As progressivas inovações tecnológicas, na área de projeto mecânico, contribuem para a adoção de novos procedimentos cirúrgicos relacionados à ortopedia. Este trabalho trata do projeto, desenvolvimento e fabricação de dispositivos de usinagem e instrumentais cirúrgicos para aplicação em cirurgias de recapeamento da cabeça femoral em humanos e animais, buscando aperfeiçoar tal procedimento no que diz respeito a tecnologias voltadas à modelagem óssea e furação centralizada com a cabeça femoral. Nesse contexto, a relação tempo x precisão foi muito bem explorada, de forma a auxiliar com eficiência os cirurgiões e os pacientes que necessitam dessa cirurgia reduzindo a interferência da habilidade do cirurgião no resultado final da cirurgia. A fresa multilaminar sequencial, criada para usinar a cabeça femoral conforme geometria interna da prótese de recapeamento de quadril é uma importante ferramenta para redução do tempo de cirurgia, uma vez que é necessária a troca de ferramentas durante os procedimentos cirúrgicos como mostrado nesta tese. O instrumental cirúrgico, responsável para o funcionamento correto desses dispositivos de usinagem, é um guia de furação personalizado capaz de alinhar a broca e a fresa durante a modelagem da cabeça femoral, de acordo com o ângulo do colo femoral de cada paciente. Assim, este trabalho trata da concepção, desenvolvimento e fabricação de protótipos de um dispositivo de usinagem e instrumentais cirúrgicos que promovam a usinagem centralizada seguindo o ângulo do colo femoral, redução do tempo de cirurgia e da aplicação cirúrgica com prótese de recapeamento artroplastia de recapeamento canina. Os produtos desenvolvidos nesse trabalho serão nomeados como \"fresa multilaminar sequencial\", \"máscara para furação centralizada\" e \"prótese e instrumentais cirúrgicos para cães\", para a artroplastia de recapeamento de quadril. Com os desenvolvimentos, é esperada uma redução no tempo da cirurgia, bem como um aumento na segurança, possibilitando maior sucesso nesses procedimentos em humanos, bem como trás nova tecnologia para a medicina veterinária. / Progressive technological innovations in the area of mechanical design, contribute to the adoption of new surgical procedures related to orthopedics. This work addresses the design development and manufacture of machining devices and surgical instruments to be used in resurfacing surgeries of the femoral head in humans and animals, seeking to improve this procedure in regards to a new technology related to bone structure for machining and drilling aligned with the femoral head. In this context, the relation time c accuracy was very well explored, in order to assist with efficiency surgeons and patients requiring surgery that reduces the interference on the skill of the surgeon on the surgery outcome. The simultaneous development of the multilaminar-mill, designed to machine the femoral head matching the internal geometry of the resurfacing prosthesis is an important tool for reducing the surgery time, as the tool changes during surgery as shown this thesis. The surgical instrument responsible for the proper operation of these machining devices is a customized guide drill mark capable of aligning the drill and the mill during drilling and milling of the femoral head, according to the angle of the femoral neck of each patient. This work deals with the design, development and manufacturing of a machining device prototype and surgical instruments to promote the centralized machining following the angle of the femur neck the reduction of surgery time and the innovate arthroplasty surgery in humans animals. The products developed in this work are named as \"sequential multilaminar mill\", \"drilling centering mask\" and \"prosthesis and instrumental for dogs\", for hip resurfacing arthroplasty. With the developments, it is expected to reduce the surgical time, as well increasing safety, allowing greater success in these procedures.

