When the ligaments that hold the collarbone in place are injured, AC joint dislocation occurs (often after a fall, e.g. riding a bicycle). AC joint dislocation is broken down into several stages.
Grade 1 is a stretching of one or more ligaments. There is no problem with the stability of the collarbone, but you feel pain.
Grade 2 is a tear in part of the ligaments, but 1 of the 3 ligaments remains intact. This causes partial instability: when you push on the end of the collarbone, you can trigger a limited up-and-down movement that is painful. The risk of persistent pain after initial treatment is greater than with grade 1 injuries.
Grade 3 injuries are characterised by the complete tearing of all the ligaments holding the end of the collarbone in place: the collarbone is clearly raised, at shoulder level. You feel pain and experience a clear loss of function in the shoulder.
There are further grades (grades 4 to 6) where the overlying muscles are torn, the skin is broken or the collarbone is dislocated backwards. In these cases, surgical intervention is necessary.
Read more about AC joint dislocation here
Your treating doctor will discuss the treatment options with you.
