Differentiating Tendonitis and Tendonosis
Correct diagnosis is the most important step when looking for care and treatment tendon injuries. The correct treatment in tendon injuries (tears, tendonitis, tendonosis) and acupuncture treatment at muscle tendon junctions, bone tendon junctions and the related muscles, can make a world of difference for collegiate and professional athletes who have a urgent timeline and need to get back in the game.
In this article published by the Pacific College of Oriental Medicine, acupuncturist Mark Kastner breaks it down.
By Mark Kastner, LAc
Tendonitis is the single most diagnosed chronic connective tissue disease in Western medicine. It affects every major joint within the body and can make the most well conditioned athlete limp to the sidelines, as the pain can be overwhelming. Whether it afflicts a professional golfer or weekend tennis player, tendon pain is a huge problem affecting all sports.
In our everyday lives, tendon pain also creates major problems. According to statistics of Workers Compensation injuries in California, repetitive motion disease (aka tendonitis) is the leading diagnosis for claims and disability in the state. Over the years, studies have begun to shed new light on this age-old problem, and it is my belief that acupuncture is positioned to play a major part in helping to solve this pattern of chronic pain.
When I began my practice 27 years ago, Cortisone use for tendon pain was a no-brainer for most Western doctors. They didn’t think twice about using it over and over again to alleviate the pain associated with their diagnosis of tendonitis. However, this slowly began to change as some interesting studies began to poke holes in the fundamental understanding of what was really creating that pain. By the mid-eighties, there was indisputable evidence that the paradigm for diagnosing and treating tendon pain had been completely wrong. Histological studies (study of cells) showed that in chronic tendon pain there was a minimal amount of inflammation. (2)
How could this be? Tendonitis is, by definition, "inflammation of the tendon”. But that’s not what they found. It was discovered that there were no inflammatory cells, while the inner tendon fibers had degenerated and were disorganized. (Fig. 2) Many fibers, in fact, had micro tears exhibiting long-term load stress that had caused trauma to the fiber itself. This can be seen clinically as patients with chronic tendon pain will commonly lose strength and function in the associated joint.
You would think this information was so groundbreaking that treatment protocols would have changed to reflect it. However, that’s not what happened. Yes, the amount and frequency of Cortisone therapy has declined, but to this day it continues to be used to treat inflammation that is simply not there in chronic cases. And, in fact, the evidence shows that corticosteroids can contribute to further injury of the tendons fibers. (2)
Let’s go back and take a more detailed look at the studies and see why acupuncture with electro-stimulation can play an important part in helping patients reduce their tendon pain. First, let’s review the basic function and structure of tendons to understand the causation of tendon pathology. Tendons, as we all know, attach muscles to bones. There are two important areas in this connection; they are the tendon muscular junction, and the osteotendinous junction. The muscular tendon junction is where muscle tissue morphs to become tendon fibers and the osteotendinous junction is the area in which the tendon literally grows into the bone called the condyle. These tendon junctions are where the majority of tendon fiber injuries occur.
All connective tissue is made out of collagen fibers, however, tendon fibers are specialized to be able to handle the enormous loads our muscles put on them. Biomechanics studies have shown tendons can handle up to 10 times our own body weight during stress tests. They are able to accomplish this because of a number of interesting characteristics of the tendon itself. Tendon structure is based, as you can see by Fig. 1, on a pattern of fiber bundles that becomes smaller and smaller throughout the tendon. These fibers are made up of collagen down to the molecular level. This structure, alignment, and number of bundles give tendons their unusual tensile strength. This feature of bundles within bundles is no different than the pattern seen in support cables for suspension bridges. Interestingly, there is not a lot of vascularity (blood supply) in the tendon itself. As you can see in Fig. 1, all of these bundles are encased in an outer sheath that has synovial cells that help lubricate the tendon as it moves to and fro within the sheath. There are a number of other cells within the tendon that also help contribute to tendon structure and health called the extracellular matrix, along with mucoid and lipoid cells.
Now that we have the basic structure, let’s take a look at why the tendon begins to break down. When stress is repeatedly applied to a tendon, interesting biochemical reactions begin to occur. These reactions are very complex in nature, and for this article I will not detail all of them. What we need to know is that healthy connective tissue is made up of Type 1 collagen cells. With repeated stress, they begin to change into a different form called Type 3 collagen. This form is not as strong or as linear, and under a microscope looks much more disorganized. The mucoid and lipoid cells begin to morph and these reactions begin to thicken the tendon itself. (2)
Another very important event that takes place is called neovascularization. Small blood vessels begin to grow perpendicular to the good collagen, yet, strangely, they do not nourish the surrounding tissue. Some scientists believe they may play an important part in the pain response of tendon injury. Interstitial fluid also begins to enter the tissue causing localized edema in the tendon. Over time, these processes begin to weaken the good collagen, causing degeneration of the fibers. Scientists have given this pathology a new diagnosis…it is now called “tendonosis”, which literally means “tendon cellular injury”. (2)
With microscopic observation, one other important facet of tendon healing was also noted. It was found that the fibers go through three very distinct phases during the healing process. In the first 24 to 48 hours, an Inflammatory Phase corresponding to the initial micro-tearing of the fibers occurs. During this time, immune cells flood the area to initiate the inflammatory response that is needed for all cell healing in the body. These cells perform many functions; one of the most important is phagocytosis, which is the cleaning of the area of necrotic material by lymphatic cells. The next stage, called the Repair Phase, begins when immune growth factors IGFs and fibroblasts migrate to the site to begin collagen repair. This stage can last up to six weeks and during this time Type 3 collagen is formed. The last stage is called the Remodeling Phase, and it is characterized by the repaired collagen becoming more fibrous and linear. The excess edema and small blood vessels (neovascularization) disappear, and the tendon is ready to begin to handle its normal load. This can take up to 10 weeks. (1) The importance of understanding this timeline for tendon healing cannot be underestimated.
