Cartilage belongs to the connective and supporting tissues. It consists of cartilage cells and the intercellular substance surrounding them. Depending on the composition of this substance, a distinction is made between hyaline, elastic and fibrous cartilage.
Cartilage baldness describes the condition when there is no more cartilage. Cartilage tissue in general is very elastic in compression and bending, which is why it can be found on the one hand in parts of the body that are exposed to high pressure loads in everyday life (such as joint surfaces) and on the other hand in areas that must have a high degree of elasticity (such as the auricle and external auditory canal). In adults, cartilage tissue contains neither vessels nor nerves.
It must therefore be supplied by another route. This supply takes place by diffusion, which means that the nutrients passively migrate from their higher to their lower concentration. The joint cartilage obtains the nutrients it needs for survival from the joint mucosa (synovia).
Cartilage in other places has a so-called cartilaginous membrane (perichondrium), which performs the same function. In order to better classify cartilage damage, the classification according to Outerbridge is used, in which grades 0 to 4 are distinguished. However, it is important to note that the extent of objectively detectable changes in cartilage cannot always be exactly matched to the extent of the patient’s symptoms.
Some patients have hardly any pain at all, although severe damage has already been demonstrated, others have a very high level of suffering, although hardly anything can be determined with the help of examinations. For this reason, it is important to discuss and plan the treatment very well with the patient, since it is his or her well-being and not the X-ray image that is to be restored.
- Grade 0: no existing cartilage damage;
- Grade 1: the cartilage is completely preserved, but softens, especially under pressure;
- Grade 2: the cartilage is slightly roughened on the surface;
- Grade 3: the cartilage is torn open up to the bone, which makes it possible to find something like a crater-shaped defect in the tissue;
- Grade 4: the cartilage is completely lost down to the bone, so the bone is exposed.
Damage to articular cartilage has been described in several million people worldwide and can be attributed to a wide variety of causes.
In general, chronic triggers can be distinguished from acute ones. The most common acute cause of cartilage damage is an injury that usually occurs in the course of a sports accident or a fall. The cartilage can be damaged to a greater or lesser extent by a massive violent impact on the joint or by twisting or twisting around (this occurs particularly frequently in the ankle joint).
In most cases, this defect is limited to one area, but nevertheless, a deep tear or, in particular, the removal of small pieces of cartilage with subsequent entrapment in another part of the joint can cause considerable discomfort to those affected. The chronic cartilage damage is mostly caused by wear and tear. On the one hand, this wear occurs as part of a completely natural aging process.
The result of this process is called arthrosis (chronic degenerative joint disease). Depending on their location, the joints have to carry more or less of our body weight and are subjected to many other stresses and movements every day. The type and intensity of these strains also affects the speed of wear and tear of the cartilage tissue.
It is therefore not surprising that risk factors for cartilage damage are mainly overweight and incorrect or excessive loads such as certain sports and, of course, advanced age. Certain genetic factors also play a role. Some people simply have a poorer quality of cartilage and therefore a predisposition to develop cartilage damage faster than others, without being able to do anything about it.
In addition, malalignments and the resulting incorrect weight bearing can also promote the development of cartilage defects. Another cause of cartilage damage can be long-term immobilization of joints. Acute cartilage damage often causes severe pain, sometimes only under stress, but sometimes at rest.
In addition, the mobility in the joint is limited in many cases. In the case of cartilage damage that develops chronically, symptoms may be absent for a long period of time.Complications in this clinical picture are mainly effusions resulting from the reactive fluid retention in the joint, which become conspicuous as swelling, and arthrosis, which is almost inevitable on the basis of long-term cartilage damage. The problem with cartilage damage is also that the human body is only able to regenerate cartilage tissue to a very limited extent.
This is because this type of tissue is not supplied by nerve cells and blood vessels, which are, however, of great importance for the healing process. It is assumed that only about 4% of cartilage cells can be renewed, although this depends on age. This is not enough to be able to correct any damage that has occurred without outside help. In most cases, the damage increases over time rather than improving.