What is Acromioclavicular seperation?

The acromioclavicular joint is situated above the shoulder, ball and socket joint. The Separation of the two bones forming the AC joint is caused by damage to the ligaments connecting them. It is sometimes also referred to as a shoulder separation injury.



Possible Cause of the injury



 The injury can be caused by in normal daily living by falling and landing on either your elbow / shoulder, or onto an outstretched hand bracing for impact.



 In sport the AC displacement is commonly caused by an impact injury and is associated with contact sports like rugby. An example of this is during a hard tackle. It is also common in gym exercises like the downwards phase of a pull up and a weight lifting exercise like the common should press. In both of these situation the joint and its ligaments are placed under increased stresses, these are usually damaged due to the movement being performed too fast, or too much weight being used.



Anatomy



Bones: The acromioclavicular joint is formed by the outer end of the clavicle (collar bone) and the scapula (shoulder blader) at its acromion process. The acromion process is a bony prominance on the upper part of the scapula. This forms the highest point of the shoulder, which you can clearly see pertruding. There is also the coracoid process that help forms the joint pertruding laterally (outward) over the shoulder joint.



Ligaments:The main ligament of the AC joint is the acromioclaviculare ligament (AC ligament). The other ligaments that can be found to be part of this joint are the coracoclaviculae (CC) ligament and the coracoclavicular joint.



Symptoms

•   Pain at the end of the collar bone


•   Pain may feel widespread throughout the shoulder until the initial pain resolves, following this it is more likely to be a very specific site of pain over the joint itself.


•   Swelling often occurs


•   Depending on the extent of the injury a step-deformity may be visible. This is an obvious lump where the joint has been disrupted and is visible on more severe injuries


•   Pain on moving the shoulder, especially when trying to raise the arms above shoulder height

AC joint injuries are graded from 1-6. This scale This is known as the Rockwood scale that grades the injury in relation to the extent of ligament damage and the space between the acromion and clavicle.



Grades:



Grade 1 - Simple sprain to the AC joint.



Grade 2 - Rupture of the aC ligament.



Grade 3 - Rupture of acromioclavicular and coraoclavicular ligament, resulting in displacement.



Grade 4 - Posterior (Behind) displacement.



Grade 5 - Superior displacement, more so than at stage 3, upto 4 times normallity.



Grade 6 - Complete rupture of ligaments causing full displacement of the clavicle.



Treatment

•  Rest and apply ice as soon as possible.

•  Once ice has been placed on the area for 1 - 2 days, you can use heat cream to help the joint repair.

•  Depending on what stage you are in, you could place arm in sling to releave joint of weight.

•  See sports injury therapist, physio or doctor for further advice or treatment.

WARNING: If this injury is neglected and allowed to heal out of place this could increase the wear and tear on your joint causing you problems in the future.