Class of 2017 Abstract / Objectives: The first aim is to assess efficacy of aspirin versus enoxaparin in preventing a venous thromboembolism (VTE) after a total knee arthroplasty (TKA) or total hip arthroplasty (THA) within 30 days after discharge. The second aim is to assess the safety of aspirin versus enoxaparin in preventing major bleeding events after a TKA or THA within 30 days after discharge. Methods: This study was a retrospective cohort study with data obtained from an online Veterans Affairs (VA) hospital database. For analysis, the primary outcome was assessed with a Chi-Square test, and the secondary outcome was reported with descriptive statistics.Results: Results: Demographics for 374 patients (TKA, n = 275; THA, n = 99): 90% male, average age of 65, average body mass index (BMI) of 32, 26% smokers, 72% had a history of hypertension, and 60% had a history of dyslipidemia. VTE events 30 days post-operatively: enoxaparin (n = 2), enoxaparin/aspirin (n = 1), and aspirin (n = 2) (P-value = 0.78). Safety events (major bleeding events): enoxaparin (n = 42), enoxaparin/aspirin (n = 7), and aspirin (n = 4). Conclusions: There was no significant difference between the treatment groups for VTE rate 30 days post- operation. The enoxaparin treatment group had the greatest number of safety events compared to the other groups.

A avaliação funcional após a artroplastia total de joelho (ATJ) tem o intuito de analisar como os resultados alcançados após a cirurgia impactam na qualidade de vida e função dos pacientes. Questionários subjetivos de auto percepção da função são os instrumentos mais utilizados, porém, tendem a superestimar a função física. Os testes de desempenho físico avaliam objetivamente o que o indivíduo é capaz de executar, mas avaliam tarefas isoladas que nem sempre refletem a mobilidade nas atividades de vida diária. Portanto, o objetivo deste estudo foi analisar o quanto a avaliação funcional, que incluiu questionários subjetivos e testes de desempenho físico, permite avaliar as mudanças ocorridas longitudinalmente após a ATJ e permite estabelecer fatores pré e pós-operatórios preditivos da função após um ano de cirurgia. Foi realizado estudo longitudinal prospectivo com 87 sujeitos (62 mulheres), idade 67±7 anos, IMC 33±5 kg/m2, submetidos à ATJ primária unilateral. A avaliação ocorreu no pré-operatório e 3, 6 e 12 meses após a cirurgia. Análise da covariância analisou as mudanças ao longo do tempo e a árvore de classificação e regressão estabeleceu os fatores preditivos. O questionário subjetivo WOMAC-função e os testes de desempenho físico timed up and go (TUG) e teste de caminhada de seis minutos (TC6) aos 12 meses de pós-operatório foram as variáveis primárias. A idade, índice de massa corpórea (IMC), WOMAC-dor, função pré-operatória e força muscular do joelho operado e não operado, tanto pré quanto pós-operatoriamente, foram estabelecidas como variáveis secundárias. Os resultados mostraram que WOMAC e o TUG atingiram platô de evolução aos três meses de pós-operatório, enquanto oTC6 alcançou o platô aos seis meses de pós-operatório. Com relação aos fatores pré- operatórios preditivos da função após 12 meses de cirurgia, indivíduos com TUG <=19 s e idade entre 62 e 70 anos alcançaram melhor pontuação no WOMAC-função. Sujeitos com força dos músculos extensores do joelho não operado >=99 Nm/kg e TC6 >328 m antes da cirurgia percorreram maior distância no TC6. Sujeitos com TUG =421 m no pré-operatório obtiveram melhor desempenho no TUG. Sobre os fatores pós-operatórios preditivos da função, sujeitos com WOMAC-dor < 1,5 pontos, TC6 >=410 m e TUG < 8 s apresentaram melhor pontuação do WOMAC-função. Sujeitos com TUG <9 s e força dos músculos extensores do joelho operado >=113 Nm/kg apresentaram melhor desempenho no TC6. Sujeitos com TC6 >=421 m e força dos músculos flexores do joelho não operado >=47Nm/kg foram mais rápidos na execução do TUG. Concluímos que os questionários subjetivos e os testes de desempenho físico apresentaram diferentes comportamentos de evolução ao longo de um ano de pós-operatório de ATJ. Sujeitos com melhor desempenho físico pré e pós-operatório apresentam melhor pontuação no WOMAC-função após a cirurgia e sujeitos com pior dor pós-operatória apresentaram pior percepção da função no mesmo período. Os fatores de maior predição dos testes de desempenho físico foram a função pré-operatória e a força muscular pré e pós-operatória. / The functional evaluation after total knee arthroplasty (TKA) is intended to analyze how the results achieved by the surgery affect the quality of life and function of patients. Subjective patient-report outcomes measures are the most commonly used instruments, but tend to overestimate physical function. Physical performance tests objectively evaluate what the individual is capable to perform, but evaluate isolated tasks that do not always reflect mobility in activities of daily living. Therefore, this study was aimed to analyze how functional evaluation, which encompassed subjective questionnaires and physical performance tests, enables us to evaluate the changes occurred longitudinally after TKA and to establish pre and post-operative predictive factors of this function one year after surgery. We performed a prospective longitudinal study with 87 individuals (62 women), age 66.9±6.66 years, BMI 32.5±5 kg/m2, submitted to unilateral primary TKA. The evaluation took place in the pre-operative period and 3, 6 and 12 months after surgery. The analysis of covariance assessed the changes over time, whereas the classification and regression tree established the predictive factors by considering the WOMAC-function questionnaire and the physical performance tests Timed Up and Go (TUG) and Six-minute Walk Test (6MWT) at 12 months post-operative as primary variables. Age, body mass index (BMI), WOMACpain, pre-operative function, and knee muscle strength, both pre-operatively and postoperatively, were set up as secondary variables. The results showed that the subjective questionnaires and the TUG tests reached a plateau of evolution at three months post-operative, while the 6MWT tests reached the plateau at six months postoperative. Regarding the pre-operative predictive factors of the function at 12 months after surgery, individuals with TUG<=19.3 seconds, aged between 62 and 70 years achieved a better score in the WOMAC-function one year after surgery. Individuals with non-operated knee extensor muscle strength >=99.43 Nm/kg and 6MWT >328 meters before surgery walked a longer distance in the 6MWT test. Individuals with TUG <12.3 seconds and 6MWT>=421 meters in the pre-operative period achieved better TUG performance. As for the post-operative predictive factors of the function, individuals with WOMAC-pain<1.5 points, 6MWT>=410.2 meters and TUG <7.90 seconds showed better scores of the WOMAC-function. Individuals with TUG<9.44seconds and operated knee extensor muscle strength>=112.8 Nm/kg showed better performance in the 6MWT test. Individuals with 6MWT>=421 meters and non-operated knee flexor strength>=47 Nm/kg were faster in executing the TUG test. We concluded that the subjective questionnaires and the physical performance tests showed different evolutionary behaviors during the first year after the TKA surgery. Individuals with better pre and post-operative physical performance show better scores in the WOMAC-function after surgery, while individuals with worse post-operative pain show worse perception of the function in the same period. The most predictive factors of the physical performance tests were pre-operative function and pre and post-operative muscle strength.

