Can heart rate variability data from the Apple Watch electrocardiogram quantify stress?

Chronic stress has become an epidemic with negative health risks including cardiovascular disease, hypertension, and diabetes. Traditional methods of stress measurement and monitoring typically relies on self-reporting. However, wearable smart technologies offer a novel strategy to continuously and non-invasively collect objective health data in the real-world. A novel electrocardiogram (ECG) feature has recently been introduced to the Apple Watch device. Interestingly, ECG data can be used to derive Heart Rate Variability (HRV) features commonly used in the identification of stress, suggesting that the Apple Watch ECG app could potentially be utilized as a simple, cost-effective, and minimally invasive tool to monitor individual stress levels. Here we collected ECG data using the Apple Watch from 36 health participants during their daily routines. Heart rate variability (HRV) features from the ECG were extracted and analyzed against self-reported stress questionnaires based on the DASS-21 questionnaire and a single-item LIKERT-type scale. Repeated measures ANOVA tests did not find any statistical significance. Spearman correlation found very weak correlations (p < 0.05) between several HRV features and each questionnaire. The results indicate that the Apple Watch ECG cannot be used for quantifying stress with traditional statistical methods, although future directions of research (e.g., use of additional parameters and Machine Learning) could potentially improve stress quantification with the device.

Using apple watch ECG data for heart rate variability monitoring and stress prediction: A pilot study.

Stress is an increasingly prevalent mental health condition that can have serious effects on human health. The development of stress prediction tools would greatly benefit public health by allowing policy initiatives and early stress-reducing interventions. The advent of mobile health technologies including smartphones and smartwatches has made it possible to collect objective, real-time, and continuous health data. We sought to pilot the collection of heart rate variability data from the Apple Watch electrocardiograph (ECG) sensor and apply machine learning techniques to develop a stress prediction tool. Random Forest (RF) and Support Vector Machines (SVM) were used to model stress based on ECG measurements and stress questionnaire data collected from 33 study participants. Data were stratified into socio-demographic classes to further explore our prediction model. Overall, the RF model performed slightly better than SVM, with results having an accuracy within the low end of state-of-the-art. Our models showed specificity in their capacity to assess "no stress" states but were less successful at capturing "stress" states. Overall, the results presented here suggest that, with further development and refinement, Apple Watch ECG sensor data could be used to develop a stress prediction tool. A wearable device capable of continuous, real-time stress monitoring would enable individuals to respond early to changes in their mental health. Furthermore, large-scale data collection from such devices would inform public health initiatives and policies.

A conceptual IoT-based early-warning architecture for remote monitoring of COVID-19 patients in wards and at home.

Due to the COVID-19 pandemic, health services around the globe are struggling. An effective system for monitoring patients can improve healthcare delivery by avoiding in-person contacts, enabling early-detection of severe cases, and remotely assessing patients' status. Internet of Things (IoT) technologies have been used for monitoring patients' health with wireless wearable sensors in different scenarios and medical conditions, such as noncommunicable and infectious diseases. Combining IoT-related technologies with early-warning scores (EWS) commonly utilized in infirmaries has the potential to enhance health services delivery significantly. Specifically, the NEWS-2 has been showing remarkable results in detecting the health deterioration of COVID-19 patients. Although the literature presents several approaches for remote monitoring, none of these studies proposes a customized, complete, and integrated architecture that uses an effective early-detection mechanism for COVID-19 and that is flexible enough to be used in hospital wards and at home. Therefore, this article's objective is to present a comprehensive IoT-based conceptual architecture that addresses the key requirements of scalability, interoperability, network dynamics, context discovery, reliability, and privacy in the context of remote health monitoring of COVID-19 patients in hospitals and at home. Since remote monitoring of patients at home (essential during a pandemic) can engender trust issues regarding secure and ethical data collection, a consent management module was incorporated into our architecture to provide transparency and ensure data privacy. Further, the article details mechanisms for supporting a configurable and adaptable scoring system embedded in wearable devices to increase usefulness and flexibility for health care professions working with EWS.

Tanning-Elicited Variations in the Ultraviolet Absorption Spectra of the Cutaneous Tissues: Skin Photobiology and Photomedicine Implications.

