RESUMEN
Electronic health records (EHRs) in the past decade have gone from a hospital-based record keeping system to integrated into almost all practices in the United States. As a result, practicing clinicians have had to adapt and change their practices to accommodate this new work flow. In this article we discuss how we got here and how to make the most of your EHR.
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Registros Electrónicos de Salud , Mano/cirugía , Ortopedia/organización & administración , Humanos , Almacenamiento y Recuperación de la Información , Sistemas de Registros Médicos ComputarizadosRESUMEN
BACKGROUND CONTEXT: Vertebral cement augmentation, including kyphoplasty, has been shown to be a successful treatment for pain relief for vertebral compression fracture (VCF). Patients can sustain additional symptomatic VCFs that may require additional surgical intervention. PURPOSE: To examine the prevalence and predictors of patients who sustain additional symptomatic VCFs that were treated with kyphoplasty. STUDY DESIGN: A retrospective review of patients who previously underwent kyphoplasty for VCFs and had additional VCFs that were treated with kyphoplasty. PATIENT SAMPLE: A total of 256 patients underwent kyphoplasty for VCFs from 2000 to 2007 at a single medical center. OUTCOME MEASURES: The outcome measure of interest was the need for an additional kyphoplasty procedure for a symptomatic VCF. METHODS: Risk factors such as age, sex, smoking status, and steroid use were assessed, as well as bisphosphonate use. Sagittal spinal alignment via Cobb angles for thoracic, thoracolumbar, and lumbar regions was assessed. RESULTS: About 22.2% of the patients had an additional symptomatic VCF that was treated with a kyphoplasty procedure. Steroid use was the only significant risk factor for predicting patients with additional symptomatic VCFs who underwent additional kyphoplasty. The average time to the second VCF was 33 days. Adjacent-level VCFs were most common in the thoracic and thoracolumbar spine. Bisphosphonate use was not shown to be protective of preventing additional VCFs during this follow-up period. CONCLUSION: This is the first single-center review of a large cohort of patients who underwent additional-level kyphoplasty for symptomatic VCFs after an index kyphoplasty procedure. Our results suggest that patients with a VCF who use chronic oral steroids should be carefully monitored for the presence of additional symptomatic VCFs that may need surgical intervention. Patients with prior thoracic VCFs who have additional back pain should be reevaluated for a possible adjacent-level fracture.
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Fracturas por Compresión/epidemiología , Fracturas por Compresión/cirugía , Cifoplastia , Fracturas de la Columna Vertebral/epidemiología , Fracturas de la Columna Vertebral/cirugía , Administración Oral , Corticoesteroides/administración & dosificación , Anciano , Femenino , Humanos , Masculino , Prevalencia , Estudios Retrospectivos , Factores de RiesgoRESUMEN
Callus formation occurs in the presence of secondary bone healing and has relevance to the fracture's mechanical environment. An objective image processing algorithm was developed to standardize the quantitative measurement of periosteal callus area in plain radiographs of long bone fractures. Algorithm accuracy and sensitivity were evaluated using surrogate models. For algorithm validation, callus formation on clinical radiographs was measured manually by orthopaedic surgeons and compared to non-clinicians using the algorithm. The algorithm measured the projected area of surrogate calluses with less than 5% error. However, error will increase when analyzing very small areas of callus and when using radiographs with low image resolution (i.e. 100 pixels per inch). The callus size extracted by the algorithm correlated well to the callus size outlined by the surgeons (R2=0.94, p<0.001). Furthermore, compared to clinician results, the algorithm yielded results with five times less inter-observer variance. This computational technique provides a reliable and efficient method to quantify secondary bone healing response.
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Algoritmos , Callo Óseo/diagnóstico por imagen , Fracturas del Fémur/diagnóstico por imagen , Intensificación de Imagen Radiográfica/métodos , Interpretación de Imagen Radiográfica Asistida por Computador/métodos , Curación de Fractura , Humanos , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
BACKGROUND: Locking plates transmit load through fixed-angle locking screws instead of relying on plate-to-bone compression. Therefore, locking screws may induce higher stress at the screw-bone interface than that seen with conventional nonlocked plating. This study investigated whether locked plating in osteoporotic diaphyseal bone causes a greater periprosthetic fracture risk than conventional plating because of stress concentrations at the plate end. It further investigated the effect of replacing the locked end screw with a conventional screw on the strength of the fixation construct. METHODS: Three different bridge-plate constructs were applied to a validated surrogate of the osteoporotic femoral diaphysis. Constructs were tested dynamically to failure in bending, torsion, and axial loading to determine failure loads and failure modes. A locked plating construct was compared with a nonlocked conventional plating construct. Subsequently, the outermost locking screw in locked plating constructs was replaced with a conventional screw to reduce stress concentrations at the plate end. RESULTS: Compared with the conventional plating construct, the locked plating construct was 22% weaker in bending (p = 0.013), comparably strong in torsion (p = 0.05), and 15% stronger in axial compression (p = 0.017). Substituting the locked end screw with a conventional screw increased the construct strength by 40% in bending (p = 0.001) but had no significant effect on construct strength under torsion (p = 0.22) and compressive loading (p = 0.53) compared with the locked plating construct. Under bending, all constructs failed by periprosthetic fracture. CONCLUSIONS: Under bending loads, the focused load transfer of locking plates through fixed-angle screws can increase the periprosthetic fracture risk in the osteoporotic diaphysis compared with conventional plates. Replacing the outermost locking screw with a conventional screw reduced the stress concentration at the plate end and significantly increased the bending strength of the plating construct compared with an all-locked construct (p = 0.001).
