A artroplastia é, em última análise, a opção final para o tratamento da osteoartrose. Com o aumento do número de indicações deste procedimento, a troca (artroplastia total de quadril de revisão – ATQR) dos componentes também passou a ser mais frequente. Os defeitos ósseos ou falhas ósseas são problemas que podem ser encontrados quando se realiza uma ATQR e, eles devem ser reparados, ou seja, o quadril do paciente a receber outra prótese necessita ser reconstruído. Para isto a grande maioria das técnicas empregadas requer o uso de enxerto ósseo e, devido a este motivo este tecido tem se tornado um dos tecidos mais transplantados na atualidade. Porém a demanda para utilização dos enxertos, na maioria provenientes de bancos de tecidos ósseos, tem aumentado, mas o suprimento é insuficiente. Portanto faz-se necessário a busca por novas tecnologias e alternativas aos bancos de tecidos. O enxerto bovino liofilizado (EBL) é uma destas opções, sua produção em livre demanda suas características físicas e químicas semelhantes ao osso humano e sua boa repercussão clínico-radiológica o torna uma alternativa viável. Este estudo tem o objetivo de verificar e quantificar a neoformação óssea com o uso do EBL pelo uso da avaliação histológica. Realizou-se um estudo de casos de Julho de 2000 a Abril de 2013 no Hospital de Clínicas de Porto Alegre (HCPA), onde se incluíram sujeitos que foram submetidos a uma cirurgia prévia cirurgia de ATQR onde foi utilizado o EBL os quais internaram posteriormente para uma segunda cirurgia de ATQR não relacionada a falha do enxerto e sim a falha da prótese. Nesta segunda cirurgia realizou-se a biópsia óssea. Quatorze sujeitos foram analisados, sendo 64,3% do sexo feminino. A média de idade dos pacientes foi 52,36±18,55. Neoformação óssea estava presente em 85,7% dos sujeitos, e constituiu 61,79% da área total de matriz óssea. O diagnóstico de absorção do EBL estava presente em 12 sujeitos. Uma forte correlação de proporção inversa foi constatada pelo teste de Pearson entre a porcentagem de osso neoformado e a porcentagem de EBL na área total de matriz óssea (p=0,001). Nenhuma resposta inflamatória foi encontrada. Concluiu-se que houve neoformação óssea adequada na grande maioria dos casos sendo o EBL uma boa estrutura osteocondutora, podendo ser considerado uma alternativa aos outros enxertos ósseos no tratamento das falhas ósseas. / Arthroplasty is, ultimately, the final option for the treatment of osteoarthritis. With the increasing number of indications of this procedure, the exchange (total hip arthroplasty revision surgery- THARS) also became more frequent. The bone defects are problems that can be encountered when conducting a THARS and this defect must be repaired, in other words, the patient's hip needs to be rebuilt before receive a new prosthesis. Most of techniques used to rebuild requires the use of bone graft, and because of this reason, this tissue has become one of the most transplanted tissues today. However the demand for the use of grafts, mostly from bone tissue banks, has increased, but the supply is insufficient. Therefore it is necessary to search for new technologies and alternatives to tissue banks. The bovine lyophilized xenograft (BLX) is one of these options; the production on free demand, its physical and chemical characteristics similar to human bone and its good clinical and radiological outcomes makes it a viable alternative. The aim of this study was to verify and quantify new bone formation by the histological analysis in subjects who received the BLX. This was a case series from July 2000 to April 2013 realized in the Hospital de Clínicas de Porto Alegre. This study included patients who underwent to a THARS where was used the BLX, which later was admitted to a second THARS surgery, not related to the xenograft failure but a mechanical failure of the implant. In this second surgery was performed the bone biopsy. Fourteen subjects were analyzed, 64.3% were female. The average age of patients was 52.36 ± 18.55 years. New bone formation was present in 85.7% of subjects, and constituted 61.79% of the total bone matrix. The diagnosis of BLX absorption was present in 12 subjects. A strong inverse correlation founded by the Pearson's test was observed between the proportion of new bone and the proportion of BLX (p=0.001). No inflammatory response was found. Was concluded that there was suitable bone formation in the vast majority of the cases, as well as the BLX is a good osteoconductive scaffold and can be considered an alternative to other bone graft in the treatment of bone defects.