When ultraviolet radiation is absorbed within the cutaneous tissues, it can trigger a number of phenomena that can have detrimental or beneficial consequences to an individual's health. Tanning is among the most visually noticeable of these phenomena. It may result in significant changes in skin pigmentation and thickness. These spectrally-dependent physiological responses, in turn, can elicit variations in the ultraviolet absorption profiles of the cutaneous tissues and, consequently, alter the occurrence of other ultraviolet-induced photobiological processes such as the breaking of DNA strands and the synthesis of previtamin D3. These tanning-elicited variations in the cutaneous tissues' absorption profiles is often tied to the increased presence of melanin throughout these tissues. However, during the tanning, shifts in the relative content of this pigment within certain skin layers can also be observed. In particular, the stratum basale, the innermost epidermal layer where melanogenesis takes place, can have its relative melanin content significantly reduced in comparison with other epidermal layers. Since the aforementioned photobiological phenomena are preferentially brought about within this layer, such pigmentation shifts may have a more pivotal role in skin photobiology than has been assumed to date. Accordingly, in this work, we investigate the impact of spectrally-dependent tanning-elicited physiological responses, with a particular focus on the inter-layer melanin distribution patterns, on the absorption profiles of the main cutaneous tissues. We also examine how variations in these absorption profiles may alter the outcomes of photo-triggered phenomena associated with the onset of different medical conditions. Our findings are expected to contribute to the advance of the current understanding about skin photobiology, which is indispensable for the success of photomedicine initiatives involving this highly complex organ.

A face recognition software framework based on principal component analysis.

Face recognition, as one of the major biometrics identification methods, has been applied in different fields involving economics, military, e-commerce, and security. Its touchless identification process and non-compulsory rule to users are irreplaceable by other approaches, such as iris recognition or fingerprint recognition. Among all face recognition techniques, principal component analysis (PCA), proposed in the earliest stage, still attracts researchers because of its property of reducing data dimensionality without losing important information. Nevertheless, establishing a PCA-based face recognition system is still time-consuming, since there are different problems that need to be considered in practical applications, such as illumination, facial expression, or shooting angle. Furthermore, it still costs a lot of effort for software developers to integrate toolkit implementations in applications. This paper provides a software framework for PCA-based face recognition aimed at assisting software developers to customize their applications efficiently. The framework describes the complete process of PCA-based face recognition, and in each step, multiple variations are offered for different requirements. Some of the variations in the same step can work collaboratively and some steps can be omitted in specific situations; thus, the total number of variations exceeds 150. The implementation of all approaches presented in the framework is provided.

Convergence of Precision Medicine and Public Health Into Precision Public Health: Toward a Big Data Perspective.

The field of precision medicine explores disease treatments by looking at genetic, socio-environmental, and clinical factors, thus trying to provide a holistic view of a person's health. Public health, on the other hand, is focused on improving the health of populations through preventive strategies and timely interventions. With recent advances in technology, we are able to collect, analyze and store for the first-time large volumes of real-time, diverse and continuous health data. Typically, the field of precision medicine deals with a huge amount of data from few individuals; public health, on the other hand, deals with limited data from a population. With the coming of Big Data, the fields of precision medicine and public health are converging into precision public health, the study of biological and genetic factors supported by large amounts of population data. In this paper, we explore through a comprehensive review the data types and use cases found in precision medicine and public health. We also discuss how these data types and use cases can converge toward precision public health, as well as challenges and opportunities provided by research and analyses of health data.

Knowledge reuse in software projects: Retrieving software development Q&A posts based on project task similarity.