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Placas Óseas , Fracturas del Fémur/cirugía , Tornillos Óseos , Diseño de Equipo , Análisis de Falla de Equipo , Fijación de Fractura/instrumentación , Humanos , Ensayo de Materiales , Osteoporosis/complicaciones , Estrés MecánicoRESUMEN
BACKGROUND: Periodic clinical and radiographic evaluation is commonly recommended by orthopaedic surgeons to monitor patients following total joint arthroplasty, yet the compliance with and efficacy of patient follow-up protocols have not been well defined. The purpose of this study was to evaluate patient compliance with early clinical follow-up after total hip arthroplasty or total knee arthroplasty. METHODS: We performed a retrospective review of clinical follow-up compliance for 776 patients who had undergone a total joint arthroplasty in the lower extremity. This cohort included 505 total hip arthroplasties (372 primary and 133 revision procedures) and 271 total knee arthroplasties (195 primary and seventy-six revision procedures). The patients were given one-time verbal instructions by the treating surgeon at the three-month postoperative visit to return for the one-year follow-up evaluation. At the one-year follow-up evaluation, those who returned were once again verbally instructed to return a year later. Demographic factors, functional hip and knee scores, and follow-up compliance at one and two years after surgery were assessed. RESULTS: Patient compliance with clinical follow-up after all arthroplasties was 61% at one year and 36% at two years. With use of a multivariate model for patients who had total hip arthroplasty, the analyses showed that a revision hip procedure (p = 0.006), younger patient age (p = 0.04), and a higher preoperative Harris hip score for gait (p = 0.04) were associated with follow-up compliance at two years. Of the factors analyzed for patients who had total knee arthroplasty, only nonwhite race (p = 0.03) was found to be a positive predictor of follow-up compliance at the two-year follow-up interval. CONCLUSIONS: Patient compliance with clinical follow-up after total joint arthroplasty in response to a verbal request made by the surgeon once at three months and once at one year postoperatively was poor in this series. These data indicate that this method (one-time verbal instruction) is insufficient to ensure compliance for follow-up after total joint arthroplasty.
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Artroplastia de Reemplazo de Cadera , Artroplastia de Reemplazo de Rodilla , Continuidad de la Atención al Paciente , Cooperación del Paciente , Anciano , Femenino , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/diagnóstico , Sistema de Registros , Reoperación , Estudios Retrospectivos , Factores de RiesgoRESUMEN
BACKGROUND: Microwave ablation has been used to replace the traditional incisions used in the surgical treatment of atrial fibrillation. However, dose-response curves have not been established in surgically relevant models. The purpose of this study was to develop dose-response curves for the Flex 10 (Guidant, Inc) microwave device in both the acute cardioplegia-arrested heart and on the beating heart. METHODS: Twelve domestic pigs (40 to 45 kg) were subjected to microwave ablation in either the arrested (n = 6) or beating heart (n = 6). The cardioplegia-arrested heart was maintained at 10 degrees to 15 degrees C while six atrial endocardial and seven right ventricular epicardial lesions were created in each animal. On the beating heart, six right atrial and seven ventricular epicardial lesions were created. Ablations were performed for 15, 30, 45, 60, 90, 120, and 150 seconds (65 W, 2.45 GHz). The tissue was stained with 2,3,5-triphenyl-tetrazolium chloride, and sectioned at 5-mm intervals. Lesion depth and width were determined from digital micrographs. RESULTS: Mean atrial wall thickness was 2.8 mm (range, 1 to 8 mm). In the arrested heart, 94% of atrial lesions were transmural at 45 seconds and 100% were transmural at 90 seconds. In the beating heart, only 20% of atrial lesions were transmural despite prolonged ablation times (90 seconds). Ventricular lesion width and depth increased with duration of application, and were similar on the arrested and beating hearts. CONCLUSIONS: Microwave ablation produces linear dose-response curves. Transmural lesions can be reliably produced on the arrested heart, but not consistently on the beating heart.