A vibroacustografia (VA) é uma técnica de imagem de alta resolução lateral (<0,7 mm), livre de speckles, não invasiva e que utiliza radiação não-ionizante, baseada no fenômeno de combinação não-linear de ondas de ultrassom (MHz) que gera uma região focal estreita de baixa frequência (kHz). Neste trabalho, propõe-se uma avaliação tridimensional baseada em imagens de VA da área descoberta de implantes, após o procedimento cirúrgico de artroplastia total de quadril (ATQ). A ATQ é uma técnica terapêutica de substituição de articulações do quadril por implantes, em pacientes com osteoartrose avançada. Atualmente, o acompanhamento pós-operatório é auxiliado pela análise de radiografia plana por raios-X. Contudo, esta técnica apresenta limitações na avaliação da estabilidade dos implantes, tais como: avaliação imprecisa da área, uma vez que, a radiografia plana trata o problema tridimensional como bidimensional; impossibilidade de visualização de algumas regiões do implante, devido ao sobreposicionamento das regiões numa imagem planar; restrição do uso de radiação ionizante na região da pelve em pacientes jovens. Devido à alta atenuação da onda de ultrassom incidindo sobre objetos densos, a VA pode ser ajustada para adquirir imagens relativas, principalmente, à superfície destes. Uma correção da topologia baseada na geometria do implante é apresentada, a fim de se avaliar com precisão a área superficial na representação tridimensional da imagem de VA. A correção da topologia baseada em aquisições em modo-B também é apresentada, sendo útil na avaliação da forma de ossos ou nos casos em que a forma do objeto estudado é desconhecida. Além disso, é apresentado um estudo numérico da utilização de transdutores matriciais reconfiguráveis (RCA, do inglês reconfigurable array) para a formação de feixe em VA. Um estudo paramétrico da seleção de abertura, número de canais, número de elementos, distância focal e parâmetros de varredura eletrônica do feixe é apresentado para demonstrar a viabilidade e avaliar o desempenho da imagem de VA utilizando o RCA. A função de espalhamento de ponto do sistema foi calculada com base em métodos de espectro angular usando a aproximação de Fresnel para fontes retangulares. Foram discutidas as vantagens de transdutores bidimensionais e RCA, e aspectos relacionados à importância clínica da implementação do RCA na VA, tais como resolução espacial, taxa de aquisição da imagem e implementação do RCA em máquinas comerciais. Conclui-se que: a aquisição de imagens por VA foi menos sensível ao ângulo de incidência das ondas de ultrassom do que por modo-B e apresentou alta resolução e alto contraste entre o osso e o implante, o que permitiu uma avaliação precisa da área exposta do implante; os transdutores RCA podem aprimorar a aquisição de imagens por VA, devido à sua resolução espacial similar à de transdutores confocais e à possibilidade de deflexão eletrônica do feixe (em inglês steering) nos planos de elevação e azimutal. / Vibro-acoustography (VA) is a high lateral resolution (<0.7 mm), speckle-free, non- ionizing and non-invasive image based on the nonlinear combination phenomenon of ultrasound waves (MHz) that generates a narrow focus region of low frequency (kHz). In this work, we propose a VA-based tridimensional evaluation of the exposed area of implants, after total hip arthroplasty (THA). THA is a therapeutic surgery procedure in which the hip joints are replaced by metal prostheses in patients with advanced osteoarthritis. Currently, the postoperative assessment of THA is performed by analyzing planar X-ray radiographies. However, this technique presents limitations in the implant stability evaluation such as: inaccurate evaluation of the area, since the planar radiography reduces the tridimensional problem into a two-dimensional one; problems in the visualization of some regions of the implants due to the superimposition of the regions; limitations of using ionizing radiation in the pelvis region of young patients. Due to the high attenuation of the ultrasound wave into objects of high density, the VA image can be set to mainly acquire the surface information. Topological correction