Elbow dislocation

The second most dislocated large joint in adults. Simple dislocations have no fracture and do well with early movement. Complex dislocations come with fractures (radial head, coronoid, olecranon) and tend to be unstable; the terrible triad is the classic one.

Mechanism

Fall on the outstretched hand: axial load, valgus and supination drive the forearm posterolaterally off the humerus.

Clinical findings

• Deformity with a prominent olecranon, elbow held flexed.
• Check the brachial artery (radial pulse) and the ulnar, median and radial nerves before and after reduction.
• Look at the wrist (DRUJ, Essex–Lopresti) and the shoulder.

Imaging

• AP and lateral before and after reduction: concentric joint? CT for any fracture (radial head, coronoid).

Classification

Simple

No fracture (ligaments only).

Complex

With fractures: terrible triad, transolecranon, varus posteromedial rotational instability (anteromedial coronoid).

Direction

Posterior or posterolateral (most), anterior, medial, lateral, divergent.

Coronoid (Regan–Morrey)

I tip, II up to 50%, III more than 50% of the coronoid height.

Types shown in 3D

Simple posterior

The most common elbow dislocation (adults: second only to the shoulder). Ulna and radius go back together; no fracture. Reduce, test stability in extension, move early.

Posterolateral

The forearm rotates off the humerus around the intact medial collateral ligament (Horii circle: lateral ligament fails first, then the capsule, then the medial side).

Terrible triad

Posterior dislocation plus fractures of the radial head and the coronoid process. Very unstable: fix or replace the radial head, fix the coronoid (or its capsule), repair the lateral ligament; medial repair or hinged fixator if still unstable.

Treatment

Simple

Closed reduction (traction, correct medial/lateral shift, flex), test stability in extension; short splint then early active movement within the stable arc. Hinged brace if unstable in the last 30°.

Complex

Restore the bony stabilisers in order: coronoid (or its capsule), radial head (fixation or replacement, never excision alone in a dislocation), then the lateral ulnar collateral ligament; medial repair or hinged external fixator if still unstable.

Aftercare

Early motion is the key; avoid long immobilisation (stiffness). Heterotopic ossification prophylaxis can be considered after complex injuries.

Complications

• Stiffness (loss of extension)
• Recurrent instability
• Heterotopic ossification
• Ulnar nerve symptoms
• Brachial artery injury (rare)