The Tendinosis Injury

[Guest guest]

I thought this might interest some.

http://www.tendinosis.org/injury.html

.... Normal tendons and ligaments consist mostly of Type I collagen, with

smaller amounts of Type III collagen. When you get tendinosis, some of your

collagen is injured and breaks down. Your body tries to heal the tendon, but

when you have chronic tendinosis your body doesn't repair the collagen

properly.

Usually you can't see the tendinosis injury from the outside of the body;

swelling, heat, and redness are symptoms of an acute injury, not a chronic

tendinosis injury. However, the tissue often looks different to the naked

eye during surgery, with tendinosis showing up as tendon that looks dull,

slightly brown, and soft instead of white, glistening, and firm. Researchers

have analyzed samples of tendons and ligaments under the microscope to

discover the abnormalities that occur on a cellular scale in overuse

injuries.

Research has shown that chronic overuse injuries such as tendinosis

(including Achilles, rotator cuff, lateral and medial elbow, posterior

tibial, digital flexor, and patellar), as well as carpal tunnel syndrome and

even TMJ disorders are associated with a failed healing response in which

the body's fibroblasts produce abnormal tendon and ligament

collagen.[1,4,5,6,7,8,9,13,14,18,40,42] The composition and structure of the

collagen is abnormal compared to uninjured tendon and ligament tissue. The

following differences have been observed:

* The total amount of collagen is decreased (since breakdown exceeds

repair).

* The amounts of proteoglycans and glycosaminoglycans are increased

(possibly in response to increased compressive forces associated with the

repetitive motion).

* The ratio of Type III to Type I collagen is abnormally high.

* The normal parallel bundled fiber structure is disturbed; the

continuity of the collagen is lost with disorganized fiber structure and

evidence of both collagen repair and collagen degeneration.

* Microtears and collagen fiber separations are seen. Many of the

collagen fibers are thin, fragile, and separated from each other.

* The number of fibroblast cells is increased; the tenocytes look

different, with a more blast-like morphology (the cells look thicker, less

linear). These differences show that the cells are actively trying to repair

the tissue.

* The vascularity is increased.

* Inflammatory cells are usually not seen in the tendon but sometimes are

seen in the synovium and peritendinous structures (the areas around the

tendon).

* Electronic microscopic observations have shown alterations in the size

and shape of mitochondria in the nuclei of the tenocytes.

.... The tendinosis cycle begins when breakdown exceeds repair. Repetitive

motion causes microinjuries that accumulate with time. Collagen breaks down

and the tendon tries to repair itself, but the cells produce new collagen

with an abnormal structure and composition.

The new collagen has an abnormally high Type III/Type I ratio. Experiments

show that the excess Type III collagen at the expense of Type I collagen

weakens the tendon, making it prone to further injury. Part of the problem

is that the new collagen fibers are less organized into the normal parallel

structure, making the tendon less able to withstand tensile stress along the

direction of the tendon.

Therefore, tendinosis is a slow accumulation of little injuries that are not

repaired properly and leave the tendon vulnerable to yet more injury. This

failed healing process is the reason many people with tendinosis don't

completely heal from it and can't go back to their previous level of

activity. Once the tendinosis cycle starts, the tendon rarely heals back to

its pre-injury state.

.... The source of pain from tendinosis is controversial. At first, doctors

labeled chronic tendon injuries as " tendinitis " and attributed the pain to

inflammation. Later, doctors discovered that inflammatory cells were rarely

seen in microscope slides of chronic tendon injuries. Therefore, many

doctors have switched to the term " tendinosis " and have started to develop

alternative theories about the source of pain.

The pain from tendinosis probably comes partly from the physical injury

itself (separation of collagen fibers and mechanical disruption of tissue)

and partly from irritating non-inflammatory biochemical substances that are

produced as part of the injury process. The biochemical substances probably

irritate the pain receptors in the tendon and surrounding area. NSAIDs and

cortisone injections might reduce the pain of tendinosis by reducing or

blocking these biochemical substances, rather than by reducing

inflammation....

Some people find that when the tendinosis in their wrists has an especially

bad flare-up, they experience tingling or numbness in some fingers (carpal

tunnel symptoms). The old explanation for the numbness was that severe

flare-ups cause inflammation that presses on the nerves to the fingers and

causes numbness. When the flare-up subsides, the numbness goes away. The

newer theory is that the tendinosis injury causes thickening of the tendons

in the wrists (partly from higher water content associated with the higher

proteoglycan content), and this thickening can cause pressure on nerves to

the fingers. Despite the larger cross-sectional area, tendons with

tendinosis are still weaker than healthy tendons because of the structural

abnormalities described in the previous sections. In addition to thickening

of the tendon, inflammation of the tendon sheath can also put pressure on

nerves to the fingers. Although the tendons and ligaments themselves don't

usually show inflammation, the surrounding tissue sometimes does. ...

[Guest guest]

> I thought this might interest some.

>

>

> http://www.tendinosis.org/injury.html

Very much interested in this article - fascinating reading. Thanks

for posting it.

I was particularly interested in the conditions that were listed,

rotator cuff, lateral and medial elbow, tibial, patellar, and carpal

tunnel, because these are areas that I have had a fair degree of

success with using energy to treat pain symptoms. I printed it off

and will be digesting it more thoroughly.

Thanks again.

[Guest guest]

> I thought this might interest some.

>

>

> http://www.tendinosis.org/injury.html

Very much interested in this article - fascinating reading. Thanks

for posting it.

I was particularly interested in the conditions that were listed,

rotator cuff, lateral and medial elbow, tibial, patellar, and carpal

tunnel, because these are areas that I have had a fair degree of

success with using energy to treat pain symptoms. I printed it off

and will be digesting it more thoroughly.

Thanks again.