based on the geometry of the implant is presented in order to accurately evaluate the surface area in tridimensional representation of the VA image. The topological correction based on B-mode slices is also presented and is useful in the evaluation of bone shape or in cases which the shape of the object is unknown. Furthermore, it is presented a numerical study of the use of reconfigurable arrays (RCA) for VA beam formation. A parametric study of the aperture selection, number of channels, number of elements, focal distance and steering parameters is presented in order to show the feasibility and evaluate the performance of VA imaging based on RCA. The point-spread function of the system is calculated based on angular spectrum methods using the Fresnel approximation for rectangular sources. Advantages of two-dimensional and RCA arrays and aspects related to clinical importance of the RCA implementation in VA such as spatial resolution, image frame-rate, and commercial machine implementation are discussed. It is concluded that: the VA image is less sensitive to the wave incident angle than B-mode; the VA image presents high-resolution and high-contrast between bone and implant, which allowed an accurate evaluation of the uncovered area; RCA transducers improve the VA acquisition by producing spatial resolution similar to confocal transducers, and due to the possibility of steering in elevation and azimuthal planes.

O presente estudo é uma coorte contemporânea de 49 pacientes (51 quadris) submetidos à reconstrução acetabular com enxerto ósseo liofilizado humano ou bovino, picado e impactado, associado a reforço acetabular. Foi realizado no Serviço de Ortopedia e Traumatologia do Hospital de Clínicas de Porto Alegre (HCPA), no período de maio de 1997 a fevereiro de 2005. Os pacientes foram divididos em dois grupos: o grupo 1 (n=26) foi composto pelos que receberam enxerto ósseo liofilizado de origem humana e o grupo 2 (n=25), por aqueles que receberam enxerto de origem bovina. O reforço utilizado em todos os casos foi da MDT® (SP-Brasil). O tempo médio de seguimento foi de 55 e 49 meses respectivamente. Os enxertos ósseos purificados e liofilizados foram produzidos pelo Banco de Tecidos do HCPA. A análise clínica baseou-se no escore de Merle d’Aubigné e Postel e a radiográfica, nos critérios de Conn et al.para osteointegração dos enxertos que avalia a radiolucência, a densidade, a formação de trabeculado ósseo e a migração do componente. Não foram encontradas diferenças clínicas ou radiográficas relevantes entre os grupos, obtendo-se em torno de 88,5 e 76% de integração do enxerto. Estes resultados são comparáveis aos relatados na literatura com o uso de enxerto alógeno congelado e estimulam a continuidade da pesquisa sobre enxertos liofilizados de origem humana e bovina. / Background: this is a cohort trial of 49 patients (51 hips) submitted to revision acetabular component of total hip arthroplasty, using impacted human and bovine freeze-dried cancellous bone grafts and reinforcement device. The study was carried out in the Hospital de Clínicas de Porto Alegre (HCPA) from May 1997 to February 2005. The aim of the study was to compare clinical and radiographic graft incorporation capability between human and bovine freeze-dried bone grafts. Patients and Methods: the patients were divided in two groups: Group 1 (n=26) was composed by those receiving human grafts, and Group 2 (n=25), bovine grafts. The follow-up average was 55 and 49 months. The grafts were purified and freeze-dried at the Tissue Bank of the HCPA.The clinical analysis was based on the score of Merle d’Aubigné and Postel; and the radiographic analysis in an established score based in Conn’s et al. criteria for radiographic bone incorporation. Results: no clinical or radiographic differences were observed between the groups and both groups showed an overall rate of 88.5 and 76% of graft integration. Conclusion: these results are comparable to those reported in the literature with the use of deep-frozen grafts. Therefore, bovine and human freeze-dried grafts can be safely and adequately used in acetabular revision in total hip arthroplasty.

