Afterward he discussed these animal cases with his AO colleagues. Willenegger, who knew about the veterinary activities in Waldenburg, introduced Guggenbühl to the veterinarians, which led to his engagement as a veterinarian teacher. An animal owner and engineer In 1954, Dr Fritz Straumann (Fig 7) and his father Professor Reinhard Straumann established a private research institute in Waldenburg (near Basel) to facilitate further development, investigation, and testing of watch-spring materials and watch-spring designs that the elder Straumann had invented. The spring metal alloys were sophisticated and their production processes required close attention and metallurgical expertise. Since Fritz Straumann was very interested in all natural sciences and technology, he expanded their research beyond the watch industry into other areas as well. The concept was to invest the earnings from their patents into their research institute. In 1960 Fritz Straumann was contacted by Willenegger, who was seeking assistanceto improve the material quality of AO implants because there were problems with the corrosion and failure of plates and screws. Ortrun Pohler (Fig 8) analyzed the defect implants and found that impurities and an insufficient composition of the stainless steel were the reason for the corrosion. The breaking of the implants was caused by material fatigue where a crack propagates with time through the material under alternating bending stresses (cyclic loading). Such critical local bending stresses can be generated under the load bearing of the patient, in cases where bony defects and instability of the osteosynthesis are present. With time this phenomenon was studied in depth [46]. Straumann developed of a stainless steel with high corrosion resistance and variable mechanical properties that were particularly suited for clinical applications. This material became the model for the internationally standardized implant steel that is currently used. Straumann volunteered to help to the AO surgeons, and was able to assist in the development of various techniques to resolve clinical biomedical problems.
Fig 7 Fritz Straumann giving an address during an AO function.
Fig 8 Ortrun Pohler a scientific member of AO and an AOVET member working on a publication.
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