverage and increased pelvic anteflexion are more likely to experience hip symptoms (Paper VIII). This provides clinicians with indications of how the pathology exacerbates, allowing them to perform the correct clinical assessments and proceed with the correct form of care. From a patient’s perspective, an early and accurate diagnosis could prevent cartilage degradation and progression to OA. Sixth, similar outcomes and significant functional improvement are observed when comparing open and arthroscopic surgery in the treatment of Cam deformities (follow-up time of two years). It should be noted that the female gender was associated with poor hip function in the preoperative evaluation (papers IX and X). Looking ahead, imaging and hip preserving surgery (HPS) will evolve hand-in-hand in the face of new and greater challenges. The increasing number of analytic parameters describing hip joint pathomorphologies as well as new sophisticated 3D imaging-analysis together with emerging artificial intelligence-based technologies have transported us beyond simple classification systems. Moreover, more reliable diagnostic and treatment guidelines that go beyond differentiation into pure FAI and dysplasia are paramount. The largely unknown natural course of both hips with symptomatic FAI and asymptomatic individuals continues to present research opportunities as far as diagnosis, treatment and prognosis are concerned

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