A artroplastia é, em última análise, a opção final para o tratamento da osteoartrose. Com o aumento do número de indicações deste procedimento, a troca (artroplastia total de quadril de revisão – ATQR) dos componentes também passou a ser mais frequente. Os defeitos ósseos ou falhas ósseas são problemas que podem ser encontrados quando se realiza uma ATQR e, eles devem ser reparados, ou seja, o quadril do paciente a receber outra prótese necessita ser reconstruído. Para isto a grande maioria das técnicas empregadas requer o uso de enxerto ósseo e, devido a este motivo este tecido tem se tornado um dos tecidos mais transplantados na atualidade. Porém a demanda para utilização dos enxertos, na maioria provenientes de bancos de tecidos ósseos, tem aumentado, mas o suprimento é insuficiente. Portanto faz-se necessário a busca por novas tecnologias e alternativas aos bancos de tecidos. O enxerto bovino liofilizado (EBL) é uma destas opções, sua produção em livre demanda suas características físicas e químicas semelhantes ao osso humano e sua boa repercussão clínico-radiológica o torna uma alternativa viável. Este estudo tem o objetivo de verificar e quantificar a neoformação óssea com o uso do EBL pelo uso da avaliação histológica. Realizou-se um estudo de casos de Julho de 2000 a Abril de 2013 no Hospital de Clínicas de Porto Alegre (HCPA), onde se incluíram sujeitos que foram submetidos a uma cirurgia prévia cirurgia de ATQR onde foi utilizado o EBL os quais internaram posteriormente para uma segunda cirurgia de ATQR não relacionada a falha do enxerto e sim a falha da prótese. Nesta segunda cirurgia realizou-se a biópsia óssea. Quatorze sujeitos foram analisados, sendo 64,3% do sexo feminino. A média de idade dos pacientes foi 52,36±18,55. Neoformação óssea estava presente em 85,7% dos sujeitos, e constituiu 61,79% da área total de matriz óssea. O diagnóstico de absorção do EBL estava presente em 12 sujeitos. Uma forte correlação de proporção inversa foi constatada pelo teste de Pearson entre a porcentagem de osso neoformado e a porcentagem de EBL na área total de matriz óssea (p=0,001). Nenhuma resposta inflamatória foi encontrada. Concluiu-se que houve neoformação óssea adequada na grande maioria dos casos sendo o EBL uma boa estrutura osteocondutora, podendo ser considerado uma alternativa aos outros enxertos ósseos no tratamento das falhas ósseas. / Arthroplasty is, ultimately, the final option for the treatment of osteoarthritis. With the increasing number of indications of this procedure, the exchange (total hip arthroplasty revision surgery- THARS) also became more frequent. The bone defects are problems that can be encountered when conducting a THARS and this defect must be repaired, in other words, the patient's hip needs to be rebuilt before receive a new prosthesis. Most of techniques used to rebuild requires the use of bone graft, and because of this reason, this tissue has become one of the most transplanted tissues today. However the demand for the use of grafts, mostly from bone tissue banks, has increased, but the supply is insufficient. Therefore it is necessary to search for new technologies and alternatives to tissue banks. The bovine lyophilized xenograft (BLX) is one of these options; the production on free demand, its physical and chemical characteristics similar to human bone and its good clinical and radiological outcomes makes it a viable alternative. The aim of this study was to verify and quantify new bone formation by the histological analysis in subjects who received the BLX. This was a case series from July 2000 to April 2013 realized in the Hospital de Clínicas de Porto Alegre. This study included patients who underwent to a THARS where was used the BLX, which later was admitted to a second THARS surgery, not related to the xenograft failure but a mechanical failure of the implant. In this second surgery was performed the bone biopsy. Fourteen subjects were analyzed, 64.3% were female. The average age of patients was 52.36 ± 18.55 years. New bone formation was present in 85.7% of subjects, and constituted 61.79% of the total bone matrix. The diagnosis of BLX absorption was present in 12 subjects. A strong inverse correlation founded by the Pearson's test was observed between the proportion of new bone and the proportion of BLX (p=0.001). No inflammatory response was found. Was concluded that there was suitable bone formation in the vast majority of the cases, as well as the BLX is a good osteoconductive scaffold and can be considered an alternative to other bone graft in the treatment of bone defects.

