Anatomische und biomechanische untersuchungen zur femurmarknagelung

Zusammenfassung An einer röntgenanatomischen und morphologischen Vorstudie von insgesamt 390 Femora japanischer Individuen wird die Markraumarchitektur besonders im Bereich der physiologischen Enge, dem sogenannten Markraumisthmus, untersucht. Diesem Bezirk kommt besondere Bedeutung bei der Fixation eines intramedullären Kraftträgers zu, da nur hier ein formschlussüger Kontakt des Implantates mit der Markhöhle erwartet werden kann. Als wichtigstes Ergebnis finden die Untersucher, daß der Durchmesser des Markraumisthmus' auf dem ap-Bild um 2 mm kleiner ist als auf dem seitlichen Röntgen bild, weshalb beim Aufbohren der Markhöhle 2 mm Zugabe zum ap-Durchmesser notwendig ist, um einen kreisförmigen Querschnitt zu erzielen. Weiterhin konnte nachgewiesen werden, daß die Vorbiegung des AO-Marknagels nicht der zumindest in Japan zu erwartenden Antekurvation des Femurs entspricht. Verschiedene Versuche an 4 im Handel befindlichen Marknagelmodellen geben Aufschluß über deren elastische Eigenschaften.Um die Forderung nach möglichst großflächigem Kraftschluß zwischen Marknagel und Markraum zu erfüllen, wird ein neuer Nagel (Okayama-Nagel) vorgestellt, der verbesserte querelastische Eigenschaften aufweist and selbst noch fiber den unmittelbar zylindrisch aufgebohrten Markraumbereich hinaus in Kontakt mit der Knochenröhre tritt.

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Anatomical and biomechanical considerations for medullary nailing

Summary By using X-ray films of 390 adult femurs and 15 cadaveric femurs of Japanese origin, and by measuring successive cross-sections the authors have made morphological and statistical analyses of the shape of the femoral medullary canal. These studies suggest new dimensions for the diameter of the reamer and the amount of contact area between nail and inner cortex. Furthermore it was found that the physiological antecurvature of the femur on the lateral view does not correspond with the prebending of the AO-nail. The authors made some mechanical experiments on four types of nails which are widely used today.As a consequence of these studies, the authors developed a new elastic nail for trial (Okayama-nail). This new type of nail greatly increases the area of contact with the inner femoral cortex. Obviously this nail satisfies better all of Kuentscher's originally mentioned requirements an intramedullary nail.

     

Contribution of impaired glucose tolerance in subjects with the metabolic syndrome: Baltimore Longitudinal Study of Aging

BACKGROUND: In addition to fasting plasma glucose (FPG), we examined the contribution of the oral glucose tolerance test (OGTT) in the prevalence of subjects with the metabolic syndrome (MS). METHODS AND RESULTS: Study participants were white adults in the Baltimore Longitudinal Study of Aging who underwent a fasting 2-hour OGTT. In men between the ages of 20 to 39, 40 to 59, 60 to 79, and 80 to 95 years, the prevalence of the MS by Adult Treatment Panel (ATP) III criteria (which excludes OGTT) was 11%, 28%, 32%, and 15%, respectively; whereas in women the prevalence was 5%, 12%, 24%, and 16%, respectively. If the current ATPIII dysglycemia criteria also included a 2-hour postchallenge glucose (2hPG) of 7.8 mmol/L or higher, the prevalence of the MS increased from 25% to 33% in men and from 15% to 21% in women (P<.0001). In study participants with FPG less than 5.6 mmol/L, the prevalence of the MS increased from 16% to 23% in men and from 9% to 13% in women. In men between the ages of 20 to 39, 40 to 59, 60 to 79, and 80 to 95 years and FPG less than 5.6 mmol/L, the prevalence of the MS increased to 15%, 32%, 40%, and 29%, respectively (P<.005 for men between 40 and 95 years of age), with inclusion of an abnormal 2hPG. In women between the ages of 20 to 39, 40 to 59, 60 to 79, and 80 to 95 years and FPG less than 5.6 mmol/L, the prevalence of the MS increased to 7%, 14%, 33%, and 31%, respectively, with inclusion of an abnormal 2hPG (P<.001 for women between 60 and 95 years of age). CONCLUSION: The prevalence of the MS is significantly underestimated when the current ATPIII criteria of FPG 6.1 mmol/L or higher is the only determinant of dysglycemia.     

