Q: I'm trying to figure out what to do about my shoulder. The X-ray shows a big bone spur under the part the surgeon called the acromion. The rotator cuff is torn and I have something the physiotherapist calls scapular dyskinesia. Everyone has a different idea about how to treat these three problems. Is there any one-way to go or even an order of steps that should be followed?

A: You are not alone in this dilemma. Many adults experience shoulder pain. One of the most common causes of mechanical shoulder pain is a problem labeled subacromial impingement syndrome or SIS. The term impingement tells us something is getting pinched. Impingement syndrome occurs when the rotator cuff tendons rub against the roof of the shoulder, the acromion.

Although SIS is one term, it actually represents a wide range of underlying pathologies. There could be a bursitis, rotator cuff tendinopathy, fracture, calcific tendinitis, or other change in the local anatomy contributing to the problem.

There are many factors that when present combine together to result in subacromial impingement syndrome. Aging with its many degenerative processes isn't always very kind to the shoulder. Bone spurs form, the rotator cuff and other soft tissues fray and wear thin, and trauma all add to the development of mechanical shoulder pain. Loss of blood supply to the area is another reason why these problems occur.

Subacromial impingement syndrome and rotator cuff degeneration go hand-in-hand together. Much debate and controversy exist over the connection between these two conditions. Which comes first? Does the impingement cause tearing of the rotator cuff? Or does the rotator cuff degenerate and weaken over time resulting in impingement?

A natural consequence is a change in the way the muscles and tendons contract and work together to move
the scapula (shoulder blade). This will make more sense if we review a little anatomy. The bones of the shoulder are the humerus (the upper arm bone), the scapula (the shoulder blade), and the clavicle (the collar bone). The roof of the shoulder is formed by a part of the scapula called the acromion.

The main shoulder joint, called the glenohumeral joint, is formed where the ball of the humerus fits into a shallow socket on the scapula. A false joint is formed where the shoulder blade glides against the thorax (the rib cage). This joint, called the scapulothoracic joint, is important because it requires that the muscles surrounding the shoulder blade work together to keep the socket lined up during shoulder movements.

When the scapula and glenohumeral joint aren't coordinated in their movements, a problem called scapular dyskinesia develops. Dyskinesia is another way of saying "incoordinated." Most of the time, the three problems you are faced with (bone spur, rotator cuff degeneration, scapular dyskinesia) occur together. We aren't sure exactly which came first or how to best treat these problems.

We are slowly identifying all the various factors involved and beginning to unwind cause and effect. Each patient will have his or her own unique combination of reasons why they developed an impingement syndrome.

There is nothing wrong with trying the least invasive approach first. Assess the results and proceed from there. It may be that combining different methods will yield the best results. But we suspect that the individual trial-and-error approach is necessary for now.

Until high-quality research answers all the questions of what and why, it is suggested that nonsurgical management has good overall results and should be the way to go first. Surgery can be equally successful in the hands of an experienced surgeon but should be reserved as the last resort.

Reference: Alicia K. Harrison, MD, and Evan L. Flatow, MD. Subacromial Impingement Syndrome. In Journal of the American Academy of Orthopaedic Surgery. November 2011. Vol. 19. No. 11. Pp. 701-708.