Elbow dislocation is the second most common large joint dislocation in the adult population.
A dislocation with no fracture is simple whereas an accompanying fracture makes the dislocation complex. The most common fracture is a radial head fracture, although coronoid process fracture is also common. The terrible triad of the elbow is the combination of 1-3:
Elbow dislocations are common, and account for 10-25% of all elbow injuries in the adult population 1.
Most elbow dislocations are closed and are most frequently posterior (sometimes posterolateral or posteromedial) although anterior, medial, lateral and divergent dislocations are also infrequently encountered). Posterior dislocations typically occur following a fall onto an extended arm, either with hyperextension or a posterolateral rotatory mechanism 1.
In most cases plain films suffice for assessment of elbow dislocations, although CT in increasingly used to pre-operatively assess intra-articular fractures.
The dislocation is usually obvious, especially if adequate AP and lateral views are obtained, however, the challenge is in identifying associated fractures.
Although rarely required in practice, a line drawn along the anterior margin of the humerus (anterior humeral line) and one along the long axis of the radius should intersect near the centre of the capitellum 3.
In addition to reporting the presence of a dislocation a number of features should be sought and commented upon.
- dislocation direction
- posterior, posterolateral, posteromedial, lateral, medial or divergent
- associated fractures
- most frequently the radial head and coronoid process
- other fractures encountered include: lateral condyle, capitellum, olecranon 2
- wrist and shoulder may need to be imaged if there is clinical concern
Treatment and prognosis
When elbow dislocation is simple (i.e. no associated fracture) then closed reduction and a brief period (e.g. <2 weeks) of immobilisation at 90 degrees of flexion usually suffices 1,3.
Complex fracture-dislocations of the elbow require operative management, consisting reduction of the dislocation, management of the fracture and repair of surrounding damaged soft tissues (ORIF). They are far more likely to have a poor outcome, including secondary osteoarthritis, limited range of motion, instability and recurrent dislocation as well as pain 1.
Occasionally injury to the brachial artery may be seen (this is more common in open fracture-dislocations) 2.
- 1. Dines DM, Lorich D, Helfet D. Solutions for Complex Upper Extremity Trauma. Thieme Medical Pub. (2008) ISBN:1588905047. Read it at Google Books - Find it at Amazon
- 2. Marinček B, Dondelinger RF. Emergency Radiology, Imaging And Intervention. Springer Verlag. (2006) ISBN:354026227X. Read it at Google Books - Find it at Amazon
- 3. Bridgeforth G, Cherf J. Lippincott's Primary Care Musculoskeletal Radiology. Lippincott Williams & Wilkins. (2010) ISBN:0781793777. Read it at Google Books - Find it at Amazon
- elbow anatomy
- elbow radiography
- MRI of the elbow - an approach
- distal humeral fracture
- Panner disease (osteochondrosis of the capitellum)