ACJ Dislocations

Acromioclavicular Joint Dislocations

The Acromioclavicular Joint is usually injured by a direct fall onto the point of the shoulder. The shoulder blade (scapula) is forced downwards and the clavicle (collarbone) appears prominent.



The degree of damage to the joint is classified by the joint displacement and injury to the ligaments which support the AC joint.: 

Grade 1                                            Grade 2
AC joint sprain                                  AC joint ligaments torn only 

Grade 3                                             Grade 4
100% dislocation                              clavicle dislocated backwards 

Grade 5                               Grade 6
>100% dislocation                clavicle under coracoid

Complete Classification:


Traditionally the grade determined the treatment. However the evidence for this is poor. We therefore treat according to the symptoms - i.e. pain and functional limitations.

Considerations for surgery:

  1. Most people with ACJ injuries can cope, unless overhead or high demand athlete
  2. The long-term outcomes are similar with or without surgery
  3. Traditional techniques carry a failure rate of approximately 20%

Treatment algorithm:

  • Acute injury (< 1week): 
    • Assess and diagnose. 
    • Sling and analgesia and arrange to review in 3 weeks. 
    • Surgical reduction and fixation if: Clearly in agony with clavicle button-holed through trapezius; Neurovascular injury; Open injury
  • 3 week review:
    • Settling and improving – continue symptomatic management and gradually reintroduce sports and manual activities. Arrange review at 3 months.
    • Not coping – offer early surgical stabilisation
  • 3 month review:

For Grade 1 injuries removal of the damaged joint is performed. This is done by keyhole surgery (arthroscopically) and is known as an Arthroscopic ACJ Excision .
A Subacromial Decompression is usually done at the same time.

For unstable AC Joints and symptomatic complete dislocations (Grade 3, 4 & 5) injuries the collarbone and shoulderblade need to be re-aligned and fixed in place. Numerous surgical options exist and your surgeon will discuss this in more detail with you. For more information on the surgical stabilisation procedures Click Here .

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