Herstellung und Festigkeitsuntersuchungen nach DIN-Norm von Osteosyntheseschrauben aus boviner Kompakta (CB-Schrauben)

Schrauben sind das am häufigsten verwendete Implantat bei der Osteosynthese. Meist haben sie nur eine temporäre Funktion und werden in einer Zweitoperation wieder entfernt. Biodegradable Schrauben ersparen die Metallentfernung und ermöglichen eine allmähliche Lastübertragung auf den heilenden Knoche...

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Bibliographic Details
Main Author: Meuschke, Felix
Contributors: Gotzen, L. (Prof. Dr.), Schnabel, M. (Prof. Dr.) (Thesis advisor)
Format: Doctoral Thesis
Language:German
Published: Philipps-Universität Marburg 2007
Subjects:
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Screws are the most commonly used implant for osteosynthesis. Mostly they have a temporary function and are removed in a secondary operation. Biodegradable screws make the removal of the metal unnecessary and facilitate a gradual transfer of the weight to the healing bone. Screws made of resorbable polymers have been in use since the 1960’s, but foreign body reactions and a long time of degradation are observed. The use of screws made of bone for osteosynthesis is being described since 1918. However, the stability of screws made of bovine compact bone is characterised in literature only inadequately. The first part of the dissertation consisted of the production of 200 CB-Screws (CB= Compact Bone) with different thread-diameters and –lengths made of cortical middle-backfoot-bone from bulls. The screws were then treated with Acetone and autoclaved 20 min. at 121°C. The second phase comprised the development and production of a torsion-, tension and shear test, in order to make stability tests according to DIN-Norm. The last step was then to determine torque, tension and shear failure as well as tension and shear stability. As a result the tests imply, that CB-Screws possess the mechanical strength to serve as tension screws to stabilize low-stress fractures. When inserting the CB-Screws a torque wrench is recommended.