RESUMEN
The purposes of this study were to determine: (1) whether an observer's perception of the correct anatomical alignment of the head changes with time, and (2) whether different observers agree on the correct anatomical alignment. To determine whether the perception of the correct anatomical alignment changes with time (intra-observer comparison), a group of 30 observers were asked to orient, into anatomical alignment, the three-dimensional (3D) head photograph of a normal man, on two separate occasions. To determine whether different observers agree on the correct anatomical alignment (inter-observer comparison), the observed orientations were compared. The results of intra-observer comparisons showed substantial variability between the first and second anatomical alignments. Bland-Altman coefficients of repeatability for pitch, yaw, and roll, were 6.9°, 4.4°, and 2.4°, respectively. The results of inter-observer comparisons showed that the agreement for roll was good (sample variance 0.4, standard deviation (SD) 0.7°), the agreement for yaw was moderate (sample variance 2.0, SD 1.4°), and the agreement for pitch was poor (sample variance 15.5, SD 3.9°). In conclusion, the perception of correct anatomical alignment changes considerably with time. Different observers disagree on the correct anatomical alignment. Agreement among multiple observers was bad for pitch, moderate for yaw, and good for roll.
Asunto(s)
Cabeza/anatomía & histología , Humanos , Imagenología Tridimensional , Masculino , Variaciones Dependientes del Observador , Posicionamiento del Paciente , Fotograbar , Reproducibilidad de los ResultadosRESUMEN
The collagen architecture in normal, aging, and osteoarthritic articular cartilage was studied optically using a new silver staining technique based on specimens from 50 autopsy cases, four amputated limbs, and six osteoarthritic knees. In the normal articular cartilage, the collagen fibrils in the superficial zone were compactly arranged into layers of decussating flat ribbons mostly parallel to the artificial split lines. The fibrils showed a tendency to condense into vertical arcade columns undergirded by tangential bundles in the intermediate zone. In the deep zone, the fibrils formed a random meshwork with a slight preponderance of vertical fibrils in the perilacunar region. Three types of early degradative lesions involving the collagen network were identified. Type I lesions consisted of focal superficial disruptions related to age and friction. Type II lesions consisted of focal disruptions of tangential fibrils in the intermediate zone leading to cyst formation, probably representing a form of local stress failure. Type III lesions were found in the patella and consisted of marked swelling of the superficial zone, the cause of which was unknown. Lesions of varying severity were seen within each of the three types; the morphological changes of the more severe lesions overlapped with those of clinically overt osteoarthritis.
Asunto(s)
Cartílago Articular/ultraestructura , Colágeno/ultraestructura , Osteoartritis/patología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Envejecimiento/patología , Humanos , Microscopía Electrónica , Persona de Mediana EdadRESUMEN
Antibiotics given perioperatively are thought to decrease the occurrence of postoperative wound infection. The duration of treatment for hip fracture surgery is empirical. This randomized, double-blind, single-hospital clinical study was carried out to assess the effect of both antibiotic use and duration of use on wound infections in hip fracture surgery. Wound infection rates in three groups of patients were compared: those who received four doses of cefazolin (108 patients), those who received one dose of cefazolin and three doses of placebo (83 patients) and those who received four placebo doses (121 patients). Results showed an infection rate of 1.6% for the four-dose group, 2.4% for the one-dose group and 3.7% for the placebo group. These differences were not statistically significant, even when both treatment groups were combined and compared with the placebo group. The authors conclude that until more patients are added, empirical use of antibiotics should be continued in patients who undergo hip fracture surgery.