(iii) Elbow instability, mechanism and management

SummaryAcute dislocations of the elbow without significant fracture are classified as simple. In all cases the medial and lateral ligaments are avulsed, usually as an osteo-periosteal sleeve. The majority are stable on reduction and immediate active mobilisation is encouraged. The incidence of recurrent dislocation and instability is very low. Acute dislocations associated with significant fractures are classified as complex. The most common associated fractures are of the radial head or coronoid process, and if both fractures are present this is termed the “terrible triad”. The principle of management is reduction of the joint, anatomical fixation of the fracture fragments, with repair or reconstruction of ligaments if indicated. If the elbow remains unstable, or if fracture or fixation or ligament repair is tenuous, then the use of a hinged external fixator is recommended.The most common type of chronic instability is postero-lateral rotatory instability, which is related primarily to incompetence of the lateral ulnar collateral ligament. Conservative treatment is rarely successful and most require a reconstruction of the lateral ulnar collateral ligament with a graft. Medial instability is predominantly seen in throwing athletes with chronic stretch of the medial ligament that interferes with throwing capacity. If conservative management fails then the anterior bundle of the medial collateral ligament can be reconstructed with a tendon graft.