AKT · Musculoskeletal/Fractures, trauma & soft tissuelow yield

Joint dislocation & subluxation

Complete (dislocation) or partial (subluxation) loss of joint congruity

Overview

Loss of the normal articulation of a joint — complete (dislocation) or partial (subluxation). The shoulder is the commonest (usually anterior); other key ones are the patella, hip (including prosthetic), and the elbow. The priorities are prompt reduction, documenting neurovascular status before and after, and post-reduction imaging.

Recognise

Pain, deformity, loss of movement; the limb held in a characteristic position (anterior shoulder: arm slightly abducted/externally rotated, loss of deltoid contour)
Anterior shoulder dislocation can injure the axillary nerve (regimental-badge sensory loss, deltoid weakness)
Posterior shoulder dislocation: associated with seizures/electrocution ('light-bulb' sign on X-ray) — easily missed

Red flags

Neurovascular injury (axillary nerve in shoulder; sciatic nerve / AVN risk in hip) → assess before and after reduction
Posterior hip dislocation → urgent reduction (avascular necrosis risk rises with delay)

Differentials & how to tell them apart

Fracture (without dislocation)cortical break, joint congruity preserved on X-ray

Fracture-dislocationboth — needs careful imaging and often surgical management

Rotator cuff tearweakness without loss of joint congruity

Investigations

X-ray BEFORE and AFTER reduction (confirm direction, exclude associated fracture and confirm relocation); document neurovascular status pre- and post-reduction; CT for complex/fracture-dislocations.

Management

Prompt closed reduction (document neurovascular status) + immobilise + rehabilitate

1Confirm with pre-reduction X-ray and document neurovascular status. Provide analgesia/sedation and perform prompt closed reduction, then re-check neurovascular status and obtain a post-reduction X-ray.Gate: Always document neurovascular status BEFORE and AFTER reduction (e.g. axillary nerve in shoulder dislocation); a posterior hip dislocation needs urgent reduction to limit avascular necrosis.
2Immobilise and rehabilitate; surgery for irreducible, recurrent (instability repair) or fracture-dislocations.

Analgesia/sedation + prompt closed reduction — with appropriate technique; assess and document neurovascular status before and after

Immobilise then rehabilitate — sling/splint, then physiotherapy to restore function and stability

Surgery — for irreducible, recurrent (e.g. recurrent shoulder instability — Bankart repair), or fracture-dislocations

Reduce prosthetic dislocations / address recurrent instability — orthopaedic input

Key points

Reduce promptly and document neurovascular status before AND after. Anterior shoulder dislocation (commonest) risks the axillary nerve (regimental-badge numbness). Posterior shoulder dislocation follows seizures/electrocution and is easily missed ('light-bulb' sign). Posterior hip dislocation → urgent reduction (AVN risk).

Monitor & prognosis

Neurovascular status, post-reduction imaging, recurrence/instability.

Most do well after reduction; recurrent instability or fracture-dislocation may need surgery.

Source: BOAST; orthopaedic guidance