Anteriorly displaced supracondylar fractures of the humerus are caused by lateral rotation injury and posteriorly displaced by medial rotation injury: a new hypothesis.

During the last 20 years, the author has treated 1120 cases of supracondylar fractures of the humerus in children and has proposed a new hypothesis. In supracondylar fractures of the humerus it is the rotational force at the time of the injury, which determines the antero-posterior displacement. Medial rotation injury because of an anterior fall on an outstretched hand with forearm pronated is associated with posterior displacement and lateral rotation injury because a posterior fall on the outstretched hand with supinated forearm is associated with anterior displacement.