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1.
J Med Ethics ; 2023 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-37945337

RESUMO

Aristotle's ethical system was guided by his vision of human flourishing (also, but potentially misleadingly, translated as happiness). For Aristotle, human flourishing was a rich holistic concept about a life lived well until its ending. Both living a long life and dying well were integral to the Aristotelian ideal of human flourishing. Using Aristotle's concept of human flourishing to inform the goals of medicine has the potential to provide guidance to clinical decision-makers regarding the provision of burdensome treatments, such as intensive care treatment, where pursuing a chance of survival must be balanced against the risk of exposing patients to a negative dying experience. By conceptually uniting potentially competing goals of medicine, such as prolonging life and the promotion of peaceful deaths, Aristotle's understanding of human flourishing creates an argument for the integration of palliative care considerations into intensive care decision-making and for advanced care planning with healthy patients.

2.
J Med Ethics ; 2023 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-37863648

RESUMO

In a recent paper, Braun argued for an autonomy-based approach to assisted suicide as a way to avoid the expressivist objection to assisted dying laws. In this paper, I will argue that an autonomy-based approach actually extends the expressivist objection to assisted dying because it is not possible for one agent to assist another in pursuit of a goal without expressing that it would be good for that goal to come about. Braun argued that assisted dying should be viewed purely as an individual's autonomous action, but this requires the assistance of the medical professional to be understood as that of a non-moral automaton, such as a suicide booth. Instead, it will be argued that a beneficent motivation to promote human flourishing provides moral reasons for both non-interference in the actions, for example, suicide, of competent agents and for considering whether assisting another agent with their goal will promote their flourishing.

3.
Am J Perinatol ; 2023 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-37207673

RESUMO

OBJECTIVE: This study aimed to compare the labor progress between individuals who received calcium channel blocker (CCB) and those who did not receive CCB during labor. STUDY DESIGN: This was a secondary analysis of a retrospective cohort study of individuals with chronic hypertension who underwent vaginal delivery at a tertiary care center from January 2010 to December 2020. We excluded individuals with prior uterine surgeries and a 5-minute Apgar score of less than 5. We used a repeated-measures regression with a third-order polynomial function to compare the average labor curves according to antihypertensive medication. Estimates of the median (5th-95th percentile) traverse times between two dilations were computed using interval-censored regression. RESULTS: Of 285 individuals with chronic hypertension, 88 (30.9%) received CCB. Individuals who received CCB during labor compared with those who did not were more likely to deliver at earlier gestational age and to have pregestational diabetes and superimposed preeclampsia (p < 0.01). The progress of labor in the latent phase was not found to be significantly different between both groups (median: 11.51 vs. 8.74 hours; p = 0.08). However, after stratification by parity, nulliparous individuals who received CCB during labor were more likely to have a longer latent phase of labor (median: 14.4 vs. 8.5 hours; p = 0.03) CONCLUSION: A calcium channel blocker may slow the latent phase of labor in individuals with chronic hypertension. Aiming to minimize intrapartum iatrogenic interventions, allowing adequate time for pregnant individuals during the latent phase of labor is especially important if individuals are on a calcium channel blocker. KEY POINTS: · Calcium channel blockers seem to be associated with a longer latent phase of labor.. · The effect of calcium channel blocker on labor was not observed in multiparous individuals.. · Allowing adequate labor time for individuals taking calcium channel blocker is important..

