[Theoretical principles and biomechanics of external fixator osteosynthesis].

It has become necessary to improve the technical properties of external fixation. To achieve this we tested different constructions based on the tubular system of ASIF for external fixation. By axial centric and eccentric loading we investigated the displacement of the bone fragments, the degree of bending of Steinmann nails and the pressure transmitted to the tubes. According to the investigations, certain basic rules and technical aspects have to be considered in external fixation. Knowledge of the pathophysiology of the damaged area is also a precondition in using this operative technique. Classification of different methods of osteosynthesis and their indications is proposed.