Shoulder pain can have many different sources including instability, a rotator cuff tear, a labral tear, arthritis, inflammation, bone edema, tendinosis, a pinched nerve, etc. More and more studies continue to show that shoulder MRI results often cannot predict why the patient is experiencing pain.

This is the case for various body areas including the lumbar spine, knee, and certainly shoulder. The MRI can provide a lot of good information, but it has been repeatedly shown not to substitute for a thorough history, exam and a diagnostic ultrasound by the physician. This takes time and focus.

Although most patients and providers will blame the rotator cuff tear as the cause of pain, it is never a given that a rotator cuff tear is actually the source of the pain. In fact, the studies we will cover in this article show that it is often inaccurate to assume that a rotator cuff tear is what is causing your shoulder pain despite what is seen on an MRI. Let’s dive a bit deeper into rotator cuff tears, surgery, and determining the cause of your shoulder pain.

What is a Rotator Cuff Tear?

The rotator cuff is a complex series of muscles and tendons that surround the shoulder and help lift the arm and stabilize the shoulder joint. A rotator cuff tear is simply a tear in the tendon usually close to where it attaches to the bone. While some rotator cuff tears result from trauma, the vast majority happen from wear and tear as we age – this is referred to as a degenerative tear.

The most common cause of a rotator cuff tear is simply a slightly more demanding movement than usual. How might this happen? It has been known for a considerable amount of time that the rotator cuff does not have a great blood supply which makes it harder for the body to heal an injury in that area.

So, what is the problem? It is likely to be a lack of healthy progenitor cells and stem cells to repair the damage as it occurs over time, and at some point with little provocation, the unhealthy tissue simply fails and a tear occurs.

What Happens During Rotator Cuff Surgery?

Rotator cuff surgery involves cutting into the shoulder and stitching the tear back together. Recovery time from surgery can be lengthy and there is a good amount of research showing that this surgery is often ineffective for many types of rotator cuff tears. The tissue is often too weak to stay together with a stitch.

In larger tears, approximately 6 in 10 do not heal properly, even with surgery. For patients over 60, shoulder surgery recovery is even more difficult, with 1 in 3 rotator cuff tears not healing.

It is also notable that a good number of surgical patients never return to their full range of motion following surgery and pain can linger. Additionally, many studies show that shoulder pain prior to surgery actually has little to no correlation with the rotator cuff tear or the severity of the tear. So, what is causing the pain?

Shoulder Pain and Inflammation

One study performed in Japan analyzed joint fluid obtained from 38 patients before and after orthopedic rotator cuff surgery for various chemical messenger molecules (cytokines). These cytokines work for the immune system and call our immune cells into action when there is inflammation, infection, or trauma.

Imagine that our immune cells are like firefighters, always ready and waiting. The firefighters might be at the station cleaning trucks, training, or stocking their equipment, but when that alarm sounds, they jump into action and race to the fire. For us, that alarm is our cytokines, and when it sounds, our immune cells race straight to the inflammatory fire as our first responders.

Interestingly enough, the study that we referenced earlier concluded that larger rotator cuff tears were associated with less pain and that more pain was accurately predicted by more IL-8 (interleukin 8) in the joint fluid. IL-8 is an inflammatory cytokine or an alarm sounding when inflammation is present. The pain that was studied in this study was due to the inflammation and not the tear itself.

Another study states that “the prevalence of full-thickness rotator cuff tears increases with age [and] many patients are asymptomatic and may not require surgical repair.” Even while there was pain present, the study concluded that physical therapy rather than surgery should be sufficient to address the symptoms in most cases.

Does Rotator Cuff Repair Surgery Fix Pain?

Unfortunately, the answer is no. One study proved this disappointing result that rotator cuff repair does not fix pain or function in the shoulder. This should be eye-opening for patients, whose primary goal for undergoing a rotator cuff repair is to reduce or eliminate their pain. There are countless studies showing that shoulder pain is often not due to the presence of a rotator cuff tear. If a surgeon repairs a tear in your rotator cuff to eliminate your pain, but your tear is not the actual source of your pain, why was it necessary to have the surgery? It may be that the tear caused inflammation which thereby causes the pain. Sewing up the tear may not get rid of the inflammation.

Why not use Cortisone or Anti-inflammatories to get rid of Inflammation?

The problem is that cortisone gets rid of inflammation at a cost. The tissue gets even weaker and unhealthier. The local stem cells are damaged or killed leaving the tissue in worse condition than it already was in. If someone receives a cortisone injection within a year of a rotator cuff repair, it is more likely to fail and need a revision.

In regards to NSAIDS, aside from the myriad of systemic problems they can cause (gastrointestinal bleeding, kidney damage, stroke and heart attack to name a few), they also have been shown to inhibit tendon healing and in Regenexx’s laboratory, they have been shown to negatively impact stem cells.

The Best Alternative

If the reason that the rotator cuff fails in the first place is a lack of local stem cells, doesn’t it make logical sense that replacing those cells is critical to get the structure as healthy as possible?

What if you could avoid rotator cuff surgery and have a much quicker recovery? Well, for about 70-80% of rotator cuff tears, you can. We have pioneered a procedure to do just that over the last 14 years that includes an ultra-precise injection of your own stem cells under image guidance using a patented protocol.

Treating Shoulder Pain With Stem Cells


Rotator cuff tears are one of the most commonly treated conditions at Regenexx Tampa Bay, and we consistently see successful outcomes in these patients. With that said, while most tears will heal with just a precise injection, there are a few massive tears that are unlikely to be helped without surgery. Keep in mind that even after surgery to repair a massively damaged rotator cuff, stem cell injections may assist in the healing and improvement of the tissue. For example, one study showed that using stem cells after surgery
reduced the retear rate by half.  

The Regenexx procedure addresses more than just the rotator cuff tear. Precise injections of the surrounding ligaments improve stability, injections of the other non-torn rotator cuff tendons and biceps tendons improve their strength and function, injections of the labral tissue, when there is evidence of damage, strengthens that tissue and injections of the joint and cartilage can improve any arthritis that is present.

In some cases, when there is edema (swelling) in the bone itself seen on MRI (which represents small microfractures), injections will help heal the bone. There may even be a component of a pinched nerve in the neck that is contributing to the pain and accelerated degeneration of the tissue in the shoulder. In these cases, platelet lysate injections around the nerve (epidurals) can help as well.

Following the procedure, skilled physical therapy will likely be recommended. For our patients in the Tampa Bay region, we recommend physical therapy at our Tampa location with EXOS. As you can see, this is a comprehensive plan to get you back to the activities you love to do.

Whether you’ve had surgery to repair your rotator cuff or not, Regenexx may be able to help you with your shoulder pain. Contact us today to find out how.

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