L’objectif de ce travail de thèse était d’évaluer les bénéfices thérapeutiques d’un entraînement par imagerie motrice chez les patients ayant subi une prothèse totale de genou unilatérale. Combiner l’imagerie motrice avec la physiothérapie classique a permis de diminuer la douleur et d’augmenter la force du quadriceps durant la phase aiguë, au 1er mois postopératoire. Durant la phase chronique, au 6ème mois postopératoire, l’imagerie motrice permettrait de corriger l’asymétrie de la marche, d’une part en augmentant la force du quadriceps ipsilatéral et, par conséquent, en accentuant la charge sur le genou opéré, et d’autre part en augmentant la flexion maximale du genou durant la phase oscillante. L’imagerie motrice pourrait également aider les personnes âgées après la prothèse totale du genou à monter les escaliers plus rapidement, en toute sécurité. Cela peut atténuer le risque de chute dans les escaliers et, par conséquent, diminuer la fréquence des blessures graves. En conclusion, intégrer l’imagerie motrice dans les programmes de rééducation après prothèse totale du genou primaire unilatérale est pertinent et prometteur / The primary aim of the present work was to determine the therapeutic benefits of a specific motor imagery training. Combining motor imagery with classical physical therapy was found to be effective in reducing pain and increasing quadriceps strength after total knee arthroplasty during the acute phase at the first month postoperatively. During the chronic phase, at the 6th month postoperatively, motor imagery might contribute to correct the asymmetry of gait by increasing the strength of the ipsilateral quadriceps and, consequently accentuating the weight loading on the operated knee, as well as by improving knee proprioception through an increase in the maximum knee flexion during the swing phase. MI might also help elderly people after total knee arthroplasty to climb stairs more quickly, easily, and safely. This could attenuate the risk of falls on stairs, and consequently decrease the frequency of major injuries. In summary, the integration of motor imagery in clinical rehabilitation programs after primary unilateral total knee arthroplasty is relevant and promising