Awareness of disease in dementia: preliminary results in patients with mild and moderate Alzheimer's disease

OBJECTIVE: To evaluate the presence and the level of awareness of disease in mild and moderate Alzheimer's disease (AD). METHOD: Cross-sectional evaluation of patients with mild/moderate AD (n=42) assessed by Assessment of Psychosocial Impact of the Dementia Diagnosis (APSID), Mini-mental State Examination (MMSE) and Clinical Dementia Rating Scale (CDR). RESULTS: Awareness of disease and its consequences were present in 66.7% patients with mild AD (n=18). In moderate AD (n=24), 20.8% presented total awareness, 45.8% presented only awareness of cognitive symptoms. Unawareness of disease was observed in 33.3%. CONCLUSIONS: The present data show association between awareness and level of severity of disease. CDR 1 patients show a better recognition of cognitive and daily life activity symptoms, whereas CDR 2 patients recognized their cognitive symptoms but failed to appraise their severity and consequences in daily life activities.     

The precautionary principle: a dialectical reconsideration

This essay examines an overlooked element of the precautionary principle: a prudent assessment of the long-range or remote catastrophes possibly associated with technological development must include the catastrophes that may take place because of the absence of such technologies. In short, this brief essay attempts to turn the precautionary principle on its head by arguing that, (1) if the long-term survival of any life form is precarious, and if the survival of the current human population is particularly precarious, especially given contemporary urban population densities, and (2) if technological innovation and progress are necessary in order rapidly to adapt humans to meet environmental threats that would otherwise be catastrophic on a large scale (e.g., pandemics of highly lethal diseases), then (3) the development of biomedical technologies in many forms, but in particular including human germ-line genetic engineering, may be required by the precautionary principle, given the prospect of the obliteration of humans in the absence of such enhanced biotechnology. The precautionary principle thus properly understood requires an ethos that should generally support technological innovation, at least in particular areas of biotechnology.     

CD45RA+ ICAM-3+ lymphocytes in interferon-beta1b-treated and -untreated patients with relapsing-remitting multiple sclerosis

OBJECTIVES: Multiple sclerosis (MS) is believed to be an autoimmune disease of the human central nervous system mediated by autoreactive T cells. Interferon-beta1b (IFN-beta1b) has been shown to be effective in reducing disease activity defined by clinical and magnetic resonance imaging (MRI) criteria in relapsing-remitting MS (RRMS). Yet, the exact mechanisms by which these benefits are achieved remain unknown. CD45RA is a marker for naive T lymphocytes and intercellular adhesion molecule-3 (ICAM-3) is expressed on resting lymphocytes. MATERIAL AND METHODS: Forty-eight patients with RRMS, 24 of them treated with recombinant IFN-beta1b and 24 untreated, were enrolled in this prospective study over 18 months. We investigated the percentage of CD45RA+ ICAM-3+ cells within the total lymphocyte subset in the peripheral blood serially every 3 months and in CSF once at baseline. Detailed clinical examination including Expanded Disability Status Scale (EDSS) score was performed every 3 months and cranial MRI scans were assessed every 6 months. RESULTS: We found a temporary increase in the CD45RA+ ICAM-3+ lymphocyte ratio in peripheral blood of both untreated and IFN-beta1b-treated RRMS patients. Moreover, we determined a significant negative correlation (r = -0.5874; P < 0.01) between age as well as the EDSS score (r = -0.3629; P < 0.05) and the percentages of CD45RA+ ICAM-3+ lymphocytes in peripheral blood but a positive correlation between EDSS score and the CD45RA+ ICAM-3+ ratio (r = 0.3913; P < 0.05) in the CSF at baseline. CONCLUSION: CD45RA+ ICAM-3+ lymphocyte ratio in peripheral blood might indicate immunosenescence in MS. However, from our data it cannot be finally concluded whether it is also influenced by IFN-beta1b treatment.