Summary:Supracondylar fractures of the humerus in children may be associated with difficulties in diagnosis and treatment. One of the major problems is malrotation of the distal fragment, which has to be reduced. On clinical examination, as well as radiography, the initial malrotation cannot be assessed. In the authors' experiments, they were able to show that malrotation only became visible when greater than 40° as a ventral spur on the lateral radiographic view. On the other hand, the authors also noticed a linear correlation between the degree of rotation and increasing fracture instability if the center of rotation was in the middle of the fracture. If the center of rotation was located in radial condyle, the contact surface of the fracture remained at 60° with increasing rotation. Based on these findings, the authors started to perform osteosynthesis in supracondylar fractures with a radial external fixator, which guaranteed compression on the radial column. Satisfactory reduction is checked clinically by the range of motion and the arm axis, rather than radiologically. The authors favor this method because the cosmetically disturbing cubitus varus can be avoided, and the removal of the external fixator can be performed without additional anesthesia.