When discussing treatment options with your surgeon, if the primary working diagnosis is impingement syndrome or you have been told you have a spur that needs to be removed in your shoulder, we would highly suggest you consider a second opinion before undertaking any invasive treatment. Impingement syndrome first became a dominant part of the shoulder lexicon in the 1970s as a catchall term for many different types of shoulder pathology. With modern diagnostic tests and vastly improved knowledge, we now understand that there are even more possible reasons for so called “shoulder impingement” and it is vital to establish the primary reason for this and not rely on the general nonspecific diagnosis of just plain impingement. While many patients and physicians continue to fixate on the belief and picture of a growing spur in the shoulder that is gradually eroding or tearing the rotator cuff, the evidence and current shoulder experts highlight that this belief is clearly erroneous and acromioplasty is likely one of the most over utilized surgical procedures today. It is also important to understand that the spur isn’t really out in space as is appears on the x-ray, but rather represents bone formation within the very important CA Ligament (coraco-acromial). The current evidence suggests that because of some process that interferes with the depressor effect of the rotator cuff or causes repeated stress and “impingement” on the CA ligament, the CA ligament gradually turns to bone (ossifies) in an attempt to reduce this stress and contain the resultant proximal migration of the humeral head. Here are several key articles highlighting this issue further: http://jbjs.org/article.aspx?articleid=6111 and http://jbjs.org/article.aspx?articleid=147549
The rate of “spur removal” or acromioplasty has grown so significantly that starting in 2012, the CPT code for arthroscopic acromioplasty can no longer be reported as a primary diagnosis: “The status of the CPT® code +29826 changed from a standalone to an add-on code in 2012. This means that you can now report this only when your surgeon does another scope procedure as the primary procedure.”
There is also evidence that a “spur removal” or acromioplasty does not help or prevent progression of rotator cuff tears: http://www.bjj.boneandjoint.org.uk/content/80-B/5/813.full.pdf
Several authors have opined that because acromioplasty is a relatively simple procedure to perform, this is likely a factor contributing to over utilization. The shoulder is considered by many to be the most complex joint in the human body; the false promise of a relatively quick recovery and simplicity of spur removal can be highly seductive for patients suffering with longstanding shoulder pain.
To start the process of getting a better understanding on what may be responsible for your shoulder pain, we have to start with some basics about shoulder function:
The shoulder is really the shoulder girdle (or pectoral girdle), which includes 5 different joints: 3 real or anatomic joints and 2 physiologic or false joints.
The shoulder girdle is only connected to the rest of the skeleton at the sternum (breastbone), the sternoclavicular joint. This means that the shoulder girdle developed with minimal bony stability in order to maximize mobility. So shoulder motion is really a complex coordinated dance involving movement of the shoulder blade (scapulothoracic) and shoulder (glenohumeral) joints. Although traditionally this relationship is described as a 2:1 glenohumeral: scapulothoracic ratio, the actual ratios are much more complex and dynamic as outlined in this study: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3377910/
This intricate dance of shoulder motion has been likened to a seal balancing a beach ball. The goal of all of the muscles involved in this coordinated dance is to preserve a stable center of rotation for the shoulder joint. Muscles require two relatively fixed points to work most efficiently, and if a stable center or rotation is lost, the muscles involved tend to shut down (become inhibited) and weaken. So it is easy to see that for simple and slower movements, it is relatively easier to control the position of the shoulder. Conversely, for complex, high speed, overhead, and repetitive activities it is much harder to maintain a stable of center of rotation, which ultimately can result in shoulder pain when injury. A recent article outlining the scapula’s role in impingement and shoulder pain is here:
This gives us a basic background on being able to understand why many other reasons and injuries may also result in shoulder pain and impingement, for instance a pinched nerve can weaken a subset of muscles disrupting the coordinated movements of the shoulder girdle, resulting in pain and injury. Grasping for a quick and easily available solution can be very seductive, especially when you are suffering with pain. Take the time to establish a clear and comprehensive diagnosis before moving ahead with shoulder surgery. Simple problems often can be solved with simple solutions; complex problems often require a deeper level of understanding to arrive at an effective solution. Unfortunately, failed shoulder surgery can be a complex problem that first started because of the false promise of a simple solution.