4.
Am J Perinatol ; 2023 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-37207676

RESUMO

OBJECTIVE: Superimposed preeclampsia (SIPE), defined as preeclampsia in individuals with chronic hypertension, is one of the most common complications, accounting for 13 to 40% of pregnancies with chronic hypertension. However, there are limited data regarding maternal outcomes of early- and late-onset SIPE in individuals with chronic hypertension. We hypothesized that early-onset SIPE was associated with increased odds of adverse maternal outcomes compared with late-onset SIPE. Therefore, we aimed to compare adverse maternal outcomes between individuals with early-onset SIPE and those with late-onset SIPE. STUDY DESIGN: This was a retrospective cohort study of pregnant individuals with SIPE who delivered at 22 weeks' gestation or greater at an academic institution. Early-onset SIPE was defined as the onset of SIPE before 34 weeks' gestation. Late-onset SIPE was defined as the onset of SIPE at or after 34 weeks' gestation. Our primary outcome was a composite of eclampsia, hemolysis, elevated liver enzymes, low platelet count (HELLP) syndrome, maternal death, placental abruption, pulmonary edema, SIPE with severe features, and thromboembolic disease. Maternal outcomes were compared between early- and late-onset SIPE. We used simple and multivariate logistic regression models to calculate crude and adjusted odds ratios (aOR) with 95% confidence intervals (95% CI). RESULTS: Of 311 individuals, 157 (50.5%) had early-onset SIPE, 154 (49.5%) had late-onset SIPE. There were significant differences in the proportions of obstetric complications, including the primary outcome, HELLP syndrome, SIPE with severe features, fetal growth restriction (FGR), and cesarean delivery between early- and late-onset SIPE. Compared with individuals with late-onset SIPE, those with early-onset SIPE had increased odds of the primary outcome (aOR: 3.28; 95% CI: 1.42-7.59), SIPE with severe features (aOR: 2.72; 95% CI: 1.25-5.90), FGR (aOR: 6.07; 95% CI: 3.25-11.36), and cesarean delivery (aOR 3.42; 95% CI: 2.03-5.75). CONCLUSION: Individuals with early-onset SIPE had higher odds of adverse maternal outcomes compared with those with late-onset SIPE. KEY POINTS: · We revealed the incidence of maternal outcomes in early- and late-onset SIPE.. · Severe features were common in individuals with SIPE.. · Early-onset SIPE was associated with increased adverse maternal outcomes compared with late-onset SIPE..

5.
Am J Perinatol ; 2023 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-37211009

RESUMO

OBJECTIVE: Risk factors of early- and late-onset preeclampsia among pregnant individuals with chronic hypertension are not well described in the literature. We hypothesized that early- and late-onset superimposed preeclampsia (SIPE) have different risk factors. Therefore, we aimed to examine the risk factors of early- and late-onset SIPE among individuals with chronic hypertension. STUDY DESIGN: This was a retrospective case-control study of pregnant individuals with chronic hypertension who delivered at 22 weeks' gestation or greater at an academic institution. Early-onset SIPE was defined as SIPE diagnosed before 34 weeks' gestation. To identify risk factors, we compared individuals' characteristics between individuals who developed early- and late-onset SIPE and those who did not. We then compared characteristics between individuals who developed early-onset SIPE and late-onset SIPE. Characteristics with p-values of less than 0.05 by bivariable variables were analyzed by simple and multivariable logistic regression models to calculate crude and adjusted odds ratios (aOR) and 95% confidence intervals (95% CI). Missing values were imputed with multiple imputation. RESULTS: Of 839 individuals, 156 (18.6%) had early-onset, 154 (18.4%) had late-onset SIPE and 529 (63.1%) did not have SIPE. The multivariate logistic regression model showed that serum creatinine ≥ 0.7 mg/dL compared to less than 0.7 mg/dL (aOR: 2.89 [95% CI: 1.63-5.13]), increase of creatinine (1.33 [1.16-1.53]), nulliparity compared to multiparity (1.77 [1.21-2.60]), and pregestational diabetes (1.70 [1.11-2.62]) were risk factors for early-onset SIPE. The multivariate logistic regression model showed that nulliparity compared to multiparity (1.53 [1.05-2.22]) and pregestational diabetes (1.74 [1.14-2.64]) was a risk factor for late-onset SIPE. Serum creatinine ≥ 0.7 mg/dL (2.90 [1.36-6.15]) and increase of creatinine (1.33 [1.10-1.60]) were significantly associated with early-onset SIPE compared to late-onset SIPE. CONCLUSION: Kidney dysfunction seemed to be associated with the pathophysiology of early-onset SIPE. Nulliparity and pregestational diabetes were common risk factors for both early- and late-onset SIPE. KEY POINTS: · Serum creatinine level was positively associated with early-onset superimposed preeclampsia (SIPE).. · Pregestational diabetes and nulliparity were associated with both early- and late-onset SIPE.. · The identification of risk factors may provide an opportunity to decrease the rates of SIPE..