Le but du travail réalisé dans cette thèse était d’approfondir les connaissances en matière d’utilisation du couple de frottement céramique-céramique dans l’implantologie moderne de hanche sans ciment. L’étude clinique de 100 prothèses totales de hanche sans ciment avec un recul de 9 ans a permis de montrer la fiabilité du couple de frottement céramique en terme d’usure, de biocompatibilité et d’ostéointégration. Par la suite, la comparaison de la méthode d’implantation de ces implants (impaction du métal-back avec ou sans adjonction de vis supplémentaires) a montré que la rigidité de la céramique n’était pas incompatible avec une impaction simple du métal-back, pour des patients qui ne présentent pas de fragilité osseuse. Nous avons ensuite étudié plus particulièrement une complication de la céramique, le grincement ou squeaking. Une étude in vitro du phénomène, a permis de reproduire ce phénomène dans des conditions de lubrification optimale, avec la présence d’un troisième corps métallique entre les surfaces de frottement, suggérant l’importance des problèmes de lubrification dans la genèse du phénomène. L’analyse d’explant a conforté notre hypothèse, mettant en évidence l’importance du dessin des implants afin d’éviter les conflits prothétiques pouvant générer des particules métalliques. Enfin, l’analyse sur le long terme du phénomène de squeaking a montré son faible impact sur la survie des implants et sur la qualité de vie des patients. Ce travail, qui a associé des analyses cliniques et biomécaniques nous conforte dans l’utilisation de la céramique comme couple de frottement dans les prothèses totales de hanche sans ciment, insiste sur l’importance du dessin et du positionnement des implants pour éviter les complications qui peuvent survenir et permet de mieux connaître le problème du squeaking et ses conséquences / The aim of the study done in this thesis was to enhance the knowledge in the use of ceramic on ceramic bearing for cementless total hip arthroplasty. A clinical study of 100 cementless total hip arthroplasty at 9 years of follow-up showed the reliability of ceramic in terms of wear, biocompatibility and osseointegration. Subsequently, the comparison of the method for implantation of the implants (press-fit with or without additional screws fixations) showed that the stiffness of ceramic was not inconsistent with a simple impaction, for patients who do not present bone fragility. We then studied a particular complication of ceramic bearing, the squeaking noise. An in vitro study of this phenomenon, allowed us to reproduce squeaking in lubricated conditions, with the presence of a third metal body between the frictions surfaces, suggesting the importance on lubrication damages in the genesis of this phenomenon. Analysis of explants has confirmed our hypothesis, highlighting the importance of implant design, to avoid impingement, potentially generating metal particles. Finally, the long-term analysis of squeaking phenomenon showed its low impact on implant survival and patient’s quality of life. This work, which involved clinical and biomechanical analysis, confirms the interest for the use of ceramics bearings in total hip arthroplasty, emphasizes the importance of implant design and implant positioning, to avoid complications, and helps for a better understanding with the problem of squeaking and its consequences

The diploma thesis is focused on the run-in phase of total hip replacement. Mutual adjustment of contact surfaces takes place in this phase and polyethylene acetabular cup shows notable creep behaviour. The magnitude of creep deformations is assessed experimentally in relation to acetabular cups orientation in human body after its implantation. The condition of articulating surfaces is also assessed as well as resulting coefficient of friction in run-in phase. Physiological load and kinematics of the artificial joint as well as physiological conditioning is achieved by new module of existing joint simulator, which is created as part of this thesis. Deformations and condition of articulating surfaces are assessed via optical methods and SEM. Findings about the run-in phase are compared with existing FEM analyses to evaluate simplifications used in these analyses. Measurement of creep deformations has also potential to improve the accuracy of acetabular wear diagnosis in clinical practice.

