Einführung in die Statistik: Anwendungsorientierte Methoden zur Datenauswertung. 2., überarbeitete und erweiterte Auflage

Dieses Buch enthält eine Einführung in die Methoden der sozialwissenschaftlichen Datenanalyse. Es eignet sich als Begleittext zu einer einführenden Statistikvorlesung an Universitäten und Fachhochschulen. Ziel des Buches ist, die Grundzüge der angewandten Statistik gut verständlich und in möglichst kompakter Form zu vermitteln. Es soll die Leser und Leserinnen dazu befähigen, einfache statistische Instrumente selber anzuwenden und deren Resultate zu interpretieren. Gleichzeitig sollen die Grundlagen für das Verständnis von weiterführenden statistischen Methoden geschaffen werden. Insbesondere sollen auch Personen, die nur spärliche mathematische Vorkenntnisse besitzen und/oder kein primäres Interesse an statistischen Verfahren haben, einen einfachen Zugang zur Materie finden.

Haftfestigkeit eines mit β-Trikalziumphosphat angereichertem Knochenadhäsivs

Background: This investigation describes experimental tests of the biomechanical features of a new resorbable bone adhesive based on methacrylate-terminated oligolactides enhanced with osteoconductive β-tricalcium phosphate. Material and Methods: 51 New Zealand white rabbits were randomised to an adhesive group (n = 29) and a control group (n = 22). An extra-articular bone cylinder was taken from the proximal tibia, two stripes of adhesive were applied and the cylinders were replanted. After 10 and 21 days, 3 and 12 months tibial specimens were harvested and the cylinder pull-out test was performed with a servo-hydraulic machine. Additionally the pull-out force was evaluated with the bone-equivalent Ebazell® after 5, 10 and 360 minutes in 14 specimens each. Results: Average pull-out forces in the adhesive group were 28 N after 10 days (control: 57 N), 155 N after 21 days (216 N), 184 N after 3 months (197 N) and 205 N after 12 months (185 N). Investigations with Ebazell® showed almost identical pull-out forces after 5 min, 15 min and 360 min. Adhesive forces were as high as 125 N/cm2 of adhesive surface and more than 1200 N/g of adhesive mass. Conclusions: The adhesive investigated here has a very good primary adhesive power, compared to the literature data, achieved after only 5 minutes. Even in moist surroundings the adhesive capacity remains sufficient. The adhesive has to prove its resorptive properties in further investigations and in first line its medium-term and long-lasting biocompatibility. Furthermore, biomechanical features will have to be compared to those of conventional fixation techniques.