Acromioclavicular joint (ACJ) dislocations commonly occur following a fall or a blow onto the point of the shoulder.  They are a common sporting injury.  A prominent lump will usually be present on the point of the shoulder.

ACJ injuries are graded according to the Rockwood classification system into grades I to VI.  

Low grade type I and II injuries involve capsular sprain injuries without rupture of the critical coracoclavicular ligaments.

Grade III to VI injuries denote injuries in which the coracoclavicular and acromioclavicular ligaments have ruptured and the clavicle displaces upwards giving the characteristic appearance of the lump on the point of the shoulder.  

Grade IV to VI injuries are high grade injuries and surgical reconstruction is usually recommended.  

Grade III injuries, in certain circumstances are treated with surgical reconstruction.

Dr Cutbush performs reconstruction of acute AC joint injuries using an all arthroscopic technique. He has recently had an article describing this all arthroscopic technique accepted for publication by the prestigious international medical journal the Journal of Shoulder and Elbow Surgery in their techniques in shoulder and elbow surgery.