Biocompatible sensors have been demonstrated using traditional microfabrication techniques modified for polymer substrates and utilize only materials suitable for implantation or bodily contact. Sensor arrays for the measurement of the load condition of polyethylene spacers in the total knee arthroplasty (TKA) prosthesis have been developed. Arrays of capacitive sensors are used to determine the three-dimensional strain within the polyethylene prosthesis component. Data from these sensors can be used to give researchers a better understanding of component motion, loading, and wear phenomena for a large range of activities. This dissertation demonstrates both analytically and experimentally the fabrication of these sensor arrays using biocompatible polymer substrates and dielectrics while preserving industry-standard microfabrication processing for micron-level resolution. An array of sensors for real-time measurement of pressure profiles is the long-term goal of this research. A custom design using capacitive-based sensors is an excellent selection for such measurement, giving high spatial resolution across the sensing surface and high load resolution for pressures applied normal to that surface while operating at low power.

The results of total knee arthroplasty are inferior in younger patients. The challenge today is therefore to develop designs and concepts that will last at least 25 years. This thesis has evaluated the fixation to bone of modern designs of knee prostheses uring RSA analysis. Coating implant surfaces with hydroxy-apatite have proven to enhance fixation to bone. Addition of screws for fixation of the tibial component enhances the fixation, but has negative side effects such as osteolysis around the screws, in turn leading to a higher risk of component loosening. The magnitude and pattern of migration was studied in a randomized study of uncemented tibial implants coated with hydroxy-apatite with and without additional screw fixation in patients younger than 65 years. The uncemented implants migrated initially more than the cemented implants that constituted the control group. Both uncemented groups stabilized at 3 monthes with no further migration, while the cemented implants showed a continuous migration up to the 2 year follow-up, indicating continuous bone resorption at the implant-bone interface, a fact that might lead to an increased risk of late implant loosening. This may not be a problem in older patients, but may have consequences for long-term fixation in younger patients. There was no difference between the two uncemented groups indicating that screws do not improve fixation. Hydroxy-apatite coated knee implants might be well suited for younger patients. Mobile bearing total knee arthroplasty theoretically uncouples the forces at the implant-bone interface, thus improving fixation of the implant to bone. The magnitude and pattern of migration of a cemented mobile bearing knee arthroplasty and a fixed bearing total knee arthroplasty was compared in a randomized study. The results showed that mobile bearings did not improve fixation. Trabecular metal, a new material recently introduced for total knee arthroplasty, has several theoretical advantages. Trabecular metal tibial implants were evaluated in a randomized study in patients younger than 60 years. The implants displayed the typical migration pattern for uncemented implants with greater migration initially followed by early stabilization. The majority of the trabecular metal implants subsided into the bone with no lift-off. Lift-off has the potential of exposing the interface to joint fluid with the potential risk of bone resorption and late loosening, and is commonly seen in metal-backed implants. The finding of absence of lift-off is regarded beneficial for uncemented fixation. Trabecular metal tibial implants might be suited for younger patients. The optimal mode of fixation of the femoral component is yet to be established. Comparing cemented femoral components with uncemented femoral components in a randomized study in patients younger than 60 years revealed no differences of the magnitude or the pattern of migration. Uncemented femoral component seems equally as good as cemented components in younger patients.

