Posterior lateral rotary instability (PLRI) of the elbow is usually the result of a lateral or radial collateral ligament injury. When this occurs, the proximal radioulnar complex can supinate or externally rotate away from the trochlea of the humerus. This will cause a subluxation of the humeroulnar and humeroradial joints (1). It is not the same as a radial head dislocation, as the annular ligament is generally intact. The mechanism of injury is often due to valgus stress, combined with axial loading and supination, which ..>>read more