Software developers need to cope with a massive amount of knowledge throughout the typical life cycle of modern projects. This knowledge includes expertise related to the software development phases (e.g., programming, testing) using a wide variety of methods and tools, including development methodologies (e.g., waterfall, agile), software tools (e.g., Eclipse), programming languages (e.g., Java, SQL), and deployment strategies (e.g., Docker, Jenkins). However, there is no explicit integration of these various types of knowledge with software development projects so that developers can avoid having to search over and over for similar and recurrent solutions to tasks and reuse this knowledge. Specifically, Q&A sites such as Stack Overflow are used by developers to share software development knowledge through posts published in several categories, but there is no link between these posts and the tasks developers perform. In this paper, we present an approach that (i) allows developers to associate project tasks with Stack Overflow posts, and (ii) recommends which Stack Overflow posts might be reused based on task similarity. We analyze an industry dataset, which contains project tasks associated with Stack Overflow posts, looking for the similarity of project tasks that reuse a Stack Overflow post. The approach indicates that when a software developer is performing a task, and this task is similar to another task that has been associated with a post, the same post can be recommended to the developer and possibly reused. We believe that this approach can significantly advance the state of the art of software knowledge reuse by supporting novel knowledge-project associations.

Sentimentos de mulheres com depressão pós-parto frente ao aleitamento materno / Feelings of women with postpartum depression in front of maternal breastfeeding

Objetivo: descrever sentimentos de mulheres com depressão pós-parto frente ao aleitamento materno. Metodologia: estudo qualitativo, descritivo e exploratório, com 20 mulheres com depressão pós-parto, entre abril e maio de 2017 em Fortaleza- CE. Para coletar dados realizou-se entrevista, roteiro sociodemográfico e obstétrico e relatos gravados e analisados por método de Bardin. Resultados: as dificuldades da depressão pós-parto no aleitamento são: falta de condições psicológicas, desencantamento e sentimentos como estresse, medo e tristeza. Conclusão: Constatou-se que mulheres com depressão pósparto sofreram impacto negativo durante o aleitamento, é essencial a atenção a sentimentos depressivos entre puérperas, devido forte relação ao desmame precoce. (AU)

Objective: To describe the feelings of women with postpartum depression in the face of breastfeeding. Methodology: This is a qualitative, descriptive and exploratory study, carried out in Fortaleza-CE, with 20 women who have or had postpartum depression. Results: The difficulties of postpartum depression in breastfeeding according to the interviewees were: lack of psychological conditions, difficulty in contact with the child, disenchantment, and feelings such as stress, fear, sadness, involved in the moment of breastfeeding. Conclusion: The present study found that women with postpartum depression had a negative impact during breastfeeding. More attention is needed to the mental health of the women, considering the depressive symptoms present in puerperas and the strong association with the shorter breastfeeding time. (AU)

Objetivo: describir los sentimientos de mujeres con depresión posparto frente a la lactancia materna. Metodología: Se trata de un estudio cualitativo, descriptivo y exploratorio, realizado en Fortaleza-CE, con 20 mujeres que tienen o tuvieron depresión posparto. Resultados: Las dificultades de la depresión posparto en la lactancia materna según las entrevistadas fueron: falta de condiciones psicológicas, dificultad en el contacto con el niño, desencanto, y sentimientos como estrés, miedo, tristeza, involucrados en el momento de la lactancia. Conclusión: El presente estudio constató que las mujeres con depresión posparto sufrieron un impacto negativo durante la lactancia. Se hace necesaria una mayor atención a la salud mental de las mujeres, considerando los síntomas depresivos presentes en puérperas y la fuerte asociación con el menor tiempo de lactancia materna. (AU)

Characterization of hip and knee arthroplasties and factors associated with infection / Caracterização de artroplastias de quadril e joelho e fatores associados à infecção

To characterize arthroplasty procedures, calculate the surgical infection rate and identify related risk factors. METHODS: This was a retrospective cohort study. Data on operations performed between 2010 and 2012 were gathered from documental sources and were analyzed with the aid of statistical software, using Fisher's exact test, Student'sttest and the nonparametric Mann-Whitney and Wilcoxon tests. RESULTS: 421 total arthroplasty procedures performed on 346 patients were analyzed, of which 208 were on the knee and 213 on the hip. It was found that 18 patients (4.3%) were infected. Among these, 15 (83.33%) were reoperated and 2 (15.74%) died. The prevalence of infection in primary total hip arthroplasty procedures was 3%; in primary total knee arthroplasty, 6.14%; and in revision of total knee arthroplasty, 3.45%. Staphylococcus aureuswas prevalent. The length of the surgical procedure showed a tendency toward being a risk factor ( p= 0.067). CONCLUSION: The prevalence of infection in cases of primary total knee arthroplasty was greater than in other cases. No statistically significant risk factors for infection were identified.