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Fibrilación Atrial/cirugía , Electrocoagulación/métodos , Microondas/uso terapéutico , Enfermedad Aguda , Animales , Modelos Animales de Enfermedad , Relación Dosis-Respuesta en la Radiación , Electrocoagulación/instrumentación , Endocardio/patología , Endocardio/cirugía , Paro Cardíaco Inducido , Atrios Cardíacos/patología , Atrios Cardíacos/cirugía , Ventrículos Cardíacos/patología , Ventrículos Cardíacos/cirugía , Contracción Miocárdica , Pericardio/patología , Pericardio/cirugía , Sus scrofa , Factores de TiempoRESUMEN
BACKGROUND: Hyperkalemic cardioplegia (Plegisol) has been shown to result in myocyte swelling and reduced contractility. We have demonstrated the elimination of these detrimental effects by the addition of an adenosine triphosphate-sensitive K+ (KATP) channel opener. To examine whether the mitochondrial or sarcolemmal KATP channel might be involved, volume and contractility in isolated myocytes from wild-type mice and mice lacking the sarcolemmal KATP channel (Kir6.2-/-) were evaluated. METHODS: Myocytes were perfused for 20 minutes each with control 37 degrees C Tyrode's solution, test solution, and then control solution. Test solutions were (n = 10 per group) either 9 degrees C Plegisol or 9 degrees C Plegisol with 100 micromol/L of diazoxide, a putative mitochondrial-specific KATP channel opener. Cell volume and contractility were measured by digital video microscopy at baseline and during the test solution and reexposure periods. RESULTS: Myocytes from wild-type mice, perfused with 9 degrees C Plegisol, demonstrated significant cell swelling (11.2% +/- 0.4%; p < 0.01) and diminished contractility (32.5% +/- 9.6% reduction in percent shortening, 47.2% +/- 10.1% reduction in peak velocity of shortening, and 52.0% +/- 8.8% reduction in peak velocity of relengthening; p < 0.05) versus baseline. Cell swelling and diminished contractility were significantly reduced by the addition of diazoxide. In Kir6.2-/- myocytes, Plegisol caused a greatly reduced level of cell swelling (3.2% +/- 0.1%; p < 0.01), and this was unaffected by diazoxide. Contractility was unchanged in Kir6.2-/- myocytes after Plegisol. CONCLUSIONS: The sarcolemmal KATP channel appears necessary for exaggerated cell swelling and reduced contractility to occur after hyperkalemic cardioplegia in mouse myocytes.
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Soluciones Cardiopléjicas/toxicidad , Diazóxido/farmacología , Miocitos Cardíacos/efectos de los fármacos , Canales de Potasio de Rectificación Interna/fisiología , Potasio/toxicidad , Sarcolema/enzimología , Animales , Bicarbonatos/farmacología , Bicarbonatos/toxicidad , Cloruro de Calcio/farmacología , Cloruro de Calcio/toxicidad , Soluciones Cardiopléjicas/química , Soluciones Cardiopléjicas/farmacología , Tamaño de la Célula/efectos de los fármacos , Femenino , Ventrículos Cardíacos/citología , Técnicas In Vitro , Soluciones Isotónicas/farmacología , Magnesio/farmacología , Magnesio/toxicidad , Masculino , Ratones , Ratones Noqueados , Contracción Miocárdica/efectos de los fármacos , Miocitos Cardíacos/enzimología , Miocitos Cardíacos/ultraestructura , Presión Osmótica , Potasio/farmacología , Canales de Potasio de Rectificación Interna/deficiencia , Canales de Potasio de Rectificación Interna/genética , Cloruro de Potasio/farmacología , Cloruro de Potasio/toxicidad , Cloruro de Sodio/farmacología , Cloruro de Sodio/toxicidadRESUMEN
BACKGROUND: The critical mass hypothesis for atrial fibrillation (AF) was proposed in 1914. There has never been a systematic investigation defining the relationship between tissue geometry and AF. The purpose of this study was to determine the association among the probability of maintaining AF and the width, area, weight, effective refractory period (ERP), and wavelength in atrial tissue. METHODS AND RESULTS: Isolated canine atria (n=20) were perfused with Krebs-Henseleit solution. Baseline ERPs were obtained with and without acetylcholine (10E-3.5 mol/L) using single extra-stimulus pacing while unipolar electrograms were recorded from 250 sites. The tissue was then partitioned using bipolar radiofrequency ablation, and the ERPs were measured again with and without acetylcholine. Any section of tissue that maintained AF was divided until the arrhythmia was no longer inducible. ERPs and conduction velocities were measured in all of the sections after each ablation, and the wavelengths were calculated. The probability of AF was found to be correlated with increasing tissue areas, widths, and weights (P<0.001). The probability of AF was significantly associated with the length of the ERP and the wavelength (P<0.001). With shorter ERPs and shorter wavelengths, there was an increased probability of sustained AF. CONCLUSIONS: The probability of sustained AF was significantly associated with increasing tissue area, width, and weight and decreasing ERPs and wavelengths. These data may lead to a better understanding of the mechanism of AF and, thus, help to design more-effective interventional procedures in the future.