Background: Guidelines recommend the use of multiple pharmacologic agents and/or mechanical compressive devices for prevention of venous thromboembolism, but preference for any specific agent is no longer given in regard to safety or efficacy. Objective: To compare postoperative bleeding rates in patients receiving enoxaparin, rivaroxaban, or aspirin for thromboprophylaxis after undergoing elective total hip arthroplasty or total knee arthroplasty. Methods: This retrospective cohort analysis evaluated patients who received thromboprophylaxis with either enoxaparin, rivaroxaban, or aspirin. All data were collected from the electronic medical record. The primary outcome was any postoperative bleeding. Results: A total of 1244 patients were included with 366 in the aspirin, 438 in the enoxaparin, and 440 in the rivaroxaban arms. Those who received aspirin or enoxaparin were less likely to experience any bleeding compared to those patients who received rivaroxaban (P <.05). There was also a lower rate of major bleeding in these groups, but the differences were not significant. Conclusions: Aspirin and enoxaparin conferred similar bleeding risks, and both exhibited less bleeding than patients who received rivaroxaban.

Background: The Regulation of Coagulation in Orthopedic Surgery to Prevent Deep Venous Thrombosis and Pulmonary Embolism (RECORD) 1 to 4 trials compared rivaroxaban 10 mg daily with commonly used doses of enoxaparin and demonstrated similar rates of VTE and bleeding. Objective: To evaluate bleeding events between patients who received enoxaparin or rivaroxaban for prevention of venous thromboembolism (VTE) following total hip arthroplasty (THA) or total knee arthroplasty (TKA). Methods: Retrospective cohort that compared patients undergoing THA and TKA who received enoxaparin (enoxaparin) with those who received rivaroxaban (rivaroxaban) and also with those who received enoxaparin in the RECORD 1 to 4 trials (enoxaparin RECORD). The primary outcome was any postoperative bleeding, defined as a composite of major and clinically relevant nonmajor bleeding based on the definitions in the RECORD 1 to 4 trials. Results: There was a lower rate of any postoperative bleeding (2.2% vs 6.8%, P = 0.004) in patients who received enoxaparin compared with rivaroxaban, and bleeding rates between the enoxaparin group and the enoxaparin RECORD groups were similar (2.2% vs 2.5%, P = 0.085). Major bleeding in the enoxaparin group (0.2%) was not significantly different from that in the rivaroxaban group (1.4%, P = 0.12) or the RECORD group (0.2%, P = 0.93). Clinically relevant nonmajor bleeding was also lower in the enoxaparin group compared with the rivaroxaban group (2.0% vs 5.5%, P = 0.012). Conclusions: The use of enoxaparin for VTE prophylaxis following THA and TKA was associated with a lower rate of the primary outcome (any postoperative bleeding) compared with the use of rivaroxaban in a similar cohort of patients.