Caracterizar as artroplastias, calcular a taxa de infecção cirúrgica e identificar fatores de risco relacionados. MÉTODOS: Estudo de coorte retrospectivo. Os dados das cirurgias feitas entre 2010 e 2012 foram coletados em fontes documentais e analisados com auxílio de programa estatístico e testes exato de Fisher, tde Student e não paramétrico de Mann-Whitney e Wilcoxon. RESULTADOS: Foram analisadas 421 artroplastias totais em 346 pacientes, 208 de joelho e 213 de quadril; 18 (4,3%) pacientes infectaram; entre esses, 15(83,33%) foram reoperados e dois (15,74%) evoluíram para óbito. A prevalência de infecção em artroplastia total de quadril primária foi de 3%, em artroplastia total de joelho primária de 6,14% e em revisão de artroplastia total de joelho de 3,45%; Staphylococcus aureusfoi prevalente. O tempo de duração da cirurgia indicou uma tendência como fator de risco (p = 0,067). CONCLUSÃO: A prevalência de infecção em artroplastia total de joelho primária foi superior às demais e não foram identificados fatores de risco para infecção com significância estatística.

Alignment of the tibial component in total knee arthroplasty procedures using an intramedullary or extramedullary guide: double-blind randomized prospective study.

OBJECTIVES: To evaluate the results obtained through using an intramedullary or extramedullary guide for sectioning the tibia in total knee arthroplasty procedures, with a view to identifying the accuracy of these guides and whether one might be superior to the other. METHODS: This was a randomized double-blind prospective study on 41 total knee arthroplasty procedures performed between August 2011 and March 2012. The angle between the base of the tibial component and the mechanical axis of the tibia was measured during the immediate postoperative period by means of radiography in anteroposterior view on the tibia that encompassed the knee and ankle. RESULTS: There was no demographic difference between the two groups evaluated. The mean alignment of the tibial component in the patients of group A (intramedullary) was 90.3° (range: 84-97°). In group B (extramedullary), it was 88.5° (range: 83-94°). CONCLUSION: In our study, we did not find any difference regarding the precision or accuracy of either of the guides. Some patients present an absolute or relative contraindication against using one or other of the guides. However, for the other cases, neither of the guides was superior to the other one.

OBJETIVOS: Avaliar os resultados obtidos com o uso de guia intramedular ou extramedular para o corte tibial em artroplastias totais do joelho, com vistas a identificar sua acurácia e a superioridade de um em relação ao outro. MÉTODOS: Estudo prospectivo, randomizado, duplo cego de 41 artroplastias totais de joelho feitas entre agosto de 2011 e março de 2012. Foi medido o ângulo entre a base do componente tibial e o eixo mecânico da tíbia no período pós-operatório imediato por meio de radiografia em incidência anteroposterior da tíbia que englobou joelho e tornozelo. RESULTADOS: Não houve diferença demográfica entre os dois grupos avaliados. O alinhamento médio do componente tibial nos pacientes do grupo A (intramedular) foi de 90,3° (84°-97°). No grupo B (extramedular), foi de 88,5° (83°-94°). CONCLUSÃO: Não encontramos, em nosso estudo, diferença quanto à precisão ou acurácia de qualquer um dos guias. Alguns pacientes apresentam contraindicação, absoluta ou relativa, para o uso de um ou outro guia. Todavia, para os demais casos, não há superioridade de algum deles.

