Cartilage damage in the knee is quite common. Mostly the damage here is caused by wear and tear. On the one hand, this wear and tear occurs as part of a completely natural aging process.
The result of this process is called arthrosis (chronic degenerative joint disease). The knee joint has to carry almost our entire body weight and is subjected to many other stresses and movements every day. It is therefore not surprising that risk factors for cartilage damage in the knee are primarily overweight and incorrect or excessive stress on the knee joint, such as certain sports, and of course advanced age.
From the age of 70 onwards, almost everyone can be found to have more or less pronounced osteoarthritis of the knee joint. In addition, defective positions in the knee, such as knock-knees or bow legs, can also cause increased wear and tear of the cartilage. More rarely, injuries such as torn inner ligaments or cruciate ligaments are at the beginning of a process that ultimately results in damage to the cartilage in the knee. Cartilage baldness describes the condition when there is no cartilage left.
Diagnosis
The diagnosis of osteoarthritis offers the physician quite classic changes, which are particularly well visible in the X-ray image. The joint space is narrowed because the cartilage is worn out. As a reaction to this, the surrounding bone is hardened and in some cases new bone parts form to increase the contact surface, thus attempting to absorb the increased pressure caused by the missing cartilage in this way.
In order to better classify cartilage damage to the knee joint or cartilage damage behind the patella, we use the Outerbridge classification, which differentiates between grades 0 to 4. (see below) However, the extent of the patient’s complaints does not always have to be directly related to the extent of the changes in the joint, which is why it is always important not to rely solely on imaging but to conduct an extensive anamnesis with the patient. However, cartilage damage to the knee can only be assessed inadequately by X-ray.
The best method of examining cartilage damage is the MRI of the knee. The MRI of the knee is an examination method that, in addition to cartilage damage, can also show damage to the meniscus (inner and outer meniscus), as well as damage to the posterior and anterior cruciate ligament over time.
- Grade 0: no existing cartilage damage;
- Grade 1: the cartilage is completely preserved, but softens under pressure;
- Grade 2: the cartilage is a little bit separated on the surface;
- Grade 3: the cartilage is torn up to the bone;
- Grade 4: the cartilage is completely lost down to the bone, so the bone is exposed.
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