Hi, and thanks for your medical question on eHealth's Ask a Doctor forum.

Well, degenerative arthrosis of the acromioclavicular articulation is basically an arthritis which is degenerative in nature-ie, it happens because of age. This happens when the shoulder joint is used often, then with age the degenerative changes in the cartilage of the joint (between acromion of the scapula and the clavicle or shoulder bone) start earlier as in your case (at 54 years). With time bony spurs (osteophytes) develop which cause pain, indent the subacromial fat and at times cause it to efface or move out of its place. Another cause is an old injury to the shoulder joint.

Usual treatment prescribed for arthritis is followed here also : physiotherapy, pain killers and anti-inflammatories, injection of steroids or painkillers into the joint or in very advanced cases surgery. At times effacement of the subacromial fat restricts the shoulder movement to such a stage that surgery is recommended.

However without examining the patient, the presentation of symptoms, looking at X-rays and MRIs, it is difficult to prescribe a correct line of treatment on net. Please consult an orthopedic specialist. Hope this helps. Take care!