Shoulder Pain

Understanding Shoulder Pain: What is the real root-cause of the pain? 

Shoulder pain is the second most common presenting symptom that I see in my practice (after knee pain). The pain usually starts in certain positions or movements. Patients often complain that they can’t sleep on that side or have restricted range of motion. As always, it’s important to understand the root cause of pain and make a proper diagnosis of the primary pain generators. 

Once we understand that the real root-cause mechanism of pain is instability and damaged (stretched), highly innervated, capsular and tendinous attachments we need to understand how imaging (x-ray, MRI and ultrasound) can help us understand the problem. We also need to understand the limitations of these imaging tests in helping us understand the root cause of the pain and what are the real primary pain generators.

Let’s start with x-ray. Experienced clinicians have long known that the severity of degeneration seen on x-ray is poorly correlated with pain. Some patients have very advanced OA and little pain. Others have mild changes and much more pain. Why? The key here is to understand joint health and pain in terms of stability. Yes, a severely degenerated joint on x-ray may be more likely to be more unstable but not necessarily so. Hence a diagnosis of arthritis based on x-ray should always be supplemented with an evaluation of the stability of the joint with range of motion and palpation interrogation. Arthritis means degeneration of the joint but it’s not the bony and cartilage component loss seen on x-ray that causes most of the pain but primarily the accompanying instability. The pain generators on the surrounding ligament and tendon component of the arthritis which cause looseness (instability) are much more sensitive than the pain generators on the bone or meniscus. The greater the degeneration and looseness of the capsule, the more pain is caused by pulling on damaged attachments. 

MRI, because it evaluates connective tissue, is particularly useful to identify rotator cuff tears. However, one of the problems with MRI is it usually fails to identify capsular tears because of poor tissue contrast. Also, as far as the rotator cuff, MRI cannot differentiate between asymptomatic tears and clinically relevant tears. If we did MRI’s on the shoulders of a general population you would see many patients with tears, that have no pain or limitations. In addition, a very important limitation is that MRI is not sensitive enough to identify micro-tears. So what you see on MRI may be important but it also often may miss the true underlying cause of the problem. MRI is useful but a doctor requires good physical exam skills, especially palpation interrogation, to get the complete picture. Over-reliance on MRI can be misleading.

Ultrasound can also be very useful. Here you have the advantage of being able to test structures under movement. This can help us evaluate stability and if complemented with good palpation interrogation skills can be very helpful to help diagnose the root cause of pain. However, as with MRI, you may see abnormalities that are not pain generators and, on the other hand, as with MRI, it is often not sensitive enough to detect microtears that are so often a major contributor to the pain picture. Also, ultrasound misses capsular tears because they are too deep and out of the range for our current ultrasound technology.  

Many years ago, I had the privilege of attending medical school at McGill University (McGill ‘80), one of the best schools in Canada, often called the Harvard of the North. As a student in my orthopedic rotations, my teachers would drum into me the importance of having a methodology as you assess patients.  First, they would stress the importance of listening to the patient. They would say that the patient is trying to give you the diagnosis so listen carefully to their history. In the case of the shoulder, trouble lying on it or pain with certain movements suggest instability of the joint and tears/microtears in the rotator cuff. Then they would stress the importance of a thorough physical exam. In the case of the shoulder a ROM and full palpation interrogation scanning of the entire shoulder, upper back and neck complex is essential. The myofascia is all connected, and pain can refer just like nerve pain. Where you feel the pain may not be the origin of the pain. Only after this kind of systematic routine, would they suggest further testing.

Of course they didn’t have the fancy MRI, x-ray and ultrasound testing we have today, but I’m pretty sure they would disapprove of the modern surgeons who recommend surgery almost solely based on MRI without paying too much attention to basic history and physical findings. As we have discussed, x-ray, MRI and ultrasound all have their place but they also have their limitations and should not be over relied upon since they may miss critical diagnoses such as instability of a joint and /or microtears in the ligaments and tendons that are so often the main root cause of the pain.

A proper physical exam should include range of motion testing, stress testing of the components of the rotator cuff and palpation interrogation of all structures to pinpoint where they are damaged. It is also true that most patients will have multiple structures that are damaged, not just one. A proper exam includes an assessment of both the underlying joint (including the capsule and extra-capsular ligaments) and the overlying rotator cuff. Microtears in multiple structures are often present, even when a larger tear in a single structure is identified. Ignoring these microtears can lead to incomplete healing and poor results. Surgically fixing one structure (e.g. supraspinatus) with a large tear while ignoring capsular instability and other areas with microtears may yield only mediocre results and result in a high failure rate. This is where regenerating ligamentous and tendinous attachments at a cellular level as we do with stem cells and PRP, may yield a far superior outcome.

In shoulder OA, the main underlying cause of pain is instability of the joint and a loose or stretched capsule. In rotator cuff pain, the culprit is instability and tears / micro tears of the rotator cuff that surrounds and moves the joint. A good  regenerative specialist can use palpation interrogation to identify both types of problems. As we have said, most patients will have multiple pain generators with both primary shoulder instability (shoulder OA) and multiple rotator cuff tears (and micro tears), only some of which will show up on MRI. The only way to make a comprehensive and proper diagnosis of all the real root causes of the joint pain is with a thorough exam including range of motion testing and palpation interrogation of all structures in the area. Of all the tests you can do, palpation interrogation done by an experienced regenerative doctor, may be the most important. Not only can it identify all the structures that are damaged and causing the pain but you can also prioritize the pain generators in order of importance.

