Cartilage injury
Acute care & follow-up treatment
ÜBERSICHT
Do you have cartilage damage? Cause - diagnosis - state-of-the-art therapy
The articular cartilage covers the surfaces of the bones in the knee joint and acts as a shock absorber and protective layer for the bones. This smooth but also elastic protective layer ensures smooth movement even under the heaviest loads. After damage to the cartilage, the body is generally unable to regenerate the damage. This is due to the poor blood supply to the cartilage. This results in pain and swelling, especially under stress.
Causes
The causes of cartilage damage can be divided into 2 main groups: Acute injuries during sport, at work or in everyday life. These can occur in isolation or as a concomitant injury, e.g. a torn cruciate ligament, a dislocated kneecap or an ankle sprain. The second group of cartilage damage is chronic wear and tear of the cartilage. These often occur due to excessive one-sided loading of a joint section. Axial misalignments (knock-knee, bow-leg) that have existed for a long time, as well as acquired instabilities (e.g. untreated cruciate ligament injury, loss of the meniscus, chronic dislocation of the kneecap, etc.) can lead to chronic incorrect loading, which ultimately results in a cartilage defect.
Symptoms of cartilage damage
Immediately after a trauma, a knee joint effusion usually occurs, although this can also be caused by the accompanying injuries. If a fragment has become completely detached (articular mouse), this can lead to blockages and movement restrictions (extension inhibition) in the joint. Chronic degenerative cartilage changes are characterized by recurrent irritation of the joint, as well as axial misalignments which can increase over time.
Diagnosis of cartilage damage
Irritation effusions as well as a Baker’s cyst (cyst in the hollow of the knee) can be an initial indication of cartilage damage. During the clinical examination, cartilage damage can be detected by “cracking” and “crunching” (crepitations) as an indication of a perforated cartilage surface.
An X-ray can document axial misalignment in the chronic course and provide an indirect indication of cartilage damage.
The method of choice for cartilage diagnostics is magnetic resonance imaging (MRI), which directly reveals the extent of cartilage damage.
A distinction is made between four degrees of severity of cartilage damage:
- Grade 1: Softening of the cartilage
- Grade 2: Roughening of the cartilage surface (< 50% of the cartilage surface)
- Grade 3: Crater-shaped defect of the cartilage (> 50% of the cartilage surface)
- Grade 4: Absence of the entire cartilage layer down to the bone
Treatment of cartilage damage
Treatment of cartilage damage
Mobility can be improved with physiotherapy exercises and movement exercises and swelling can be reduced with cold applications. The application of the different methods depends on the severity of the cartilage damage, the localization (stress zone?), the size of the damage and the patient’s age.
Infiltrations
There is no actual injection to build up cartilage. However, a kind of sealing effect of the existing damage can occur.
Hyaluronic acid infiltrations primarily have an analgesic and anti-inflammatory effect, but are also intended to improve the lubricity of the synovial fluid. In degeneratively altered joints, the percentage of the joint’s own hyaluronic acid is reduced, which is why chronically altered joint cartilage in particular benefits from the positive properties of hyaluronic acid infiltration.
ACP (autologous plasma therapy): As well as being used for chronic overuse syndromes, particularly of the tendon insertions, ACP infiltration is effective for mild to moderate cartilage damage by creating a kind of sealing effect. Platelets, growth factors and stem cells are concentrated in the body’s own (autologous) blood plasma. It is therefore an endogenous, biological procedure without additives.
Cartilage smoothing
This arthoroscopic procedure (keyhole technique) involves the minimally invasive removal of loose cartilage. It may be necessary to remove pieces of cartilage that have already become loose (articular mouse). This cartilage smoothing reduces friction, particularly under load, and slows down the otherwise progressive wear and tear.
Microfracturing - nanofracturing
In the case of minor but profound cartilage damage, which extends to the entire thickness of the cartilage, the exposed bone can be drilled with multiple holes. Blood and stem cells emerge from the bone marrow and form replacement cartilage. This is inferior to the original hyaline cartilage, but provides a sufficiently stable layer that offers good long-term results.
Cartilage-bone transplantation (OATS)
Cartilage regeneration therapy requires a sufficiently stable layer of bone beneath the defect. If the damage is small and localized and extends into the underlying bone, bone-cartilage transplantation is a good method of closing the defect. A bone-cartilage cylinder is taken from a non-loaded area of the joint and pressed into the defect.
Cartilage cell transplantation
Cartilage cell transplantation is the treatment of choice for major cartilage damage. It is a two-stage cartilage therapy in which two pieces of cartilage the size of a grain of rice are removed from a non-loaded area of the joint cartilage in an initial procedure (arthroscopy). The cartilage cells are then cultivated in an external laboratory for approx. 4-6 weeks before being inserted into the defect during a second procedure.
The advantage of this method is that the resulting cartilage layer most closely resembles the original hyaline cartilage. One disadvantage is certainly that two operations are necessary.
Cell-free matrix transplantation
Here, the body’s own stem cells are collected from the bone marrow under a biological matrix and cultivated by drilling holes in the bone. Here too, a cartilage replacement tissue is formed which is described as “hyaline-like” (similar to the original cartilage). The main advantage over cartilage cell cultivation (cartilage cell transplantation) is that only one operation is necessary.
In any surgical attempt to treat cartilage damage, the following factors are of paramount importance:
- The leg axis
- The meniscus status
- A ligament-stable joint
If the buffer function of the meniscus is missing in the event of major meniscus damage, the pressure conditions in this joint section increase significantly and the replacement cartilage cannot heal sufficiently. The same applies to a pronounced axial misalignment of the leg, which again leads to a considerable increase in the load on the cartilage regenerate and this has no chance to heal. Finally, the ligamentous apparatus must also be clarified, as instability (e.g. cruciate ligament rupture) causes atypical shear forces on the joint section, which also hinder the healing of replacement cartilage.