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Fibrilación Atrial/fisiopatología , Atrios Cardíacos/patología , Contracción Miocárdica/fisiología , Periodo Refractario Electrofisiológico , Acetilcolina/farmacología , Animales , Fibrilación Atrial/patología , Fibrilación Atrial/cirugía , Ablación por Catéter , Perros , Electrocardiografía , Atrios Cardíacos/efectos de los fármacos , Atrios Cardíacos/cirugía , Técnicas In Vitro , Modelos Cardiovasculares , Tamaño de los ÓrganosRESUMEN
INTRODUCTION: Microwave ablation has been used clinically for the surgical treatment of atrial fibrillation, particularly during valve procedures. However, dose- response curves have not been established for this surgical environment. The purpose of this study was to examine dosimetry curves for the Flex 4 and Flex 10 microwave devices in an acute cardioplegia-arrested porcine model. METHODS: Twelve domestic pigs (40-45 kg) were acutely subjected to Flex 4 (n = 6) and Flex 10 (n = 6) ablations. On a cardioplegically arrested heart maintained at 10-15(o)C, six endocardial atrial and seven epicardial ventricular lesions were created in each animal. Ablations were performed for 15 s, 30 s, 45 s, 60 s, 90 s, 120 s, and 150 s (65 W, 2.45 GHz). The tissue was stained with 2,3,5-triphenyl-tetrazolium chloride and lesions were sectioned at 5 mm intervals. Lesion depth and width were determined from digital photomicrographs of each lesion (resolution +/- .03 mm). RESULTS: Average atrial thickness was 2.88 +/- .4 mm (range 1.0 to 8.0 mm). 94% of ablated atrial sections created by the FLEX 4 (n = 16) and the FLEX 10 (n = 16) were transmural at 45 seconds. 100% of atrial sections were transmural at 90 seconds with the FLEX 10 (n = 14) and at 60 seconds with the Flex 4 device (n = 15). Lesion width and depth increased with duration of application. CONCLUSION: Both devices were capable of producing transmural lesions on the cardioplegically arrested heart at 65 W. These curves will allow surgeons to ensure transmural ablation by tailoring energy delivery to the specific atrial geometry.
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Paro Cardíaco Inducido , Paro Cardíaco/etiología , Paro Cardíaco/radioterapia , Microondas/uso terapéutico , Animales , Relación Dosis-Respuesta en la Radiación , Diseño de Equipo , Atrios Cardíacos/efectos de la radiación , Radioterapia/instrumentación , PorcinosRESUMEN
BACKGROUND: The Cox-Maze procedure is the gold standard for the surgical treatment of atrial fibrillation with proven long-term efficacy. However, its application has been limited by its complexity and significant morbidity. The purpose of this study was to test the feasibility and safety of performing the Cox-Maze procedure using bipolar radiofrequency ablation on the beating heart without cardiopulmonary bypass. METHODS: After median sternotomy, 6 Hanford mini-pigs underwent a modified Cox-Maze procedure using bipolar radiofrequency energy. The animals survived for 30 days. Atrial function, coronary artery, pulmonary vein anatomy, and valve function were assessed by magnetic resonance imaging. At reoperation, pacing documented electrical isolation of the pulmonary veins. Induction of atrial fibrillation was attempted by burst pacing with cholinergic stimulation. Histologic assessment was performed after sacrifice. RESULTS: There were no perioperative mortalities or neurologic events. At 30 days, atrial fibrillation was unable to be induced, and pulmonary vein isolation was confirmed by pacing. Magnetic resonance imaging assessment revealed no coronary artery or pulmonary vein stenoses. Although atrial ejection fraction decreased slightly from 0.344 +/- 0.0114 to 0.300 +/- 0.055 (p = 0.18), atrial contractility was preserved in every animal. Histologic assessment showed all lesions to be transmural, and there were no significant stenoses of the coronary vessels or injuries to the valves. CONCLUSIONS: Virtually all of the lesions of the Cox-Maze procedure can be performed without cardiopulmonary bypass using bipolar radiofrequency energy. There were no late stenoses of the pulmonary veins. Clinical trials of this new technology on the beating heart are warranted.