6.
Am J Perinatol ; 40(11): 1163-1170, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37216976

RESUMO

OBJECTIVE: This study aimed to evaluate rates of superimposed preeclampsia in pregnant individuals with echocardiography-diagnosed cardiac geometric changes in the setting of chronic hypertension. STUDY DESIGN: This was a retrospective study of pregnant individuals with chronic hypertension who delivered singleton pregnancies at 20 weeks' gestation or greater at a tertiary care center. Analyses were limited to individuals who had an echocardiogram during any trimester. Cardiac changes were categorized as normal morphology, concentric remodeling, eccentric hypertrophy, and concentric hypertrophy according to the American Society of Echocardiography guidelines. Our primary outcome was early-onset superimposed preeclampsia defined as delivery at less than 34 weeks' gestation. Other secondary outcomes were also examined. Adjusted odds ratios (aORs) with 95% confidence intervals (95% CIs) were calculated, controlling for prespecified covariates. RESULTS: Of the 168 individuals who delivered from 2010 to 2020, 57 (33.9%) had normal morphology, 54 (32.1%) had concentric remodeling, 9 (5.4%) had eccentric hypertrophy, and 48 (28.6%) had concentric hypertrophy. Non-Hispanic black individuals presented over 76% of the cohort. Rates of the primary outcome in individuals with normal morphology, concentric remodeling, eccentric hypertrophy, and concentric hypertrophy were 15.8, 37.0, 22.2, and 41.7%, respectively (p = 0.01). Compared with individuals with normal morphology, individuals with concentric remodeling were more likely to have the primary outcome (aOR: 3.28; 95% CI: 1.28-8.39), fetal growth restriction (crude OR: 2.98; 95% CI: 1.05-8.43), and iatrogenic preterm delivery <34 weeks' gestation (aOR: 2.72; 95% CI: 1.15-6.40). Compared with individuals with normal morphology, individuals with concentric hypertrophy were more likely to have the primary outcome (aOR: 4.16; 95% CI: 1.57-10.97), superimposed preeclampsia with severe features at any gestational age (aOR: 4.75; 95% CI: 1.94-11.62), iatrogenic preterm delivery <34 weeks' gestation (aOR: 3.60; 95% CI: 1.47-8.81), and neonatal intensive care unit admission (aOR: 4.82; 95% CI: 1.90-12.21). CONCLUSION: Concentric remodeling and concentric hypertrophy were associated with increased odds of early-onset superimposed preeclampsia. KEY POINTS: · Concentric remodeling and concentric hypertrophy were associated with an increased risk of superimposed preeclampsia.. · Concentric hypertrophy was associated with an increased risk of delivery at less than 34 weeks.. · Two-thirds of the individuals in our study had concentric hypertrophy and concentric remodeling..


Assuntos
Hipertensão , Pré-Eclâmpsia , Nascimento Prematuro , Gravidez , Feminino , Recém-Nascido , Humanos , Estudos Retrospectivos , Remodelação Ventricular , Hipertrofia , Doença Iatrogênica
7.
Am J Perinatol ; 2022 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-36347505

RESUMO

OBJECTIVE: The American College of Obstetricians and Gynecologists suggests that an electrocardiogram is an acceptable first-line test. We sought to examine whether an electrocardiogram is a sufficient screening tool to identify echocardiogram-diagnosed left ventricular hypertrophy. We also sought to determine risk factors associated with left ventricular hypertrophy. STUDY DESIGN: This was a retrospective cohort study of pregnant individuals with chronic hypertension who delivered at 20 weeks' gestation or greater at a tertiary care center. Analyses were limited to individuals who had both electrocardiogram and echocardiogram during pregnancy. Left ventricular hypertrophy was diagnosed using the American Society of Echocardiography guidelines. Maternal demographics and electrocardiogram results were compared between individuals with left ventricular hypertrophy and those without left ventricular hypertrophy. The sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of the electrocardiogram to identify left ventricular hypertrophy were also calculated. Adjusted odds ratios (aORs) with 95% confidence intervals (95% CIs) were calculated, controlling for covariates. RESULTS: Of 172 individuals, 60 (34.9%) had left ventricular hypertrophy. The sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of the electrocardiogram to identify echocardiogram-diagnosed left ventricular hypertrophy was 18.3% (95% CI: 9.5-30.4), 91.1% (95% CI: 84.2-95.6), 2.05 (95% CI: 0.93-4.56), and 0.90 (95% CI: 0.78-1.02), respectively. Compared with individuals without left ventricular hypertrophy, those with left ventricular hypertrophy were more likely to have hypertension of 4 years' duration or longer (aOR = 4.01; 95% CI: 1.71-9.42), unknown duration of hypertension (aOR = 4.66; 95% CI: 1.28-17.04), and higher body mass index (aOR = 1.04; 95% CI: 1.01-1.07). After adjusting for covariates, left ventricular hypertrophy by electrocardiogram was not associated with actual left ventricular hypertrophy (aOR = 2.59; 95% CI: 0.94-7.10). CONCLUSION: Electrocardiogram was not a sufficient test for identifying left ventricular hypertrophy in pregnant individuals with chronic hypertension. We suggest an echocardiogram evaluation for all individuals with chronic hypertension. KEY POINTS: · The first-line test for cardiac evaluation is an electrocardiogram.. · In our cohort, the rate of left ventricular hypertrophy was 35%.. · The electrocardiogram was not sensitive to detect left ventricular hypertrophy..

8.
Med Health Care Philos ; 24(2): 227-233, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33452630

RESUMO

Time-limited trials of intensive care have arisen in response to the increasing demand for intensive care treatment for patients with a low chance of surviving their critical illness, and the clinical uncertainty inherent in intensive care decision-making. Intensive care treatment is reported by most patients to be a significantly unpleasant experience. Therefore, patients who do not survive intensive care treatment are exposed to a negative dying experience. Time-limited trials of intensive care treatment in patients with a low chance of surviving have both a small chance of benefiting this patient group and a high chance of harming them by depriving them of a good death. A 'rule of rescue' for the critically unwell does not justify time-limiting a trial of intensive care treatment and overlooks the experiential costs that intensive care patients face. Offering time-limited trials of intensive care to all patients, regardless of their chance of survival, overlooks the responsibility of resource-limited intensive care clinicians for suffering caused by their actions. A patient-specific risk-benefit analysis is vital when deciding whether to offer intensive care treatment, to ensure that time-limited trials of intensive care are not undertaken for patients who have a much higher chance of being harmed, rather than benefited by the treatment. The virtue ethics concept of human flourishing has the potential to offer additional ethical guidance to resource-limited clinicians facing these complex decisions, involving the balancing of a quantifiable survival benefit against the qualitative suffering that intensive care treatment may cause.


Assuntos
Tomada de Decisão Clínica , Cuidados Críticos , Estado Terminal/terapia , Humanos , Incerteza
10.
J Med Ethics ; 49(10): 691, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37479462
11.
Clin Orthop Relat Res ; 472(2): 497-508, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24297107

RESUMO

BACKGROUND: Concerns have been raised about the sequelae of metal-on-metal (MoM) bearings in total hip arthroplasty (THA). However, retrieval studies, which offer the best insight into the clinically relevant mechanisms of MoM wear, have followed predictable trends to date such as indicting cobalt-chromium (CoCr) metallurgy, cup design, high conformity between the head and cup, "steep cups," "microseparation," and "edge wear." QUESTIONS/PURPOSES: We wished to evaluate a set of retrieved 28-mm MoM THA for signs of (1) cup-to-stem impingement; (2) normal wear pattern and concomitant stripe damage on femoral heads that would signify adverse wear mechanics; and (3) well-defined evidence of third-body scratches on bearings that would indicate large abrasive particles had circulated the joint space. METHODS: Ten 28-mm MOM retrievals were selected on the basis that femoral stems were included. Revision surgeries at 3 to 8 years were for pain, osteolysis, and cup loosening. CoCr stems and the MoM bearings were produced by one vendor and Ti6Al4V stems by a second vendor. All but two cases had been fixed with bone cement. We looked for patterns of normal wear and impingement signs on femoral necks and cup rims. We looked for adverse wear defined as stripe damage that was visually apparent on each bearing. Wear patterns were examined microscopically to determine the nature of abrasions and signs of metal transfer. Graphical models recreated femoral neck and cup designs to precisely correlate impingement sites on femoral necks to cup positions and head stripe patterns. RESULTS: The evidence revealed that all CoCr cup liners had impinged on either anterior or posterior facets of femoral necks. Liner impingement at the most proximal neck notch occurred with the head well located and impingement at the distal notch occurred with the head rotated 5 mm out of the cup. The hip gained 20° motion by such a subluxation maneuver with this THA design. All heads had stripe wear, the basal and polar stripes coinciding with cup impingement sites. Analysis of stripe damage revealed 40 to 100-µm wide scratches created by large particles ploughing across bearing surfaces. The association of stripe wear with evidence of neck notching implicated impingement as the root cause, the outcome being the aggressive third-body wear. CONCLUSIONS: We found consistent evidence of impingement, abnormal stripe damage, and evidence of third-body abrasive wear in a small sample of one type of 28-mm MoM design. Impingement models demonstrated that 28-mm heads could lever 20° out of the liners. Although other studies continue to show good success with 28-mm MoM bearings, their use has been discontinued at La Pitie Hospital.


Assuntos
Artroplastia de Quadril/efeitos adversos , Artroplastia de Quadril/instrumentação , Impacto Femoroacetabular/etiologia , Articulação do Quadril/cirurgia , Prótese de Quadril , Próteses Articulares Metal-Metal , Acetábulo/diagnóstico por imagem , Acetábulo/cirurgia , Idoso , Remoção de Dispositivo , Feminino , Impacto Femoroacetabular/diagnóstico por imagem , Impacto Femoroacetabular/cirurgia , Cabeça do Fêmur/diagnóstico por imagem , Cabeça do Fêmur/cirurgia , Colo do Fêmur/diagnóstico por imagem , Colo do Fêmur/cirurgia , Articulação do Quadril/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Desenho de Prótese , Falha de Prótese , Radiografia , Reoperação , Fatores de Risco , Estresse Mecânico , Fatores de Tempo , Resultado do Tratamento
12.
J Bus Econ ; : 1-21, 2023 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38625357

RESUMO

A more robust, inclusive model of value creation will sharpen dominant normative theories of Corporate Social Responsibility (CSR) such as stakeholder theory and the theory of communicative/deliberative democracy. When measuring value creation, CSR theories oscillate between traditional, exchange-based approaches utilizing narrow financial metrics and value-oriented approaches embedded in prominent CSR theories. The two are often in conflict. The problem is aggravated by CSR's assumption that all firms, regardless of industry, possess the same generic responsibilities. A mining company, a sports betting service, and a medical device manufacturer are on all fours when measuring CSR success. The paper identifies a contradiction between settled normative convictions and the corporate decision making that normative CSR theories prescribe. Using the pharmaceutical industry as an example, it references the widespread conviction that during the 2019 Covid-19 pandemic some pharmaceutical companies had a responsibility to reach beyond the goal of financial optimization. It then explains why this conviction cannot be rationalized using two prominent normative theories of CSR, namely, stakeholder theory and the theory of communicative/deliberative democracy. The problem hinges on a defective model of value creation. One implication of the analysis is that healthcare companies should readjust corporate governance in order to make health a focal goal alongside that of profit. At the same time, a semiconductor firm might satisfy its CSR responsibilities by only designating profit as its focal goal. The thrust of the paper is to show why reconceiving the model of value creation can advance not only stakeholder and communicative/deliberative democracy theories, but all CSR.

13.
Postgrad Med J ; 87(1024): 83-8, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20870647

RESUMO

BACKGROUND: Wide variation in the concentrations of electrolyte infusions prepared from stock solutions has previously been reported. Layering of viscous stock electrolyte solutions in their diluent can lead to high concentrations being delivered during the infusion, resulting in potentially very serious medication errors which have caused deaths. OBJECTIVE: To determine the safest way of preparing homogenous electrolyte solutions for parenteral infusion. METHODS: The study examined how the concentration of potassium and magnesium varied during infusions after concentrated stock solutions had been diluted to 400 mmol/l with 0.9% sodium chloride. It also examined the use of syringes compared to polyvinyl chloride (PVC) bags, agitating vigorously with a 'vortex' mixer compared to inversion, and the influence of allowing the infusions to stand for 24 h before administration. The study was conducted in November 2009. Results It was found that, in general, the concentrations of potassium and magnesium solutions are less variable if they are prepared in PVC bags rather than syringes. Vigorous mixing of concentrated stock solutions with diluent and allowing preparations to stand for 24 h also improved the homogeneity of the infusions. However, even with meticulous preparation, some infusions deviated from the expected concentration by more than 10%. CONCLUSION: It is recommended that electrolyte infusions are prepared and provided by the pharmaceutical industry in prefilled syringes or bags. Given the likely cost of these products, an alternative would be to prepare infusions in pharmacy in advance, using PVC bags rather than syringes, and that they should be agitated vigorously with a 'vortex' mixer.


Assuntos
Eletrólitos/administração & dosagem , Sulfato de Magnésio/química , Preparações Farmacêuticas/química , Cloreto de Potássio/química , Embalagem de Medicamentos/métodos , Armazenamento de Medicamentos/métodos , Eletrólitos/química , Humanos , Infusões Parenterais , Erros de Medicação/prevenção & controle , Cloreto de Polivinila , Soluções/normas , Fatores de Tempo
14.
J Med Ethics ; 36(12): 816-20, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20962064

RESUMO

Discussion of real cases encountered by medical students has been advocated as a component of medical ethics education. Suggested benefits include: a focus on the actual problems that medical students confront; active learner involvement; and facilitation of an exploration of the meaning of their own values in relation to professional behaviour. However, the approach may also carry risks: students may focus too narrowly on particular clinical topics or show a preference for discussing legal problems that may appear to have clearer solutions. Teaching may therefore omit areas generally considered to be important components of the curriculum. In this paper, the authors present an analysis of the moral problems raised by medical students in response to a request to describe ethically problematic cases they had encountered during two clinical attachments, for the purpose of educational discussion at case-based seminars. We discuss the problems raised and compare the content of the cases to the UK Consensus Statement on core content of learning. The authors also describe the approaches that the students used to undertake an initial analysis of the problems raised, and consider possible implications for the development of medical ethics education.


Assuntos
Educação de Graduação em Medicina/métodos , Ética Médica/educação , Princípios Morais , Aprendizagem Baseada em Problemas , Ensino/métodos , Humanos , Estudantes de Medicina/psicologia , Reino Unido
15.
Breathe (Sheff) ; 15(1): 84-87, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30838066

RESUMO

Intensive care units with a "good" ethical environment are more likely to identify perceived excessive patient care. Patients with perceived excessive care were more likely to die and time to death was shorter in units with a "good" ethical environment. http://ow.ly/vnFP30neAZN.

16.
J Arthroplasty ; 23(7): 1090-6, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18534503

RESUMO

We present, for the first time, a detailed damage assessment of a large-diameter metal-on-metal (L-MOM) hip prosthesis to show the extent of surface damage that can occur in a patient after multiple dislocations. The patient was a man (51 years old) who dislocated 8 times and was finally revised at 27 months. Radiographically, the cup was malpositioned with 65 degrees lateral opening and 15 degrees retroversion. The retrieved cup was a 1-piece, 38-mm Co-Cr-Mo (M2a; Biomet, Warsaw, Ind) with a titanium-alloy backing. The retrieved components demonstrated all known modes of wear, including a polished wear scar, multidirectional scratching, "stripe" wear, surface contamination of titanium-alloy, front face wear, and backside wear. The clinical significance is that cup positioning remains critical regardless of whether a large diameter head is used or not.


Assuntos
Artroplastia de Quadril/efeitos adversos , Luxação do Quadril/cirurgia , Prótese de Quadril/efeitos adversos , Falha de Prótese , Luxação do Quadril/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Reoperação
20.
Orthop Clin North Am ; 36(2): 143-62, viii, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15833452

RESUMO

The second-generation, metal-on-metal (MOM) bearing for total hip replacements was launched in the 1980s, and resurfacing followed in the mid-1990s. Remaining challenges include long-term bone remodeling of the femoral resurfacing and consideration of adverse MOM wear conditions. Precise understanding of manufacturing variables such as alloy types, bearing diameters, design tolerances, and surface finish is imperative in obtaining clinical consistency and safety in the patient. This review examines femoral fixation, bone remodeling, and wear studies of MOM implants and provides a brief overview of the latest outcome and retrieval data and how these data integrate with the in vitro wear studies.


Assuntos
Fenômenos Biomecânicos , Prótese de Quadril , Metais , Desenho de Prótese , Artroplastia de Quadril/instrumentação , Artroplastia de Quadril/métodos , Materiais Revestidos Biocompatíveis , Análise de Falha de Equipamento , Segurança de Equipamentos , Humanos , Teste de Materiais , Polietilenos , Falha de Prótese , Fatores de Risco , Estresse Mecânico , Propriedades de Superfície , Titânio
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