As progressivas inovações tecnológicas, na área de projeto mecânico, contribuem para a adoção de novos procedimentos cirúrgicos relacionados à ortopedia. Este trabalho trata do projeto, desenvolvimento e fabricação de dispositivos de usinagem e instrumentais cirúrgicos para aplicação em cirurgias de recapeamento da cabeça femoral em humanos e animais, buscando aperfeiçoar tal procedimento no que diz respeito a tecnologias voltadas à modelagem óssea e furação centralizada com a cabeça femoral. Nesse contexto, a relação tempo x precisão foi muito bem explorada, de forma a auxiliar com eficiência os cirurgiões e os pacientes que necessitam dessa cirurgia reduzindo a interferência da habilidade do cirurgião no resultado final da cirurgia. A fresa multilaminar sequencial, criada para usinar a cabeça femoral conforme geometria interna da prótese de recapeamento de quadril é uma importante ferramenta para redução do tempo de cirurgia, uma vez que é necessária a troca de ferramentas durante os procedimentos cirúrgicos como mostrado nesta tese. O instrumental cirúrgico, responsável para o funcionamento correto desses dispositivos de usinagem, é um guia de furação personalizado capaz de alinhar a broca e a fresa durante a modelagem da cabeça femoral, de acordo com o ângulo do colo femoral de cada paciente. Assim, este trabalho trata da concepção, desenvolvimento e fabricação de protótipos de um dispositivo de usinagem e instrumentais cirúrgicos que promovam a usinagem centralizada seguindo o ângulo do colo femoral, redução do tempo de cirurgia e da aplicação cirúrgica com prótese de recapeamento artroplastia de recapeamento canina. Os produtos desenvolvidos nesse trabalho serão nomeados como \"fresa multilaminar sequencial\", \"máscara para furação centralizada\" e \"prótese e instrumentais cirúrgicos para cães\", para a artroplastia de recapeamento de quadril. Com os desenvolvimentos, é esperada uma redução no tempo da cirurgia, bem como um aumento na segurança, possibilitando maior sucesso nesses procedimentos em humanos, bem como trás nova tecnologia para a medicina veterinária. / Progressive technological innovations in the area of mechanical design, contribute to the adoption of new surgical procedures related to orthopedics. This work addresses the design development and manufacture of machining devices and surgical instruments to be used in resurfacing surgeries of the femoral head in humans and animals, seeking to improve this procedure in regards to a new technology related to bone structure for machining and drilling aligned with the femoral head. In this context, the relation time c accuracy was very well explored, in order to assist with efficiency surgeons and patients requiring surgery that reduces the interference on the skill of the surgeon on the surgery outcome. The simultaneous development of the multilaminar-mill, designed to machine the femoral head matching the internal geometry of the resurfacing prosthesis is an important tool for reducing the surgery time, as the tool changes during surgery as shown this thesis. The surgical instrument responsible for the proper operation of these machining devices is a customized guide drill mark capable of aligning the drill and the mill during drilling and milling of the femoral head, according to the angle of the femoral neck of each patient. This work deals with the design, development and manufacturing of a machining device prototype and surgical instruments to promote the centralized machining following the angle of the femur neck the reduction of surgery time and the innovate arthroplasty surgery in humans animals. The products developed in this work are named as \"sequential multilaminar mill\", \"drilling centering mask\" and \"prosthesis and instrumental for dogs\", for hip resurfacing arthroplasty. With the developments, it is expected to reduce the surgical time, as well increasing safety, allowing greater success in these procedures.

Cette thèse, née d’une collaboration entre le laboratoire LEMTA et l’entreprise Novastep, a pour but de concevoir une prothèse de resurfaçage des têtes métatarsiennes des rayons latéraux (2ème, 3ème et 4ème orteils). Ces rayons sont touchés par de nombreuses pathologies (arthrose, maladie de Freiberg, …) pouvant engendrer des douleurs et être handicapantes au quotidien. Bien que de nombreuses solutions prothétiques pour le resurfaçage des têtes métatarsiennes soient disponibles sur le marché, elles sont en majorité conçues pour le resurfaçage du 1ier rayon. La prothèse de Novastep est donc prévue pour offrir une solution viable pour le traitement de ces pathologies. Le développement de la prothèse passe par plusieurs étapes qui sont : • La recherche des exigences médicales et mécaniques à respecter ; • La conception de la prothèse ; • La mise au point de la technique opératoire (instrument pour la pose) ; • La réalisation des essais (vérification des performances de la prothèse). Ce cycle de conception permet de justifier les performances de la prothèse dans l’optique d’obtenir l’autorisation de mise sur le marché. En parallèle de la conception de la prothèse de resurfaçage, une étude de remodelage des métatarsiens après implantation a été effectuée. Cette étude a pour but, dans un premier temps, de présenter et valider un protocole pour la préparation des modèles EF de remodelage osseux à partir de données tomodensitométriques spécifiques au patient. Dans un deuxième temps, cette étude a permis d’analyser l’impact de la prothèse de Novastep sur l’os et de comparer ces résultats avec ceux obtenus pour une prothèse concurrente (LMHI de Wright Medical). Dans un dernier temps, l’influence de différents paramètres de la loi de remodelage et du modèle a été étudiée. A notre connaissance, ce travail est le premier portant sur le remodelage osseux d’un métatarsien prothésé. A terme, ce travail pourra aboutir à la création d’un outil d’aide à la décision destiné aux concepteurs pour les choix technologiques de design des prothèses et aux chirurgiens pour sélectionner la