Traditionally, orthopaedic surgical training has primarily taken place in the operating room. Given the growing trend of decreasing resident work hours in North America and globally due to political mandate, training time in the operating room has generally been decreased. This has led to less operative exposure, teaching, and feedback for orthopaedic surgery residents. To solve this problem, a 3D serious game that was designed for the purpose of training orthopaedic surgery residents the steps comprising the total knee replacement procedure. Real-time, 3D graphical and sound rendering technologies are employed to provide sensory realism ensuring that the knowledge gained within the serious game can be more easily recalled and applied a real world scenario. A usability study to address user perceptions of the game’s ease of use, and the potential for learning and engagement was conducted. Results indicate that the serious game is easy to use, intuitive, and stimulating. / UOIT

Class of 2013 Abstract / Specific Aims:  To determine the efficacy of apixaban when compared to LMWH (enoxaparin) when used as thromboprophylaxis for patients undergoing total hip arthroplasty (THA), total knee arthroplasty (TKA), and medically ill patients  To determine the safety of apixaban when compared to LMWH (enoxaparin) when used as thromboprophylaxis for patients undergoing total hip arthroplasty (THA), total knee arthroplasty (TKA), and medically ill patients Methods: A systematic search of the literature for randomized controlled trials of apixaban thromboprophylaxis therapy versus enoxaparin was conducted using three databases: PubMed, EMBASE, and the Cochrane library. Data from five studies with 12,938 total patients were analyzed using Bayesian random effects meta-analysis. To evaluate efficacy, a composite of venous thromboembolism and death during follow-up was measured. To evaluate safety, major and total bleeding events were considered. Main Results: The odds ratio (OR) for the composite outcome of thromboembolism/death was 0.66 (95% CI: 0.33 to 1.29) for apixaban compared to enoxaparin, while there was a similar risk of major bleeding (OR=1.03, 95%CI: 0.36 to 3.73) and total bleeding (OR=0.92, 95%CI: 0.64 to 1.20). Conclusion: These results suggest a lack of clear superiority of apixaban relative to enoxaparin. Apixaban is an oral alternative with similar efficacy and safety to existing anticoagulant therapies.

Study Objective Although data from the Regulation of Coagulation in Orthopedic Surgery to Prevent Deep Venous Thrombosis and Pulmonary Embolism (RECORD) 1-4 trials have shown a similar postoperative bleeding risk between rivaroxban and enoxaparin in patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA), anecdotal observations from local institutions have suggested that postoperative bleeding rates seemed higher in patients who received rivaroxaban than those reported in the RECORD trials. Thus, the objective of this pilot study was to assess postoperative bleeding events observed in clinical practice in patients receiving rivaroxaban after undergoing THA and TKA and to compare their results with those published in the RECORD trials. Design Retrospective cohort study with a comparator group of patients from the RECORD 1-4 trials. Setting Two institutions within a regional health care system. Patients Four hundred forty adults who received at least one dose of rivaroxaban 10 mg daily after undergoing THA or TKA in the two institutions between August 2011 and October 2013 (cohort group), and 6183 patients who received rivaroxaban in the RECORD 1-4 trials (comparator group). Measurements and Main Results Postoperative bleeding was assessed in the cohort patients versus the patients in the RECORD trials. The primary outcome, occurrence of any postoperative bleeding, was a composite of major and clinically relevant nonmajor bleeding as defined in the RECORD trials. Any postoperative bleeding occurred in 6.8% of the cohort patients versus 3.2% of the RECORD trial patients (p<0.0001); 1.4% of the cohort patients versus 0.38% of the RECORD trial patients suffered a major bleed (p=0.013). Within defined major bleeding, bleeding leading to reoperation and clinically overt extrasurgical site bleeding resulting in either a hemoglobin level decrease of at least 2 g/dl or transfusion of 2 units or greater of packed red blood cells were reported in 0.68% versus 0.19% (p=0.073) and 0.68% versus 0.13% (p=0.032), respectively, of the cohort patients versus the RECORD trial patients. Conclusion Overall, any postoperative bleeding in the cohort patients occurred significantly more frequently than that observed in the RECORD trial patients. The major bleeding rate was also significantly higher in the cohort patients, influenced by higher rates of bleeding leading to reoperation and clinically overt extrasurgical site bleeding resulting in either a hemoglobin decrease of at least 2 g/dl or transfusion of two units or greater of packed red blood cells. These findings from our pilot study are thought provoking and, thus, invite further investigation.

京都大学 / 0048 / 新制・論文博士 / 博士(医学) / 乙第12919号 / 論医博第2094号 / 新制||医||1009(附属図書館) / 32129 / (主査)教授 戸口田 淳也, 教授 妻木 範行, 教授 安達 泰治 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DGAM

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第21674号 / 医博第4480号 / 新制||医||1036(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 安達 泰治, 教授 黒田 知宏, 教授 戸口田 淳也 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM