BACKGROUND: The decision as to whether to revise or retain a well fixed cemented acetabular component during revision of a femoral component is especially difficult; the rate of loosening of cemented acetabular components is high, whereas that of porous-coated acetabular components inserted during revision is low. However, removal of a well fixed cemented acetabular component can result in increased operative morbidity and cost and in loss of acetabular bone. Data that can be used to predict the long-term survival of retained well fixed cemented acetabular components are therefore needed. METHODS: We studied the five to thirteen-year clinical and radiographic results in a group of twenty-six consecutive patients in whom a well fixed cemented acetabular component had been retained during revision of a femoral component. Typical demographic data on the patients and information about the components were recorded, and the cemented acetabular components were graded as A through F, according to the system of Ranawat et al., at the time of the femoral revision. The average duration of follow-up was 8.4 years (range, 5.0 to 12.7 years). No patient was lost to follow-up. RESULTS: Four acetabular components (15 percent) had progressive radiolucency (at forty-eight, forty-eight, fifty-nine, and seventy-five months after the femoral revision) and were considered radiographically loose despite not being associated with symptoms. All four components were graded as either E or F at the time that they were retained during the femoral revision; radiographic loosening was significantly related to these two grades (p < 0.01). No acetabular component with a grade of A, B, C, or D loosened. The components that loosened had been in vivo for a relatively shorter, as opposed to longer, duration before the femoral revision compared with the components that did not loosen (p < 0.05). CONCLUSIONS: Retention of the well fixed cemented acetabular components was associated with good clinical results but with a 15 percent rate of loosening. Revision of a cemented acetabular component solely on the basis of the duration that it was in vivo or whether a previous revision had been done does not appear to be warranted. Our findings suggest that acetabular components with a grade of A, B, C, or D at the time of a femoral revision may be retained, as these components continued to function at the time of the five to thirteen-year follow-up in the current study. 相似文献
BACKGROUND: The verbal autopsy (VA) is used to collect information on cause-specific mortality from bereaved relatives. A cause of death may be assigned by physician review of the questionnaires, or by an algorithm. We compared the diagnostic accuracy of physician review, an expert algorithm, and data-derived algorithms. METHODS: Data were drawn from a multicentre validation study of 796 adult deaths that occurred in hospitals in Tanzania, Ethiopia, and Ghana. A 'gold standard' cause of death was assigned using hospital records and death certificates. The VA interviews were carried out by trained fieldworkers 1-21 months after the subject's death. A cause of death was assigned by physician review and an expert algorithm. Data-derived algorithms that most accurately estimated the cause-specific mortality fraction (CSMF) for each cause of death were identified using logistic regression. RESULTS: The most common causes of death were tuberculosis/AIDS (CSMF = 18.6%), malaria (CSMF = 10.7%), meningitis (CSMF = 8.3%), and cardiovascular disorders (CSMF = 8.2%). The CSMF obtained using physician review was within +/-20% of the gold standard value for 12 causes of death including the four common causes. The CSMF obtained using the expert algorithm was within +/-20% of the gold standard for eight causes of death, including tuberculosis/AIDS, malaria, and meningitis. The CSMF obtained using the data-derived algorithms was within +/-20% of the gold standard for seven causes of death, including tuberculosis/ AIDS, meningitis, and cardiovascular disorders. All three methods yielded a specificity of at least 80% for all causes of death, and a sensitivity of at least 80% for deaths due to injuries and rabies. CONCLUSIONS: For those settings where physician review is not feasible, expert and data-derived algorithms provide an alternative approach for assigning many causes of death. We recommend that the algorithms proposed herein are validated further. 相似文献