technique chirurgicale la plus adaptée à chaque patient. Pour ce faire, il sera nécessaire de valider les résultats issus des prévisions numériques de remodelage avec des résultats cliniques post-opératoires / This doctoral thesis, the result of a collaboration between LEMTA laboratory and Novastep company, explains the design of a metatarsal head resurfacing prosthesis of the lateral toes (2nd, 3rd and 4th toes). These toes can be affected by several pathologies, including arthritis and Freiberg’s disease, which are painful and can bec ripping in everyday life. Although many prosthetic solutions for the resurfacing of the metatarsal heads are available on the market, they are often developed for the first toe only. Novastep’s prosthesis was developed to afford a viable solution for the treatment of those pathologies in other toes as well. The development of this prosthesis requires several steps which are: • The definition of medical and mechanical requirements which must been taken into account ; • The design of the prosthesis ; • The development of the surgical technique, that is, the instrumentation for setting up the prosthesis ; • Mechanical and clinical testing to verify the performance of the prosthesis. This design cycle permits justification of the device’s performance necessary to obtain the market approval. In parallel with the resurfacing prosthesis, a study of metatarsal bone remodeling after implantation was realized. This study aimed to present and validate a protocol for the preparation of finite element models of bone remodeling from patient specific computed-tomography data. It also permitted analysis of the impact of the Novastep’s prosthesis on the metatarsal and comparison of those resuts with results obtained with a competitor’s equivalent prosthesis (LMHI of Wright Medical). To our knowledge, this study was the first on the bone remodeling of a prosthetic metatarsal. In the long term, this work could lead to the creation of a decision-making tool for designers for the technological choices of prosthesis design

Today is the surface hip repacement very often surgery becouse of new studies and improvements. For young and active people it's the best way to delay implantation of a total hip replacement. The objective of this study was to perform finite-element analyses of computational model of the partial/total surface replacement, conventional partial/total replacement and physiological hip joint. We obtained strain-stress states from these analyses. All results were compared one another and then were confronted with results of the physiological hip joint. The three-dimensional computational model consists of these components: sacral, pelvic and femoral bone, muscles, artificial socket, and surface hip replacement. We were using FEM system ANSYS. The geometrical models of bones were generated by means of computed tomography (CT) images. The FE model of bone reflects two types of the bone tissues (trabecular and cortical bone) and muscles which are important when standing on one leg. The model of the muscle corresponds to isometric contraction. The implants material and bone tissues were modelled as isotropic linear elastic material. The model was loaded by force, corresponding to load by standing on one leg.

The Melanocyte Keratinocyte Transplantation Procedure (MKTP) is an effective surgical replacement of lost melanocytes in recalcitrant vitiligo and pigmentary skin disorders. However, it is only effective in stable vitiligo lesions because active autoimmunity destroys the newly transplanted melanocytes. Despite careful selection of candidates based on the reported clinical stability, the success of the procedure is still unpredictable. MKTP candidates with non-segmental, segmental, and mixed vitiligo, as well as hypopigmented scars and Piebaldism patients were enrolled to our studies. Our aim was first, to investigate the possible immunological mechanisms responsible for the unpredictable post- transplantation outcomes, including T cell subsets and inflammatory chemokines, by correlating these biomarkers with clinical phenotypes, duration of stability, and surgical outcomes. We used suction blister biopsy, a minimally invasive technique that we developed to sample human skin. Moreover, we quantified transplanted melanocytes in the suspension using flow cytometry. Following MKTP, we corelated these biomarkers to the repigmentation score. We found that CD8+ T cells remain in some clinically stable vitiligo lesions, correlate negatively with the post-surgical score of repigmentation, and inversely impact the durability of the responses. Interestingly, the number of transplanted melanocytes in the suspension and the duration of stability do not have prognostic roles. Based on our findings and in a second group of patients, we suppressed the activity of T cells to enhance the outcomes of MKTP. We used Ruxolitinib, JAK1/2 inhibitor, in a triple blinded randomized controlled within subject study, in comparison with Tacrolimus (a calcineurin inhibitor and the standard of care treatment in vitiligo) as well as placebo control. We found lower T cell infiltrate, lower chemokines, and better skin repigmentation in lesions treated with MKTP plus Ruxolitinib or Tacrolimus than in lesions treated with MKTP plus placebo. Lastly, we compared two different types of laser in preparation of the recipient skin for MKTP - ablative versus fractional Er:YAG laser. We found that the ablative laser is combined with minimal CD8+ T cell epidermal infiltrate and superior repigmentation score in comparison to more infiltrate and lower repigmentation score with the fractional laser. Taken together, these results from our studies provide novel insight to predict the optimal surgical candidates and will improve surgical outcomes. It advances the treatment of vitiligo by uncovering the impact of autoimmunity on the success of repigmentation and discovering new approaches to optimize the surgical treatment options in patients with vitiligo and pigmentary skin disorders.