Bakgrund: Total höftplastik är en operation där en protes ersätter höftleden. Ingreppet genomförs alltmer i dagkirurgi. Rehabiliteringen sker i hemmet med uppföljningsbesök av fysioterapeut. Följsamhet till rehabilitering är viktigt för att återfå funktion. Insikt i patienters upplevelser av rehabilitering kan ge ny värdefull kunskap för fysioterapi med beteendemedicinsk inriktning. Syfte: Syftet med studien är att studera hur patienter som genomgått total höftplastik i dagkirurgi upplever följsamhet till postoperativ rehabilitering. Metod: Deskriptiv kvalitativ design med induktiv ansats. Sex patienter som genomgått total höftplastik i dagkirurgi inkluderades och deltog i individuella semistrukturerade intervjuer. En kvalitativ innehållsanalys tillämpades för att analysera data från intervjuerna. Resultat: Analysen resulterade i 15 underkategorier med följande fem huvudkategorier: Vikten av en bra start, Betydelsen av socialt stöd och vägledning, Funktion och resultat styr utförande, Betydelsen av personliga egenskaper och mentalitet, Träningsprogram underlättar hemträningen. Slutsats: Upplevelsen av följsamheten till rehabilitering efter total höftplastik i dagkirurgi utgörs av ett flertal individ- och omgivningsfaktorer såsom mentalitet, utfallsförväntningar, socialt stöd och väder. Resultat av denna studie tillför en ökad förståelse till bio-psyko-sociala upplevelser av följsamhet till rehabiliteringen efter dagkirurgisk total höftplastik i svensk kontext. / Background: Total hip arthroplasty is a surgery where the hip joint is replaced by a prosthesis. Nowadays the surgery is often carried out in day-surgery. The rehabilitation occurs at home with physiotherapeutic follow-up visits. Compliance to rehabilitation is important to regain function. Insight into patients’ experiences of rehabilitation can provide valuable new knowledge for physiotherapy with a behavioral medicine focus. Aim: To study how patients experience their compliance to rehabilitation after total hip arthroplasty in day-surgery. Method: Descriptive qualitative design with an inductive approach. Six patients who underwent total hip arthroplasty in day-surgery were included and participated in individual semi-structured interviews. A qualitative content analysis was applied to analyze data from the interviews. Results: The analysis resulted in 15 subcategories with the following five main categories: The importance of a good start, The significance of social support, Function and results control the performance, The meaning of personal characteristics and mentality, Exercise program facilitates the home rehabilitation. Conclusion: The experience of compliance to rehabilitation after total hip arthroplasty in day-surgery consists of several individual- and environmental factors such as mentality, outcome expectations, social support and weather. The result of this study expands the understanding of bio-psycho-social experiences of compliance to rehabilitation after total hip arthroplasty in day-surgery in a Swedish context.

Introduction : L’influence de l’Index de Masse Corporelle (IMC) sur la récupération des paramètres de la marche après prothèse totale de hanche (PTH) et de genou (PTG) est méconnue. Peu d' étude se sont intéressées à l'influence de l’IMC sur la récupération des amplitudes articulaires actives à la marche (AAA) ou de la vitesse de marche après PTH et PTG. Notre objectif était d’évaluer cet impact en préopératoire et en post-opératoire par une évaluation clinique et biomécanique. Notre hypothèse était que l’obésité (IMC>30kg/m2) serait un facteur péjoratif de récupération des paramètres de marche.Matériel et méthodes : Après avoir effectué une revue systématique de la littérature sur la récupération fonctionnelle après prothèses totales du membre inférieur (PTH et PTG) afin de nous assurer de l’originalité de notre travail et de sa pertinence nous avons réalisé 2 études prospectives indépendantes : en incluant 76 PTH chez des patients coxarthrosiques d’une part et 79 PTG chez des patients gonarthrosiques d’autre part. Tous les patients bénéficiaient d’une analyse quantifiée de la marche en préopératoire et en post-opératoire (à 6 mois pour les PTH et à un an pour les PTG). Un groupe de témoins sains appariés suivait le même protocole. La vitesse de la marche, l’AAA de hanche et de genou, ainsi que des scores fonctionnels et de qualité de vie étaient évalués, pour tous les paramètres le gain était calculé. Les patients étaient répartis en 2 groupes : patients non-obèses (G1) : IMC<30 et patients obèses (G2) : IMC≥30 