Shoulder pain is a common complaint. In fact, I’d estimate that it is one of the most common complaints I see. In most cases, the diagnosis is rotator cuff (not “cup”) strain or tendinopathy. The good news is, most of the time, it’s non-operative. That means it likely won’t require surgery. It also does not require an MRI for the diagnosis, contrary to common belief.
First, let me review the anatomy in basic terms. The shoulder joint is a ball and socket joint. The socket is very shallow, which allows for the great range of motion we have in the shoulder. However, this makes the role of the rotator cuff critical. The rotator cuff is made up of four tendons, and these tendons stabilize the humeral head (top of the arm bone) in the shallow shoulder joint. When these tendons as a group are weak or not working properly, other structures become impinged, causing pain. I must also mention the scapular stabilizers (trapezius muscles, rhomboids, etc.) here. In addition to the rotator cuff, these muscles are critical for normal shoulder motion because the glenoid, or the “socket” part of the joint, is actually part of the scapula, or shoulder blade. Often times scapular motion suffers as a result of shoulder pain, but it also commonly contributes to the discomfort. Over time the muscles and tendons can become weak or imbalanced as a result of overuse or poor mechanics. This results in a tendinopathy, or prolonged injury to the tendons.
When evaluating shoulder pain, I assess range of motion and strength of the rotator cuff, in addition to some special testing. The history, physical exam, and x-rays often tell me what I need to know, without having to rely on advanced imaging. Many of my patients think they need an MRI to rule out a rotator cuff tear, and sadly, some physicians will order one automatically when they hear “shoulder pain.” Here’s the thing: the likelihood of a rotator cuff tear increases as we age. And like I said, the physical exam can tell us a lot. So if I see a 25 year old male with gradual onset of pain who demonstrates good range of motion and strength on exam, I am not suspicious for a full-thickness tear. However, if I see a 65 year old female with severe pain after a fall or other trauma, I am more suspicious for a tear, and I will order the MRI to evaluate.
The good news is, young to middle-aged folks respond very well to conservative treatment and rehab (which usually involves physical therapy). Re-training the rotator cuff muscles and tendons, in addition to the scapular stabilizers, is critical to the treatment plan. This isn’t something that gets better overnight, but it should improve with time as the shoulder mechanics improve.
The treatment of rotator cuff tears is not always so simple. Full-thickness tears are quite painful and will not heal on their own, requiring a surgical repair. However, many partial-thickness tears can be treated conservatively. While they won’t heal, per se, they will “quiet down” and become less painful over time. Unfortunately, there is no way to predict which partial-thickness tears will progress to full-thickness tears and which ones will become less troublesome.
Of course, there are exceptions to the rule, and I won’t belabor those points here. It would require another post to address injuries specific to throwing athletes, another to address instability in the shoulder, and another to address injuries of the acromioclavicular (AC) joint. So that’s it for now. When in doubt, see a sports medicine physician who understands common pathology in the shoulder and can make appropriate treatment recommendations based on your particular problem.