É estudada, conceitualmente a técnica de recapeamento de quadril de cães como modelo cirúrgico. A artroplastia do quadril foi desenvolvida com a finalidade de estabelecer a mobilidade articular e também no alívio da dor de pacientes humanos. Em animais, principalmente os cães, a artroplastia total, é um procedimento cirúrgico muito utilizado na articulação coxofemoral para a correção de patologias de quadril, sejam elas degenerativas traumáticas ou inflamatórias além de aliviar a dor. A artroplastia de recapeamento de quadril em humanos tem se mostrado uma técnica muito eficiente por estar próxima da anatomia natural do quadril e tem sido aplicada em pacientes jovens e ativos. A vantagem de se realizar a técnica de recapeamento é que nesta, há uma ressecção mínima da cabeça femoral e que promove uma melhora em relação à estabilidade da articulação, entretanto essa técnica ainda não é aplicada em animais. O presente trabalho tem por objetivo estudar a técnica de recapeamento de quadril de cães de forma análoga as técnicas aplicadas em humanos e também, propor um projeto de ferramental cirúrgico específico em conjunto com o protocolo cirúrgico. A técnica conceitual de artroplastia de recapeamento de quadril de cães foi desenvolvida a partir de um fêmur canino onde foram desenvolvidos os conceitos da técnica cirúrgica e o protótipo do ferramental cirúrgico necessário para o desenvolvimento desta técnica. Inicialmente foram feitas aquisições das imagens dos objetos do trabalho (fêmur canino, ferramental cirúrgico e prótese cirúrgica) que foram convertidas em arquivos CAD; a partir destes foram gerados cópias em gesso através do processo de impressão 3D do ferramental cirúrgico desde o guia de furação até a fresa de chanframento e também da prótese cirúrgica de recapeamento. A fabricação do ferramental cirúrgico obtido pelo processo de impressão 3D possibilitou uma análise visual dos protótipos que serviram de modelos para a fabricação do ferramental cirúrgico definitivo, sendo este, confeccionado em aço. Isso permitiu sua validação em bancada de laboratório através de testes realizados em modelos de ossos de cães em resina. Conclui-se que a técnica de recapeamento de quadril de cães validada em bancada de laboratório poderá ser realizada em conjunto com o ferramental cirúrgico proposto para em um futuro muito próximo ser usado em articulações de cães portadores de displasia coxofemoral devido a sua funcionalidade e à demanda de casos clínicos para este procedimento. A técnica cirúrgica de recapeamento estudada poderá ser oferecida a população a um custo acessível por ser inovadora e promissora no contexto da ortopedia veterinária. / The study conceptually describes a surgical model for dog hip resurfacing technique. Hip arthroplasty was developed to restore joint mobility and relieve of human patients pain. In animals, especially dogs, total arthroplasty is a surgical procedure commonly used to correct traumatic, degenerative and inflammatory hip diseases and alleviate pain. The resurfacing hip arthroplasty in humans, applied in young and active patients, has shown to be an efficient technique. The advantage of using this technique is that there will be a minimal resection of the femoral head, improving the stability of the joint; however it has not been applied to animals yet. The present dissertation reports on the study of hip resurfacing technique for dogs in a similar way it is applied in humans. It also proposes a specific surgical tooling design in conjunction with the surgical protocol. The technical concept of hip resurfacing arthroplasty for dogs was developed from a canine femur from which the concepts of the surgical technique and the prototypes of the necessary surgical tools were developed. Initially, images of the objects used in the work (canine femur, surgical tools and surgical prosthesis) were acquired. They were then converted into CAD files, which generated plaster copies of surgical tools, from the hole guide to the to cutter and chamfer, and also surgical resurfacing prosthesis through the 3D printing process. The manufacture of the surgical tools models obtained by 3D printing process allowed a visual analysis of the prototypes that served as references for the definitive surgical tool made in steel. Such tools were validated by means of laboratory bench tests using resin models of dogs\' bones. It was possible to conclude that the technique of hip resurfacing in dogs can be employed in conjunction with the proposed surgical tools in the joints of dogs with hip dysplasia in a very near future. Due to its full functionality and large demand of clinical cases for this procedure, the technique may be offered to the population at an affordable cost. It is also an innovative and promising technique in the context of veterinary orthopedics.