Alignment of the tibial component in total knee arthroplasty procedures using an intramedullary or extramedullary guide: double-blind randomized prospective study / Alinhamento do componente tibial em artroplastia total do joelho com o uso de guia intramedular ou extramedular: um estudo prospectivo, randomizado, duplo cego

OBJECTIVES: To evaluate the results obtained through using an intramedullary or extramedullary guide for sectioning the tibia in total knee arthroplasty procedures, with a view to identifying the accuracy of these guides and whether one might be superior to the other. METHODS: This was a randomized double-blind prospective study on 41 total knee arthroplasty procedures performed between August 2011 and March 2012. The angle between the base of the tibial component and the mechanical axis of the tibia was measured during the immediate postoperative period by means of radiography in anteroposterior view on the tibia that encompassed the knee and ankle. RESULTS: There was no demographic difference between the two groups evaluated. The mean alignment of the tibial component in the patients of group A (intramedullary) was 90.3° (range: 84-97°). In group B (extramedullary), it was 88.5° (range: 83-94°). CONCLUSION: In our study, we did not find any difference regarding the precision or accuracy of either of the guides. Some patients present an absolute or relative contraindication against using one or other of the guides. However, for the other cases, neither of the guides was superior to the other one. .

OBJETIVOS: Avaliar os resultados obtidos com o uso de guia intramedular ou extramedular para o corte tibial em artroplastias totais do joelho, com vistas a identificar sua acurácia e a superioridade de um em relação ao outro. MÉTODOS: Estudo prospectivo, randomizado, duplo cego de 41 artroplastias totais de joelho feitas entre agosto de 2011 e março de 2012. Foi medido o ângulo entre a base do componente tibial e o eixo mecânico da tíbia no período pós-operatório imediato por meio de radiografia em incidência anteroposterior da tíbia que englobou joelho e tornozelo. RESULTADOS: Não houve diferença demográfica entre os dois grupos avaliados. O alinhamento médio do componente tibial nos pacientes do grupo A (intramedular) foi de 90,3° (84°-97°). No grupo B (extramedular), foi de 88,5° (83°-94°). CONCLUSÃO: Não encontramos, em nosso estudo, diferença quanto à precisão ou acurácia de qualquer um dos guias. Alguns pacientes apresentam contraindicação, absoluta ou relativa, para o uso de um ou outro guia. Todavia, para os demais casos, não há superioridade de algum deles. .

Characterization of hip and knee arthroplasties and factors associated with infection.

OBJECTIVE: To characterize arthroplasty procedures, calculate the surgical infection rate and identify related risk factors. METHODS: This was a retrospective cohort study. Data on operations performed between 2010 and 2012 were gathered from documental sources and were analyzed with the aid of statistical software, using Fisher's exact test, Student's t test and the nonparametric Mann-Whitney and Wilcoxon tests. RESULTS: 421 total arthroplasty procedures performed on 346 patients were analyzed, of which 208 were on the knee and 213 on the hip. It was found that 18 patients (4.3%) were infected. Among these, 15 (83.33%) were reoperated and 2 (15.74%) died. The prevalence of infection in primary total hip arthroplasty procedures was 3%; in primary total knee arthroplasty, 6.14%; and in revision of total knee arthroplasty, 3.45%. Staphylococcus aureus was prevalent. The length of the surgical procedure showed a tendency toward being a risk factor (p = 0.067). CONCLUSION: The prevalence of infection in cases of primary total knee arthroplasty was greater than in other cases. No statistically significant risk factors for infection were identified.

OBJETIVO: Caracterizar as artroplastias, calcular a taxa de infecção cirúrgica e identificar fatores de risco relacionados. MÉTODOS: Estudo de coorte retrospectivo. Os dados das cirurgias feitas entre 2010 e 2012 foram coletados em fontes documentais e analisados com auxílio de programa estatístico e testes exato de Fisher, t de Student e não paramétrico de Mann­Whitney e Wilcoxon. RESULTADOS: Foram analisadas 421 artroplastias totais em 346 pacientes, 208 de joelho e 213 de quadril; 18 (4,3%) pacientes infectaram; entre esses, 15(83,33%) foram reoperados e dois (15,74%) evoluíram para óbito. A prevalência de infecção em artroplastia total de quadril primária foi de 3%, em artroplastia total de joelho primária de 6,14% e em revisão de artroplastia total de joelho de 3,45%; Staphylococcus aureus foi prevalente. O tempo de duração da cirurgia indicou uma tendência como fator de risco (p = 0,067). CONCLUSÃO: A prevalência de infecção em artroplastia total de joelho primária foi superior às demais e não foram identificados fatores de risco para infecção com significância estatística.

