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Prevalence of osteoarthritis (OA) is less common in the ankle compared to other joints; however, deformation brought on by degeneration causes pain, loss of function, and overall decreased quality of life. Current surgical interventions for end-stage ankle OA are not as reliable as surgical treatments for other joints. Ankle arthroplasty currently has high failure rates, and there are lack of substantial data from long-term outcome studies. By understanding the morphometric changes that occur during the different stages of OA, we are able to identify early signs of the disease with the intention to apply treatment earlier in order to preclude the need for end-stage surgical intervention. The goals of this study are to assess morphometric parameters of the talus as it relates to the progression of OA and to evaluate the effect of gender and anatomical side. A retrospective study was performed where data from sixty-eight CT scans were obtained from two study groups, one with OA and one without. The subjects were segmented, standardized, and normalized in order to study several 3D parameters of the talus, including height, radius of curvature, and volume. Results showed that talar morphometry is influenced by gender and that geometric changes are a function of OA progression. The lateral radii of subjects with OA was significantly larger than those of normal ankles (p<0.0001), and there is evidence of inherent changes between KL grades (p=0.0003). Identifying morphometric changes of the talus at each stage of OA can inherently contribute to better understanding the degenerative process. Assessing specific characteristics at earlier stages of the diseases may help clinicians to diagnose more accurately and to better provide treatment.

Zum kraft- und formschlüssigen Fügen von dünnwandigen, filigranen Betonfertigteilen eignen sich besonders kontinuierliche, flächige Verbindungen, die durch Verkleben erzielt werden können. Im Rahmen dieses Vorhabens sollten möglichst einfach zu handhabende Klebverbindungen für Platten- und Scheibenbauteile konstruiert und optimiert werden. Die Verbindungen sollten so ausgelegt werden, dass sie sowohl Beanspruchungen aus einzelnen Schnittgrößen als auch aus Schnittgrößenkombinationen übertragen können. Die einzelnen Parameter, die dabei untersucht werden sollten, sind im Wesentlichen die Klebefugengeometrie sowie die Oberflächenbeschaffenheit und Bewehrung der zu verklebenden Bauteile. Als Klebstoff sollte in erster Linie ein zementgebundener Hochleistungsmörtel, eingesetzt werden. Das Optimieren der Klebefugengeometrie und der Bewehrung in der Nähe der Fuge erfolgte mit Hilfe eines mathematisch fundierten Shape- und Topologie-Optimierungsverfahrens, wobei die Fugengeometrie sowie das Interface zwischen Beton und Bewehrung mit Level-Set-Funktionen beschrieben wurden. Dieses Verfahren nutzt den topologischen Gradienten als Maß für die Sensitivität der Zielfunktion bzgl. der Größe einer Pore oder eines Risses in einem gegebenen Punkt im Bauteil [1]. Auf der Grundlage von Kleinteilversuchen wurden Bruchkriterien entwickelt, die die Festigkeit der Klebefuge sowohl für eine kombinierte Schub-Druck- als auch für eine Schub-Zugbeanspruchung beschreiben. Basierend auf den gewonnenen Erkenntnissen wurden weiterhin Entscheidungshilfen zur Fugengestaltung sowie ein ingenieurmäßiger Bemessungsansatz erarbeitet. [Aus: Kurzzusammenfassung] / Continuous two-dimensional connections, which are achieved by gluing are particularly suitable for the force-locking and form-fit joining of thin-walled, filigree precast concrete elements. Within the framework of this project, easy-to-handle adhesive joints for plate and plane components can be designed and optimized. The connections should be designed in such a way that they can withstand both stresses from individual internal forces as well as from combinations of internal forces. In essence, the individual parameters that should be investigated are the geometry of the bonding joint as well as the surface condition and reinforcement of the components to be bonded. A cementitious high-performance mortar should primarily be used as adhesive. The optimization of the adhesive joint geometry and the reinforcement close to the joint was carried out by means of a mathematically founded shape and topology optimization method, whereby the joint geometry as well as the interface between concrete and reinforcement were described with level set functions. This method uses the topological gradient as a measure of the sensitivity of the objective function to the size of a pore or crack at a given point in the structural member [1]. On the basis of small part tests, fracture criteria were developed which describe the strength of the adhesive joint both for a combined shear-compressive and a shear-tensile load. Based on the knowledge gained, decision supports for joint design and an engineering design approach were also developed. [Off: Summary]