É estudada, conceitualmente a técnica de recapeamento de quadril de cães como modelo cirúrgico. A artroplastia do quadril foi desenvolvida com a finalidade de estabelecer a mobilidade articular e também no alívio da dor de pacientes humanos. Em animais, principalmente os cães, a artroplastia total, é um procedimento cirúrgico muito utilizado na articulação coxofemoral para a correção de patologias de quadril, sejam elas degenerativas traumáticas ou inflamatórias além de aliviar a dor. A artroplastia de recapeamento de quadril em humanos tem se mostrado uma técnica muito eficiente por estar próxima da anatomia natural do quadril e tem sido aplicada em pacientes jovens e ativos. A vantagem de se realizar a técnica de recapeamento é que nesta, há uma ressecção mínima da cabeça femoral e que promove uma melhora em relação à estabilidade da articulação, entretanto essa técnica ainda não é aplicada em animais. O presente trabalho tem por objetivo estudar a técnica de recapeamento de quadril de cães de forma análoga as técnicas aplicadas em humanos e também, propor um projeto de ferramental cirúrgico específico em conjunto com o protocolo cirúrgico. A técnica conceitual de artroplastia de recapeamento de quadril de cães foi desenvolvida a partir de um fêmur canino onde foram desenvolvidos os conceitos da técnica cirúrgica e o protótipo do ferramental cirúrgico necessário para o desenvolvimento desta técnica. Inicialmente foram feitas aquisições das imagens dos objetos do trabalho (fêmur canino, ferramental cirúrgico e prótese cirúrgica) que foram convertidas em arquivos CAD; a partir destes foram gerados cópias em gesso através do processo de impressão 3D do ferramental cirúrgico desde o guia de furação até a fresa de chanframento e também da prótese cirúrgica de recapeamento. A fabricação do ferramental cirúrgico obtido pelo processo de impressão 3D possibilitou uma análise visual dos protótipos que serviram de modelos para a fabricação do ferramental cirúrgico definitivo, sendo este, confeccionado em aço. Isso permitiu sua validação em bancada de laboratório através de testes realizados em modelos de ossos de cães em resina. Conclui-se que a técnica de recapeamento de quadril de cães validada em bancada de laboratório poderá ser realizada em conjunto com o ferramental cirúrgico proposto para em um futuro muito próximo ser usado em articulações de cães portadores de displasia coxofemoral devido a sua funcionalidade e à demanda de casos clínicos para este procedimento. A técnica cirúrgica de recapeamento estudada poderá ser oferecida a população a um custo acessível por ser inovadora e promissora no contexto da ortopedia veterinária. / The study conceptually describes a surgical model for dog hip resurfacing technique. Hip arthroplasty was developed to restore joint mobility and relieve of human patients pain. In animals, especially dogs, total arthroplasty is a surgical procedure commonly used to correct traumatic, degenerative and inflammatory hip diseases and alleviate pain. The resurfacing hip arthroplasty in humans, applied in young and active patients, has shown to be an efficient technique. The advantage of using this technique is that there will be a minimal resection of the femoral head, improving the stability of the joint; however it has not been applied to animals yet. The present dissertation reports on the study of hip resurfacing technique for dogs in a similar way it is applied in humans. It also proposes a specific surgical tooling design in conjunction with the surgical protocol. The technical concept of hip resurfacing arthroplasty for dogs was developed from a canine femur from which the concepts of the surgical technique and the prototypes of the necessary surgical tools were developed. Initially, images of the objects used in the work (canine femur, surgical tools and surgical prosthesis) were acquired. They were then converted into CAD files, which generated plaster copies of surgical tools, from the hole guide to the to cutter and chamfer, and also surgical resurfacing prosthesis through the 3D printing process. The manufacture of the surgical tools models obtained by 3D printing process allowed a visual analysis of the prototypes that served as references for the definitive surgical tool made in steel. Such tools were validated by means of laboratory bench tests using resin models of dogs\' bones. It was possible to conclude that the technique of hip resurfacing in dogs can be employed in conjunction with the proposed surgical tools in the joints of dogs with hip dysplasia in a very near future. Due to its full functionality and large demand of clinical cases for this procedure, the technique may be offered to the population at an affordable cost. It is also an innovative and promising technique in the context of veterinary orthopedics.