Evaluation of the results from proximal fixation of uncemented conical femoral components in Dorr type C femurs / Avaliação dos resultados de componente femoral cônico de fixação proximal não cimentado em fêmur tipo C de Dorr

OBJECTIVE: To evaluate the results from proximal fixation of uncemented conical femoral components in patients with a type C proximal femur and compare them with the results obtained from type A and B femurs. METHODS: This was a retrospective study on 87 patients with 90 uncemented total hip arthroplasty procedures. Three patients (three hips) were excluded because their follow-up lasted for less than two years. The follow-up ranged from 2 to 4.3 years and the mean was 2.8 years. The Bicontact femoral implant model was used. The preoperative radiographs were evaluated, the femurs were classified as Dorr types A, B or C and the cortical indices were measured. The patients were evaluated clinically by means of the Harris Hip Score (HHS), before the surgery and at the last follow-up. The sequences of postoperative radiographs were compared regarding stability, complications and any signs of osseointegration of the femoral prosthesis. RESULTS: Among the 87 hips with follow-up greater than two years, 32 femurs were type A (37%), 37 type B (42%) and 18 type C (21%). Before the operation, the mean HHS was 39.4 for types A and B and 38.8 for type C. At the last follow-up, the mean HHS was 89.8 for types A and B and 86 for type C. None of the 87 femoral components had been revised by the time of the last follow-up; all of them were considered stable. In 86 cases, the radiographs showed signs of osseointegration. CONCLUSION: There were no significant differences in the clinical results or in the fixation (and osseointegration) of conical uncemented femoral prostheses with proximal porosity, among femurs with different types of femoral morphology according to the Dorr classification. This conclusion may vary if another implant model were to be used...

OBJETIVO: avaliar os resultados de componentes femorais cônicos não cimentados de fixação proximal em pacientes com fêmur proximal tipo C e compará-los com os resultados obtidos em fêmures tipos A e B. MÉTODOS: estudo retrospectivo de 87 pacientes com 90 ATQs não cimentadas. Três pacientes (três ATQs) foram excluídos por seguimento menor do que dois anos. Houve seguimento de dois a 4,3 anos e média de 2,8 anos. Foram usados implantes femorais modelo Bicontact. As radiografias pré-operatórias foram avaliadas e classificados os fêmures nos tipos A, B ou C de Dorr, além da aferição dos índices corticais (IC). Clinicamente os pacientes foram avaliados por meio do Harris Hip Score (HHS), antes da cirurgia e no último seguimento. Compararam-se as radiografias pós-operatórias sequenciais quanto a estabilidade, complicações e sinais de osteointegração ou não da prótese femoral. RESULTADOS: dos 87 quadris com seguimento maior do que dois anos, 32 fêmures eram tipo A (37%), 37 tipo B (42%) e 18 tipo C (21%). No pré-operatório a média do HHS foi de 39,4 nos tipos A e B e 38,8 no tipo C. No último seguimento o HHS em média foi de 89,8 nos tipos A e B e 86 no tipo C. Nenhum dos 87 componentes femorais foi revisado até o último seguimento. Todos foram considerados estáveis. As radiografias de 86 demonstraram sinais de osteointegração. CONCLUSÃO: não houve diferença significativa nos resultados clínicos e na fixação (e osteointegração) de próteses femorais não cimentadas cônicas, com porosidade proximal, em fêmures dos diferentes tipos de morfologia femoral de acordo com a classificação de Dorr. Essa conclusão pode variar em caso de uso de outro modelo de implante...

Evaluation of the results from proximal fixation of uncemented conical femoral components in Dorr type C femurs.