Total healing time for all three phases can last up to three or four months. However, in extreme chronic cases, the tendon can become calcified or proliferated by an abundance of scar tissue in which some scientists have affixed the term “tendonopathy”. Healing in these cases can take up to a year.
So, how can acupuncture help this problem? Let’s for a moment look at the traditional Chinese medicine (TCM) diagnosis of tendon pain: Stagnation of qi and Blood in the associated channel. What does this mean and how does it relate to the diagnosis of tendonosis? As stated above, we now know repetitive motion or stress on the tendon causes tendon fibers to undergo pathological changes that result in thickening and disorganization, neovascularization, edema, and, finally, degeneration of the fibers themselves. Of course, ancient Chinese practitioners didn’t know of these microscopic changes, but by observing and feeling the hardened diseased tendon, along with diminished motion of the associated joint, you can understand how ancient Chinese doctors could come to the conclusion that the qi and Blood were stagnated.
I find it fascinating that with the microscopic information we now know, the TCM diagnosis stands up quite well. This is even more apparent if we accept that when Chinese practitioners speak about blood they are probably including lymphatic and interstitial fluids. The concept of acupuncture moving the qi and Blood to assist in healing is also not without merit as numerous studies have shown acupuncture does increase vasodilatation around inserted needles, along with the anti-inflammatory molecule adenosine.
Further, a study from the University of Sao Paulo, Brazil is eye-opening. It compared electro-stimulation, laser therapy, and ultrasound therapy on the healing rate of collagen in tendon repair. Their conclusions were very interesting. Electro-stimulation clearly increased collagen repair faster than the other two modalities, although all three showed improvement over the control group in which the tendons were allowed to heal through rest alone. (3)
With this information in hand, acupuncture with electro-stimulation appears to be an excellent modality to maximize the healing of tendon fibers. When I’m discussing the benefits of acupuncture with doctors, one of the most important aspects of acupuncture therapy that I point out is that we are able to directly access the injured tissue. The fact that we are able to needle into and around the tendon itself is a big advantage, as it allows us to apply electro-stimulation directly to the tendon itself.
I use a simple four-needle technique to accomplish this. First, I needle directly into the osteotendinous and muscular junctions. This is usually exactly where the pain emanates and is confirmed with palpation. I then thread two needles along each side of the tendon with horizontal insertion. With the needles in place, we have two needles in the tendon itself and two needles running alongside the tendon. I then hook the needles up in a crossing pattern with electro-stimulation. The two needles in the tendon junctions are hooked together and the threaded needles are connected, allowing current to stimulate the entire tendon, stimulating fiber growth.
I want to emphasize again that we are talking about chronic tendon pain. Acute pain, resulting from a one-time overuse of the tendon such as painting a room or spring clipping the garden does indeed create inflammation as the fibers are traumatized through micro-tearing. However, this is considered short-term inflammation. It is only when the motion is repeated over and over that tendonosis begins to appear. I find that acute tendonitis also responds quite well to the same needle configuration that is described above.
The use of ice in the first 24 hours of initial injury also seems appropriate. However, if the pain continues, I have the patient switch to heating the area to stimulate blood flow. Of course, Chinese liniments are appropriate for both chronic and acute cases to assist in moving qi and Blood. Clinically, I always use cross-fiber massage to stimulate and break up the thickening tissue found in tendonosis as an adjunct to acupuncture therapy.
It is said that a “good Chinese doctor will try to find the root of their patient’s disease”. In most tendon cases, repetitive motion is the causation. Checking the ergonomics of a computer workstation is equally as important as checking the biomechanics of a baseball pitcher.
Last, but not least, there are a number of areas in which Chinese medicine seems to give us an advantage in preventing and treating tendonosis. Our ability to administer herbs to nourish liver blood, or to increase overall yin from a constitutional point of view could play a part in preventing tendon injury, as both acute and chronic dehydration is known to play a part in fiber degeneration in older athletes. A recent study went so far as to suggest some people might even have a genetic predisposition for tendonosis, indicating they may have a deficiency in Jing that leads to weakened tendon function. (4)
In conclusion, the studies are all in agreement that inflammation plays a very minimal role in tendon injury and pain. A tendonitis diagnosis should only be applied to a very acute condition. All chronic cases should be treated with the correct diagnosis of tendonosis, the degeneration of tendon fibers. As practitioners, it’s important to educate our patients so that they can make correct decisions in their own healing. Hopefully, those decisions include traditional Chinese medicine, which has been shown to significantly improve tendon health.
1. Tendon Injury and Tendinopathy: Healing and RepairPankaj Sharma and Nicola MaffulliJ. Bone Joint Surg. Am. 87:187-202, 2005. doi:10.2106/JBJS.D.01852. The painful nonruptured tendon: clinical aspects
Karim Khan, MD, PhD, FACSP, FACSM,
Clin Sports Med 22 (2003) 711– 725
3. Effects of laser, ultrasound and electrical stimulation on the repair of achilles tendon
injuries in rats: a comparative study
Araújo, RC.1*, Franciulli, PM.1, Assis, RO.1, Souza, RR.1 and Mochizuki, L.2
1São Judas Tadeu University – USJT, Department of Physical Therapy, 546, CEP
03166-000, Taquari, SP, Brasil
4. The COL5A1 gene and Achilles tendon pathology.