Your shoulder has two joints.  The glenohumeral joint is where the ball and socket meet and is enveloped by the muscles of the rotator cuff and the joint capsule.

The AcromioClavicular (AC) joint is where the shoulder blade, or Acromion, and collarbone, or Clavicle, meet.  This joint often has arthritic wear and tear changes in people with rotator cuff disorders, but it, too, can generate pain independently. Pain from the AC joint is felt in the top and front of the shoulder when your arm is brought across your chest.  Cortisone injections within the AC joint may alleviate your pain.

Alternatively, you may undergo a surgical treatment for this problem.  This is one of the few joints in the body that can be removed without any undue harm.  By removing the end of the collar bone, there are no longer two worn down surfaces to rub against each other and cause pain.  With the same three or four ¼ inch incisions around the shoulder that are used for your arthroscopic rotator cuff repair, Dr. Kagan will use a bone cutting grinder to remove the end of your collarbone and the pain that comes with it.