[The supracondylar fracture of the humerus in children (author's transl)].

To find out the cause of posttraumatic varus and valgus deformity of the elbow a long-term follow-up examination of 183 dislocated and 20 undislocated supracondylar extension-fractures of the humerus was done. There were different methods of treatment: In most of the cases closed reduction was performed and fixation in acute angle-plaster or by percutaneous radial or radial and ulnar wires. 75% showed radiologically and 55% clinically an alteration of the carrying angle. The clear reason for this deformity was a rotation displacement, which leads in oblique fractures directly, in transverse fractures--caused by an instability--indirectly seldom to a valgus, in most of the cases to a varus deformity of the elbow. A special quotient to judge the rotation displacement is presented: the rotation failure quotient (rfq). There is no influence of lateral compression to the carrying angle. Lateral tilting is in any case a result of rotation displacement. Growth disturbance after supracondylar fractures is possible without lesion of the epiphysial plate: but as growth disturbances are seldom and their extent small, they are of no significant clinical importance. Extension displacement of the distal fragment will be spontaneously corrected in ca. 80% of all cases during the further growth. The clinical importance of posttraumatic deformities and the primary management to avoid them is discussed. The crossed percutaneous rotation-stable wire osteosynthesis is recommended as the best way of treatment. For all kinds of treatment the challenge is asked to avoid the ventral spur as a sign of rotation till consolidation of the fracture. By correct reposition in all other planes complicated measurements and reflections, as for instance the alpha-angle by Baumann, oblique or transverse fracture, pro- or supination of the forearm during fixation a.o. are unnecessary.