Dislocation of the elbow: an experimental study of the ligamentous injuries.

The stability of human cadaveric elbow specimens was investigated using an experimental apparatus. Posterior dislocation of the elbow could only be produced when a combined valgus and external rotatory torque was applied to the specimen. None of the elbows were dislocated during varus and internal rotatory torque or in the extreme positions. In ten elbow specimens with an experimentally produced posterior dislocation, simultaneous rupture of the anterior part of the medial collateral ligament and the annular ligament were the most frequent findings. A lateral collateral ligament tear was only seen in two cases. Posterior elbow dislocation seems to be due to a combined valgus and external rotatory stress to the semiflexed elbow, resulting in a bilateral ligamentous injury.