The evolution of AO/ASIF views on fracture treatment, which has occured within last 50 years, is described in the present paper. In that time AO principles has been changed from mechanical approach to fracture care to methods considering first of all the biological aspects of injury. It has been manifested in invention of new implants of lower affect on bone tissue and emphasizing of soft tissue and atraumatic surgery technique importance. Described changes were based on careful analysis of obtained treatment results, creation of trauma centers collecting the large numbers of trauma patients and on broad experimental researches on bone biology, it's vascularisation and healing as well as on bone pathology.