Hip resurfacing arthroplasty has changed the treatment of end stage arthritis without severe deformity for young, active adults. Presently, there are varying clinical approaches to implant design selection and cementation techniques. The purpose of this project is to determine what amount of reamer-femoral component offset allows for the best cement penetration into the femoral head. Rapid prototyped femoral component models were produced with reamer femoral component offsets of 0.0 mm, 0.5 mm, and 1.0 mm. After implantation onto models of reamed femoral heads made from high-density open-cell reticulated carbon foam, cement penetration was assessed from cross-sections of the foam-implant unit. Increased offset was found to decrease the extent of cement over penetration from the dome and chamfer. Increased offset also yielded optimal cement penetration as measured from the walls. Finally, increased offset was found to increase the height of cement mantle formation while maintaining complete seating of all implants.

Hip resurfacing is an alternative to total hip arthroplasty for the young and active patient likely to outlive traditional means of hip joint replacement. The acetabular cup is implanted in much the same fashion as an uncemented total hip arthroplasty, however, implantation of the femoral component is unique to hip resurfacing, presenting both distinct benefits and limitations. Hip resurfacing spares much of the proximal femur including the femoral neck and portions of the femoral head. This may be advantageous if the patient requires revision surgery; however, preservation of the femoral neck bears with it the risk of femoral neck fracture. The exact mechanism of neck fracture is not fully understood. Avoiding potential fracture risks is vital to ensuring optimal patient outcomes. The current work investigated mechanical femoral head preparatory factors that may predispose to femoral neck fracture. Intra-operative computer navigation is emerging as the gold-standard in orthopaedic care. In hip resurfacing, navigation may improve the surgeon’s ability to optimally implant the resurfacing prosthesis; however, much of this technology is still in its infancy and requires investigation into the accuracy and repeatability of this peri-operative tool. Pre-operative planning can assist the surgeon in optimally determining the size and position of the resurfacing components, specifically in reference to the patient’s unique anatomy, prior to performing the operation. This may aid in correct implant selection and provide a basis on which to conduct intra-operative navigation. However, the accuracy and repeatability of pre-operative planning for hip resurfacing has not yet been established. Thus, this body of work looked to establish a clear methodology for pre-operative planning, intra-operative computer navigation and surgical technique in order to optimize preparation of the femoral head, ultimately reducing the risk of femoral neck fracture in hip resurfacing.

Hip resurfacing is an alternative to total hip arthroplasty for the young and active patient likely to outlive traditional means of hip joint replacement. The acetabular cup is implanted in much the same fashion as an uncemented total hip arthroplasty, however, implantation of the femoral component is unique to hip resurfacing, presenting both distinct benefits and limitations. Hip resurfacing spares much of the proximal femur including the femoral neck and portions of the femoral head. This may be advantageous if the patient requires revision surgery; however, preservation of the femoral neck bears with it the risk of femoral neck fracture. The exact mechanism of neck fracture is not fully understood. Avoiding potential fracture risks is vital to ensuring optimal patient outcomes. The current work investigated mechanical femoral head preparatory factors that may predispose to femoral neck fracture. Intra-operative computer navigation is emerging as the gold-standard in orthopaedic care. In hip resurfacing, navigation may improve the surgeon’s ability to optimally implant the resurfacing prosthesis; however, much of this technology is still in its infancy and requires investigation into the accuracy and repeatability of this peri-operative tool. Pre-operative planning can assist the surgeon in optimally determining the size and position of the resurfacing components, specifically in reference to the patient’s unique anatomy, prior to performing the operation. This may aid in correct implant selection and provide a basis on which to conduct intra-operative navigation. However, the accuracy and repeatability of pre-operative planning for hip resurfacing has not yet been established. Thus, this body of work looked to establish a clear methodology for pre-operative planning, intra-operative computer navigation and surgical technique in order to optimize preparation of the femoral head, ultimately reducing the risk of femoral neck fracture in hip resurfacing.