Arthrosis-development · Arthrosis pains · Arthrosis treatment

Arthrosis-development

Most people with arthrosis imagine that their joints are worn down, just as the brake pads on a car wear out with time.

But this is not the case at all, cartilage does not gradually “wear down”. Lubrication by the fluid in the joints is so perfect that, even at a great age, there is no wear and tear through friction. Even the joint cartilage itself shows no significant signs of aging.

Nevertheless, in cases of arthrosis there is damage to the joint cartilage. This damage is not distributed over the entire surface of the cartilage, but is found only on locally restricted areas.

It is interesting that the arthrosis almost always begins on areas of the cartilage which are subjected to less wear.

So if arthrosis is not caused by friction or load, then what is the cause?

The supply of nutrients to the cartilage is the key factor. If this is disrupted, the “inner chemistry” of the cartilage changes, it is no longer able to carry out the tasks for which it is intended and suffers damage.

In order to understand how the supply of nutrients to the cartilage can become disrupted, it is necessary to know how cartilage functions:

cartilage contains no blood vessels or lymph vessels. How, then, can nutrients reach the cartilage cells and how are waste products removed?

The answer is by diffusion via a pump mechanism. This functions as follows:

The inner membrane of the joint (inner layer of the joint capsule) is well-supplied with blood. It produces the sinovial fluid which contains all the nutrients the cartilage requires. This is released into the joint fissure and is distributed evenly over the entire joint cartilage by the movement of the joints. From here the nutrients pass into the cartilage cells by diffusion in the same way as the waste products pass from the cartilage cells into the sinovial fluid.

This process is supported largely by a pump mechanism:

Through alternating pressure and decompression on the joint cartilage caused by movement, the cartilage is first compressed and then fully saturated like a sponge. It releases waste products when under pressure and absorbs nutrients when pressure is relieved. It is clear that permanent pressure as well as permanent lack of pressure both lead to disturbances in the supply of nutrients.

Since only two points on the joint surface ever touch at any one time in a joint, this pump mechanism only takes place between these points. In order to keep the joint cartilage healthy, I need alternating pressure and decompression on each point of the joint cartilage. In simple terms this means: 

moving the joints as far as possible in every direction so that all areas of the cartilage are subjected to pressure.

However, these conditions are seldom fully met these days. Most of us sit too much or have other one-sided occupations. Many movements which are theoretically possible in our joints are never used in daily life. As a result, some areas of joint cartilage are subjected to too little alternating pressure and decompression and arthrosis therefore gradually occurs.

There is, however, another reason for the development of arthrosis, and that is muscle dysfunction. A word about this:

our body adapts to our needs, i.e. our muscles have just as much length and strength as is required for us to carry out our everyday movements.

The shortening of the muscles in particular make the muscles much more susceptible to damage. An unaccustomed movement or stumble, which demands more length from some muscle fibres than they are accustomed to, is sufficient to cause a disturbance in movement. As a reaction to such over-stretching, the body increases the tissue tension in the affected muscle fibres in order to protect these muscle fibres from tears in the actual muscle tissue itself. In certain joint positions, these “sick” muscle fibres become so tense that they force the joint into a deviation from the normal course of movement, which leads to increased shearing stress on the cartilage. And it is this shearing stress which the cartilage is able to withstand least of all.

There are, then, two mechanisms which lead to arthrosis:         

1. Limited mobility of the joints from our everyday one-sided movements and posture = areas of the joint cartilage are subjected to permanent pressure (e.g. sitting for long periods), other parts of the joint cartilage have permanent long-term decompression (e.g. the pelvic joint is never stretched to the limit).
2. Several muscle fibres in which the connective tissue is chronically tense, leading to movement causing shearing stress on the joint cartilage.

Arthrosis pains

When we speak of arthrosis pains, we usually presume that it is the damaged joint cartilage which hurts.

But cartilage itself cannot hurt, as it is not innervated i.e. it does not contain nerve fibres.

But the pain is really felt in the joint, isn't it? The cause of this, however, is not the arthrosis, the cartilage damage, but the “sick” muscle fibres described previously. That explains the frequently observed phenomenon that the cartilage damage shown on the X-ray is not in relation to the pain: patients with chronic cartilage damage who have relatively little pain and patients with little cartilage damage but severe pain.

Arthrosis pains do not depend on the degree of cartilage damage, but on the amount of sick muscle fibre.

Every movement which would cause excess strain on these sick muscle fibres is painful and the pain is located where the movement takes place, in the joint. The pain is a protective mechanism which should prevent further damage to the sick muscle fibres.

Arthrosis treatment

From the interrelationship described above, it is obvious where treatment should start:

1. The sick muscle fibres must be located and normal function restored.
2. The mobility of the joints must be restored.
3. Compensatory exercises must be found which include those movements which are lacking in everyday life, if reoccurrence of the pain is to be prevented.

Once that has happened, the joint cartilage can recover and the arthrosis be halted.