Labral tears can occur frequently, either acutely from falling on an outstretched hand or from wear and tear over time. SLAP lesions are sometimes treated with surgery, as are tears in the biceps tendon. Both rotator cuff tears and labral tears are often seen on MRI and may or may not be causing pain. There is debate in conventional circles whether surgery is any better than conservative measures in terms of outcome. This is especially true in overhead athletes like baseball pitchers who want to return to their sport. Data suggests that they may have a better chance of returning to their sport if they avoid surgery and treat the problem conservatively with physical therapy. Augmenting these conservative measures with high-quality stem cell therapy would greatly improve the chances of a good outcome.

Osteoarthritis (OA) of the shoulder is perhaps the most common issue I evaluate. The data on shoulder replacement surgery does not show great outcomes and suggests that this surgery should definitely be a last resort. In my view, all four of these clinical groups can be excellent candidates for regenerative approaches. Why? Because in all of these cases, the primary driver of pain is shoulder instability. For those patients who have days where the shoulder hurts more, it is because the joint is more subluxated. On physical examination, instability commonly presents with snapping, crackling, or popping sounds as you move the shoulder through its range of motion.

Frozen shoulder or entrapment syndrome refers to a severe restriction and a locking and limitation of abduction (raising the arm laterally). Frozen shoulder is caused by more significant instability and is usually accompanied by moderate to severe OA. Frozen shoulder is caused by a superior subluxation of the humeral head, which pinches the supraspinatus tendon against the acromion process. A small subluxation gives clicking on abduction; a larger subluxation jams the humeral head against the acromion. Frozen shoulder is a sign of serious capsular instability, particularly laxity of the posterior capsular ligament bundle.

Another fairly common problem is AC (acromio-clavicular) joint sprain or dislocation. This generally occurs from a forceful impact to the outside of the shoulder as occurs most commonly in contact sports like football. There are six grades to AC joint separation ranging from grade I where the ligament has a very small tear or is  merely stretched. Grade II is a partial joint dislocation. This injury results in the acromioclavicular ligament being torn completely, though the coracoclavicular ligament is still in good shape. In Grade III: the joint is completely separated. Both ligaments (acromioclavicular and coracoclavicular) are torn. Here you can readily see a bump that appears on the shoulder. Higher grades: grades IV-VI exist, but they’re usually a result of a serious motor vehicle accident, so they’re not as common as the lower grades.

Each grade of shoulder separation will have its own set of symptoms to look out for. In Grade I the AC joint will be tender to palpation and you may feel minor pain when you move your arm. With Grade II, there is more pain and perhaps some swelling in the area. For a grade III injury, symptoms become more serious and patients may notice popping when they move the joint. At this stage there is  noticeable shoulder deformity and patients may require a sling to minimize movement. Although the diagnosis is usually straightforward with obvious tenderness and swelling some doctors will likely get an x-ray to confirm the diagnosis and depending on the injury involved, to differentiate a shoulder separation from a bone fracture.

Surgery for AC joint separation or dislocation does not really work well. Fusing the joint (arthrodesis) with screws and wire doesn’t work since you need movement to use the arm properly. Surgical excision of the joint (called decompression or arthroplasty) also has a poor outcome because it results in an unstable joint where the end of the acromion floats and can interfere with other structures. A recent study in a surgical journal suggested that surgery was no better than doing nothing and maybe worse. Researchers found no clinically improvement in the group that underwent surgery for their AC joint dislocation, and no differences were found in function between the two groups. However, the conservative management group with no surgery recovered and returned to work faster. Those who had surgery had a much longer recovery and more complications.  

So we can add AC dislocation surgery to a growing group of unnecessary orthopedic surgeries which result in worse outcomes than doing nothing. Like removing a piece of the knee meniscus shock absorber which results in less cushion for the joint and accelerates OA. Or fusing some lumbar spine vertebrae that ends up putting more stress on the vertebrae above and below the fusion and causes them to break down more quickly.

Treatment Options: Surgery vs. Regeneration with Stem Cells 

Arthroscopic shoulder surgery or even complete replacement are often recommended as a potential treatment, but there are risks involved. Recovery may be slow, requiring several months of restricted use followed by a period of rehabilitation. In some cases, full functionality and movement are not achieved. In the case of arthroscopic repair, retear rates might be as high as 20% or more, and the incidence of post-surgical stiffness is high. Researchers attribute the high retear rate to the tendons not healing properly. This highlights a key difference between regenerating tissue at a cellular level and mechanically sewing it together. When tissues are regenerated, they have much better blood flow and are much stronger than if they are simply sewn together. This is one reason why patients should consider regenerative injections before opting for surgery. They may have a better outcome, lower risk and less downtime.

Advantages of Regenerative Therapy 

Regenerative Injection Therapy with stem cells, PRP and/or Prolotherapy can be highly effective for most shoulder issues and has several advantages over traditional surgical methods:

  1. Comprehensive Healing: regenerative treatments can target all key structures in the shoulder, including the rotator cuff, capsule, extra-capsular ligaments, and cartilage. This comprehensive approach can address all the underlying causes of instability, those seen on MRI and ultrasound as well as the capsular laxity and multiple regions of microtearing that might not show up in imaging  studies and may have been clinically overlooked. 
  2. Improved Blood Flow: Regenerated have better blood flow compared to surgically repaired tissue. This enhanced blood flow aids in the healing process and reduces the risk of re-injury.
  3. Higher Success Rates: Studies have shown that regenerative approaches have an approximate 85% success rate in treating shoulder problems. This high success rate is attributed to the therapy’s ability to address the root causes of instability and promote long-term healing and joint health.
  4. Minimizes Retear Risk: Since stem cells and regenerative treatments rebuild tissue at a cellular level, the newly formed tissue is stronger and more resilient. This reduces the likelihood of retears compared to traditional surgical repairs.

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