OBJECTIVE: To evaluate the results from proximal fixation of uncemented conical femoral components in patients with a type C proximal femur and compare them with the results obtained from type A and B femurs. METHODS: This was a retrospective study on 87 patients with 90 uncemented total hip arthroplasty procedures. Three patients (three hips) were excluded because their follow-up lasted for less than two years. The follow-up ranged from 2 to 4.3 years and the mean was 2.8 years. The Bicontact femoral implant model was used. The preoperative radiographs were evaluated, the femurs were classified as Dorr types A, B or C and the cortical indices were measured. The patients were evaluated clinically by means of the Harris Hip Score (HHS), before the surgery and at the last follow-up. The sequences of postoperative radiographs were compared regarding stability, complications and any signs of osseointegration of the femoral prosthesis. RESULTS: Among the 87 hips with follow-up greater than two years, 32 femurs were type A (37%), 37 type B (42%) and 18 type C (21%). Before the operation, the mean HHS was 39.4 for types A and B and 38.8 for type C. At the last follow-up, the mean HHS was 89.8 for types A and B and 86 for type C. None of the 87 femoral components had been revised by the time of the last follow-up; all of them were considered stable. In 86 cases, the radiographs showed signs of osseointegration. CONCLUSION: There were no significant differences in the clinical results or in the fixation (and osseointegration) of conical uncemented femoral prostheses with proximal porosity, among femurs with different types of femoral morphology according to the Dorr classification. This conclusion may vary if another implant model were to be used.

OBJETIVO: avaliar os resultados de componentes femorais cônicos não cimentados de fixação proximal em pacientes com fêmur proximal tipo C e compará-los com os resultados obtidos em fêmures tipos A e B. MÉTODOS: estudo retrospectivo de 87 pacientes com 90 ATQs não cimentadas. Três pacientes (três ATQs) foram excluídos por seguimento menor do que dois anos. Houve seguimento de dois a 4,3 anos e média de 2,8 anos. Foram usados implantes femorais modelo Bicontact. As radiografias pré-operatórias foram avaliadas e classificados os fêmures nos tipos A, B ou C de Dorr, além da aferição dos índices corticais (IC). Clinicamente os pacientes foram avaliados por meio do Harris Hip Score (HHS), antes da cirurgia e no último seguimento. Compararam-se as radiografias pós-operatórias sequenciais quanto a estabilidade, complicações e sinais de osteointegração ou não da prótese femoral. RESULTADOS: dos 87 quadris com seguimento maior do que dois anos, 32 fêmures eram tipo A (37%), 37 tipo B (42%) e 18 tipo C (21%). No pré-operatório a média do HHS foi de 39,4 nos tipos A e B e 38,8 no tipo C. No último seguimento o HHS em média foi de 89,8 nos tipos A e B e 86 no tipo C. Nenhum dos 87 componentes femorais foi revisado até o último seguimento. Todos foram considerados estáveis. As radiografias de 86 demonstraram sinais de osteointegração. CONCLUSÃO: não houve diferença significativa nos resultados clínicos e na fixação (e osteointegração) de próteses femorais não cimentadas cônicas, com porosidade proximal, em fêmures dos diferentes tipos de morfologia femoral de acordo com a classificação de Dorr. Essa conclusão pode variar em caso de uso de outro modelo de implante.

Componente tibial na revisão da artroplastia do joelho: comparação entre fixação cimentada e híbrida / Tibial component in revision of total knee arthroplasty: comparison between cemented and hybrid fixation

OBJETIVO: Comparar os resultados clínicos, radiográficos e de seguimento a médio prazo de dois métodos de fixação do componente tibial nas cirurgias de revisão de prótese total do joelho: cimentada (bandeja e haste) e híbrida (bandeja cimentada e haste que preenche o canal não cimentada e não porosa). MÉTODOS: Entre agosto de 1999 e novembro de 2005, 30 cirurgias de revisão de artroplastia total do joelho foram realizadas em 26 pacientes, sendo divididas em: grupo I: fixação cimentada (N = 21); grupo II: híbrida (N = 9). O tempo médio de acompanhamento foi de 52 meses, e não houve perda de seguimento pós-operatório. RESULTADOS: Não foram observadas diferenças nos resultados dos valores dos questionários da Womac e do Knee Society Score entre os dois grupos. Um paciente do grupo I apresentou sinais radiográficos de soltura. Dois pacientes (um de cada grupo) referiram dor na região diafisária, compatível com o local da ponta das hastes. O sinal radiográfico de "pedestal" esteve presente em 89 por cento dos joelhos com hastes não cimentadas e em nenhum com haste cimentada. CONCLUSÃO: A análise comparativa entre os dois métodos não mostrou diferenças nos parâmetros clínico, radiográfico e de sobrevida da artroplastia.

