Part 1:
The acromioclavicular joint is the joint between the collar bone and shoulder blade. Stability and attachment of the collarbone to the shoulder bone is secured via three ligament: acromio-clavicular and coracoclavicular ligaments. Injuries to these ligaments result in displacement of the clavicle. The injury is usually caused by a fall onto the outstretched hand.
Part 2:
In AC joint dislocations, the collarbone cam displace completely. Surgical treatment is then advised.
There are two principle treatment options:
1. Fixation with buttons and sutures. This can be done with keyhole surgery
2. Using a plate with a hook to allow the ligaments to heal. This technique requires plate removal
Part 3:
Here are some further considerations. Unless completely displaced most people will cope well. However, if you are commonly use your hand overhead, are a high demand athlete, surgery should not be the first choice.
If indicated surgery should be performed early; in the later stages the ligaments then need to be reconstructed with your own tendons. This is more extensive surgery and requires longer rehabilitation. Below an example of reconstruction with tendon material
