Variabilidad interobservador en las mediciones de radiografías de prótesis totales de rodilla / Inter-observer variability in measurements of X-rays of total knee replacements

Objetivo. Valorar la reproducibilidad de las medidas consideradas estándar por la Knee Society en la valoración de una prótesis total de rodilla. Material y método. Tres observadores midieron en veinte rodillas protésicas los ángulos alfa, beta femorotibial, sagital femoral, sagital tibial y de lateralidad patelar. Estas mediciones se obtuvieron de radiografías simples en las proyecciones anteroposterior, lateral y axial de rótula a 30°. Se calculó el coeficiente de correlación intraclase (ICC) para valorar la variabilidad interobservador de estas mediciones. Resultados. Todos los ángulos estudiados tienen una reproducibilidad excelente (ICC > 0,75), excepto el ángulo alfa y sagital tibial, que se encuentran de todas formas muy cercanos a este límite (0,74 y 0,76, respectivamente). Conclusiones. Las mediciones sobre radiografías de prótesis de rodilla antes descritas son similares entre distintos observadores con una reproducibilidad buena o muy buena, por lo que se podrían utilizar con objeto de unificar resultados en los distintos trabajos de los diferentes investigadores. Además se realizan sobre radiografías simples en proyecciones comunes en los estudios realizados en las rodillas, y por tanto son asequibles para la mayoría de los centros sanitarios, a diferencia de otros medios como la tomografía axial computarizada (TAC) o la resonancia magnética nuclear (RMN). La Knee Society considera como estándar las líneas radiolucentes en la valoración de las prótesis totales de rodilla que, al haber sido demostrada en otros estudios la no reproducibilidad, se han desestimado en el presente trabajo

Aim. To determine how reproducible Knee Society standard measurements are when evaluating total knee replacement. Materials and methods. In 20 cases of knee replacement three observers measured different angles: alpha angle, beta tibiofemoral angle, sagittal femoral angle, sagittal tibial angle and lateral patellar angle. These measurements were done on simple X-rays in the following projections: anteroposterior (AP), lateral and axial of the patella at 30°. The intra-class correlation coefficient (ICC) was calculated to assess inter-observer variability of these measurements. Results. All the angles studied have excellent reproducibility (ICC > 0.75) except for the alpha angle and the sagittal tibial angle, although these are very close to the above mentioned coefficient (0.74 and 0.76, respectively). Conclusions. measurements of knee prosthesis performed on simple X-rays are similar when taken by different observers with a degree of reproducibility of good to very good. Therefore, these measurements can be used with the aim of unifying the results of work carried out by different researchers. Moreover, they are performed on plain knee X-rays taken during ordinary knee studies and can therefore be obtained by most health centres, which is not the case for CAT scans or MRIs. The Knee Society considers the radiolucent lines as standards for assessment of total knee replacement prostheses, but as other studies have demonstrated that they are not reproducible they have not been considered in this study

[Effect of obesity on the morphology of the left ventricle]. / Influencia de la obesidad sobre la morfología del ventrículo izquierdo.

BACKGROUND: To analyze the relationship between obesity in its different degrees and the left ventricle morphology. PATIENTS AND METHODS: M-mode echocardiography was used to estimate the mass, wall thickness and internal dimension of left ventricle in 48 obese women with different degrees of obesity, defined according to the body mass index. 25 women with normal weight were used as controls. RESULTS: The body mass index was correlated with left ventricular mass, as well as with both the wall thickness of the left ventricle and its diastolic internal dimension. The abnormalities in the heart morphology increased according to the obesity degree, ranging from a 59% in the lesser obesity group up to a 100% in the more obese women. The incidence of the left ventricular hypertrophy determined by echocardiography also increased along with the body mass index, ranging from a 29% in the lesser degree of obesity women up to an 82% in the patients with a body mass index > 35 kg/m2. CONCLUSIONS: Obesity, even in its lowest degrees, shows frequent alterations in the heart morphology. This is related with a left ventricular mass increase and a higher incidence of the left ventricular hypertrophy. The left ventricular mass increase is due to an increase in the left ventricular walls thickness and also to a dilatation of its cavity.