Activity of AO group from the beginning of its formation till now is presented in that paper. From 1958, in which Müller presented three main principles of osteosynthesis, which brought world wide revolution in therapy of injuries of muscoskeletal system, opinions on therapy of fractures changed. Evaluation of these opinions was investigated from absolute stability of fractures with union of fractured bones without formation of callus, which was considered as phenomenon of healing, and which method was promoted for years till relative stability. Causes that led to change of these opinions were presented, from completely mechanical to biological attitude. These opinions were accompanied by changes of therapy methods from anatomical reduction of fractures and absolute stability through biological connections till microinvasive unions of fractured bones. Changes that occurred in applied implants were also investigated, from simple DCP plate, LC-DCP to LCP plate, plates distant from bone with screws blocking in the plate. Also visible changes took place in intramarrow nails from normal nails through blocked to nails of new generation. That paper presented in what way AO philosophy influenced on change of attitude to therapy of fractures in Poland, as well as participation of Polish idea in that philosophy. Actual state of polish traumatology was taken into consideration as well as trends in training of Polish orthopaedists and cooperation of Polish orthopaedic surgeons with AO group.