Impingement syndrome of the shoulder is a rather common condition associated with aging. Charles Neer first described this condition in 1972. It is felt to be primarily due to scarring of the bursa in the subacromial space of the shoulder between the undersurface of the acromion and the superior surface of the rotator cuff. Associated with this aging is a forming of osteophytes (bone spurs) on both the undersurface of the distal clavicle and the anterior aspect of the acromion which can further lead to scar tissue and pinching of the rotator cuff tissues. As patients develop these changes, repetitive overhead activities may cause irritation of the subacromial space. With time, this chronic irritation can lead to irritation and degeneration of the rotator cuff, which over time, can lead to rotator cuff tears.

The primary treatment of impingement syndrome of the shoulder is to first utilize a 3 to 6 month trial of a rotator cuff and general shoulder strengthening program. On occasion, when symptoms warrant, the judicious use of a subacromial lidocaine and steroid injection may allow the patient to have enough quieting down of the scar tissue in the subacromial space to furthur work on their rehabilitation program.

In those patients who do not respond to the program of physical therapy with or without subacromial corticosteroid injections, operative removal of the scar tissue from the subacromial space and removal of the spurs results in a high incidence of success (85 to 90%) in patients with impingement syndrome. However, it must be recognized that over 80% of patients will get better with an exercise program alone.

In the past, the technique of subacromial decompression was performed using an open incision. The deltoid muscle was taken off the anterior aspect of the acromion and an osteotome and a mallet (a hammer and chisel) were used to remove some of the bone which had the spur formation on it. The thickened and scarred bursa was then removed with arthroscopic scissors or other insruments. The rotator cuff was also searched for any signs of tears and was repaired when necessary. While this technique was found to be very successful, it did result in significant down time for patients as they needed to not use their shoulder for an initial 3 to 6 weeks after surgery to allow the deltoid to heal back to the acromion. In addition, some patients had detachment of the deltoid from the anterior acromion which resulted in significant shoulder disability.

Currently, the majority of subacromial decompressions are performed arthroscopically. In this technique, the surgeon enters the glenohumeral (shoulder) joint with an arthroscope to make sure that there aren't any problems inside the shoulder which could be contributing to pain associated with the impingement syndrome. Any pathology that is seen in the shoulder can be treated with trimming or repairing the injured structures (if possible). Once all necessary treatment has been performed in the glenohumeral joint, the arthroscopic camera is then inserted into the subacromial space or lateral to it. Arthroscopic shavers and coagulators are used to remove the scar tissue and to clean off the undersurface of the bone under the acromion (and distal clavicle when indicated). An arthroscopic bur is then used to smooth off the osteophytes (bone spurs) under the acromion to remove this as a source of impingement. Once the entire acromion has been visualized and it's verified that all scar tissue has been removed as well as all spurs, the procedure is ended. The glenohumeral joint and the subacromial space would be injected with a local anaesthetic and steristrips with or without subcutaneous sutures are used to close the small surgical incisions.

When there are no structures which need to be repaired in the joint, the patient is encouraged to use the shoulder as tolerated in attempt to get the range of motion back as soon as possible. It is well documented that one of the most important things to achieve after a shoulder surgery is to achieve the full range of motion back as soon as possible. If it is not done, even if the initial problem has been treated by the surgeon, commonly the patient will have shoulder pain develop due to stiffness. This pain may sometimes be just as bad as the initial problem. For that reason, we emphasize trying to obtain full range of motion of the shoulder as soon as possible.

Standard protocol for subacromial decompression


Q1. How long is the recovery period for this operation?

A1. The recovery period for the operation depends upon what needs to be done inside the shoulder and also how long the problem has been present. In some cases, the shoulder muscles are so dysfunctional, that even if all the scar tissue and osteophytes are removed, it may take several months to return the strength back to normal.