In this study an all-male population of 256 U.S. Army basic trainees and 98 armor officer basic course students were surveyed concerning extent of use, knowledge of, and factors contributing to the use of smokeless tobacco (ST). The survey was administered at a dental clinic at Fort Knox, Kentucky. The data were analyzed using the SPSS computer software program. Results showed that more than 17% of this population were either occasional or regular users of ST. Nearly 24% had tried ST and more than 9% were former users. Exactly one-half had not tried ST. A typical user was white, had started ST use at age 14, had used it for 4 years, and was most likely to use snuff or dip. Higher educational level achieved was associated with increased likelihood of ST use. Nearly 22% of college graduates used ST, whereas only 15.3% of high school graduates or those with some college were users. Knowledge about the potential health effects of ST was generally high or moderately high, except for its ability to cause hypertension. This was true for both high school and college graduates, although college graduates were somewhat more informed. Few in this population had a personal attitude of approval toward ST use, and very few perceived that either their parents or their superiors in the military approved of ST use. Perceived attitude of approval was highest from friends and peers. The principle reasons for starting ST use were use by friends and curiosity about taste and effects. Influence from public figures, such as athletes, and from advertising was minimal. Enjoyment of flavor and taste was found to be the main reason for continued ST use. Health professionals were identified by the majority of respondents as the single most important information source on ST. Relatively few (27%), however, stated that their dentist or hygienist had ever discussed ST with them. 相似文献
Background: Patients who receive a combination of a benzodiazepine and an opioid for conscious sedation are at risk for developing respiratory depression. While flumazenil effectively antagonizes the respiratory depression associated with a benzodiazepine alone, its efficacy in the presence of both a benzodiazepine and an opioid has not been established. This study was designed to determine whether flumazenil can reverse benzodiazepine-induced depression of ventilatory drive in the presence of an opioid.
Methods: Twelve healthy volunteers completed this randomized, double-blind, crossover study. Ventilatory responses to carbon dioxide and to isocapnic hypoxia were determined during four treatment phases: (1) baseline, (2) alfentanil infusion; (3) combined midazolam and alfentanil infusions, and (4) combined alfentanil, midazolam, and "study drug" (consisting of either flumazenil or flumazenil vehicle) infusions. Subjects returned 2-6 weeks later to receive the alternate study drug.
Results: Alfentanil decreased the slope of the carbon dioxide response curve from 2.14 +/- 0.40 to 1.43 +/- 0.19 l [dot] min sup -1 [dot] mmHg sup -1 (x +/- SE, P < 0.05), and decreased the minute ventilation at PET CO2 = 50 mmHg (V with dotE 50) from 19.7 +/- 1.2 to 14.8 +/- 0.9 l [dot] min sup -1 (P < 0.05). Midazolam further reduced these variables to 0.87 +/- 0.17 l [dot] min sup -1 [dot] mmHg sup -1 (P < 0.05) and 11.7 +/- 0.8 l [dot] min sup -1 (P <0.05), respectively. With addition of flumazenil, slope and V with dot sub E 50 increased to 1.47 +/- 0.37 l [dot] min sup -1 [dot] mmHg sup -1 (P < 0.05) and 16.4 +/- 2.0 l [dot] min sup -1 (P < 0.05); after placebo, the respective values of 1.02 +/- 0.19 l [dot] min sup -1 [dot] mmHg sup -1 and 12.5 +/- 1.2 l [dot] min sup -1 did not differ significantly from their values during combined alfentanil and midazolam administration. The effect of flumazenil differed significantly from that of placebo (P < 0.05). Both the slope and the displacement of the hypoxic ventilatory response, measured at PET CO2 = 46 +/- 1 mmHg, were affected similarly, with flumazenil showing a significant improvement compared to placebo. 相似文献
The European Renaissance was a time of enormous change and rapid progress in the arts, sciences, and medicine. A glimpse of wound care in the last phase of the European Renaissance is provided by the analysis of work by Wilhelm Fabry, the "father of German surgery," as provided in his book De Combustionibus ("Burns") which details his range of treatments for the burn wound, as well as his approach to the later problems of scarring and contracture. We describe some of the historic events which may have stimulated Fabry's writings, in particular, the influences passed down from the medical school of Padua which thereby advanced the cause of wound care and surgery. Finally, we briefly explore the potential of such an approach to the works of our medical forefathers. 相似文献