dans chacune des cohortes. Des t-tests appariés étaient utilisés pour évaluer (1) les différences pré- et post-opératoires entre G1 et G2, puis les différences de gain entre G1 et G2. Enfin une régression linéaire uni- et multivariée recherchait les associations entre l’IMC, la vitesse de la marche et les AAA.Résultats Pour les 2 cohortes : en préopératoire, la vitesse de la marche et les AAA étaient significativement plus bas chez les obèses. En post-opératoire la vitesse de la marche et les AAA étaient significativement plus bas pour tous les patients opérés d’une PTG ou d’une PTH comparativement au groupe témoin. En pré-opératoire les obèses étaient plus symptomatiques. Une différence significative était retrouvée entre G1 et G2 concernant l’amélioration de la douleur en faveur des obèses (sur le gain de WOMAC douleur pour les PTG et d’EVA pour les PTH). Pour tous les autres paramètres les gains n’étaient pas différents entre G1 et G2. La régression uni- et multivariée ne montrait pas de relation significative entre la vitesse de la marche, les AAA et l’IMC.Conclusion : L’IMC n’a pas d’effet délétère direct sur la récupération des paramètres de marche après une PTH ou une PTG. En effet malgré une symptomatologie pré-opératoire plus forte les patients obèses présentent une amélioration comparable en termes de gain aux patients non-obèses. Cependant les paramètres de marche post-opératoire après une PTH ou une PTG demeurent significativement plus bas que ceux des témoins et ce quel que soit l’IMC des patients opérés, sans récupération ad integrum clinique ou biomécanique de leur fonction de la hanche ou du genou. Ainsi l’obésité semble présenter un effet similaire sur la récupération des paramètres de marche après une PTH ou une PTG. / Introduction : Body Mass Index (BMI) impact on gait recovery after total hip and total knee arthroplasty (THA and TKA) remains misunderstood. Few studies have analyzed the influence of BMI on the recovery of hip and knee range of motion (ROM) during gait or walking speed after THA and TKA. Our objective was to assess this impact preoperatively and post-operatively using both 3D gait analysis and clinical assessment. Our hypothesis was that obesity (BMI> 30kg /m2) would be a negative factor in the recovery of gait parameters.Material and methods: After conducting a systematic review of the literature on functional recovery after total prostheses of the lower limb (THA and TKA) to ensure the originality of this work and its relevance we conducted 2 independent prospective studies: including 76 THA in hip osteoarthritis patients on the one hand and 79 TKA in knee osteoarthritis patients on the other hand. All patients had a quantified gait analysis of preoperatively and postoperatively (at 6 months for THA and 1 year for TKA). A control group of matched healthy people followed the same protocol. The gait speed, ROM hip and knee, as well as functional and quality of life scores were evaluated, for all parameters the gain was calculated. Patients were divided into 2 groups in each cohort: non-obese patients (G1): BMI <30kg/m2 and obese patients (G2): BMI≥30kg/m2. Paired t-tests were used to evaluate the pre- and post-operative differences between G1 and G2, then the differences in gain between G1 and G2. Finally, a uni- and multivariate linear regression sought associations between BMI, gait speed, and ROM.Results: In both cohorts: preoperatively, gait speed and ROM were significantly lower in obese patients. Postoperatively, walking speed and ROM were significantly lower for all patients undergoing TKA or THA compared with the control group. Preoperatively obese patients were more symptomatic. A significant difference was found between G1 and G2 regarding pain improvement in favor of the obese (on the gain of WOMAC pain for TKA and analogic pain scale for THA). For all other parameters the gains were not different between G1 and G2. Uni- and multivariate regression showed no significant relationship between gait speed, ROM and BMI.Conclusion: BMI has no direct negative effect on recovery of walking parameters after THA or TKA. Indeed despite a higher preoperative symptomatology obese patients show a comparable improvement in terms of gain to non-obese patients clinically and biomechanically. However, postoperative gait parameters after THA or TKA remain significantly lower than those of controls, regardless of the BMI of patients without full clinical or biomechanical recovery. Though, obesity appears to have a similar effect on the gait parameters recovery after THA or TKA.