Posterolateral Rotatory Instability of the Elbow

Posterolateral rotatory instability of the elbow (PLRI) is a form of ulnohumeral instability caused by injury or abnormality of the lateral collateral ligament of the elbow, and manifests as posterior dislocation of the radial head relative to the capitellum. PLRI forms part of a spectrum of increasing elbow instability. Isolated PLRI may be acute as a result of traumatic dislocation or fracture dislocation, chronic following an initial trauma or related to hyperlaxity, cubitus varus or iatrogenic injury. 

Diagnosis of PLRI requires a high index of clinical suspicion and an understanding of the pathoanatomy of elbow instability. Treatment consists of identification of the contributing bony and soft tissue elements to PLRI and appropriate repair or reconstruction of these structures. 

This chapter addresses the pathoanatomy, diagnosis and management of acute and chronic PLRI with an emphasis on the consideration of PLRI as part of a spectrum of global elbow instability.