OBJECTIVE: To compare the clinical, radiographic and medium-term follow-up results from two fixation methods for the tibial component in revision procedures on total knee prostheses: cemented (tray and stem) and hybrid (cemented tray and uncemented, nonporous canal-filling stem). METHODS: Between August 1999 and November 2005, 30 revision procedures on total knee arthroplasties were performed on 26 patients, who were divided between group I (cemented fixation; 21 knees) and group II (hybrid fixation; nine knees). The mean follow-up was 52 months and no patients were lost from the follow-up. RESULTS: No differences in the scores from the WOMAC and Knee Society questionnaires were observed between the two groups. One patient in group I presented radiographic signs of loosening. Two patients (one in each group) complained of pain in the diaphyseal region, compatible with the location of the stem tip. The pedestal radiographic sign was observed in 89 percent of the knees with uncemented stems and in none of the cemented group. CONCLUSION: The comparative analysis between the two methods did not show any differences regarding clinical and radiographic parameters, or arthroplasty survival.

Model human behavior: don't constrain it!

Healthcare processes are complex and highly variable from day to day. Healthcare process execution can be affected by any participant in a process, including clinicians, the patient, and the patient's family, as well as environmental factors such as clinician, staff, facility and equipment availability, and patient clinical status. However, only a few solutions exist that enable computer support for a process to address the full complexity and variability of healthcare processes. We have re-conceptualized workflow and developed an innovative process representation and execution framework based on concepts from software engineering, machine learning, complexity, and database management. This new framework frees processes to track human behavior, thereby releasing us from the constraints of past methods. Our approach is also serving as a new architecture for software systems.

TIBIAL COMPONENT IN REVISION OF TOTAL KNEE ARTHROPLASTY: COMPARISON BETWEEN CEMENTED AND HYBRID FIXATION.

OBJECTIVE: To compare the clinical, radiographic and medium-term follow-up results from two fixation methods for the tibial component in revision procedures on total knee prostheses: cemented (tray and stem) and hybrid (cemented tray and uncemented, nonporous canal-filling stem). METHODS: Between August 1999 and November 2005, 30 revision procedures on total knee arthroplasties were performed on 26 patients, who were divided between group I (cemented fixation; 21 knees) and group II (hybrid fixation; nine knees). The mean follow-up was 52 months and no patients were lost from the follow up. RESULTS: No differences in the scores from the WOMAC and Knee Society questionnaires were observed between the two groups. One patient in group I presented radiographic signs of loosening. Two patients (one in each group) complained of pain in the diaphyseal region, compatible with the location of the stem tip. The pedestal radiographic sign was observed in 89% of the knees with uncemented stems and in none of the cemented group. CONCLUSION: The comparative analysis between the two methods did not show any differences regarding clinical and radiographic parameters, or arthroplasty survival.

Fraturas periprotéticas em artroplastia total de joelho / Periprosthetic fractures in total knee arthroplasty

A associação do maior número de artroplastias totais de joelho com a maior expectativa de vida da população tem levado a mais complicações de longo prazo, que se somam à baixa qualidade óssea dos pacientes mais idosos e culminam, muitas vezes, em fraturas periprotéticas. Este complexo problema ortopédico tem apresentação clínica muito variável, podendo acometer quaisquer dos ossos do joelho e levar a resultados desastrosos, em virtude de sua difícil solução. O seu tratamento exige do ortopedista amplo conhecimento tanto de técnicas de artroplastia como de osteossíntese, além de elaborado arsenal terapêutico como, por exemplo, acesso a banco de ossos.

The increasing number of total knee arthroplasties, in combination with the population's longer life expectancy, has led to a greater number of long-term complications. These complications are also correlated with poor bone quality in the elderly and often result in periprosthetic fractures. This complex orthopedic problem has very diverse clinical presentation, possibly afflicting periprosthetic fracture may happen in any bone that constitutes the knee and, due to the difficulty of finding a solution, may lead to disastrous outcomes. The treatment demands broad knowledge from the orthopedic surgeon, not only regarding arthroplasty techniques, but also osteosynthesis, as well as an elaborate therapeutic including, for example, access to a bone bank.