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(Gelenkabnützung, joint deformity)

If due to degenerative cartilage decomposition processes the articular cartilage lining gets so damaged that the natural adaptation and repair mechanisms are exhausted, there is a decompensation (decay) of the whole joint.<br></br>There is more and more cartilage abrasion, and soon bare bones show without any cartilage covering ("Moon" - lunar landscape). As a result, it then comes to bone abrasion.<br></br>As a defensive mechanism the joint now tries to enlarge the lost or even destroyed surface of pressure assimilation by growing bones again (by osteophytes - spurs).<br></br>These osteophytes usually do not fulfill their "job", on the contrary, they continue to interfere with the biomechanics of the joint only.<br></br>Depending on its severity, osteoarthritis is primarily characterized by reduced capacity, pain during exercise and rest, and heated swelling and joint stiffening.<br></br>Typical is also the strong change in the appearance of symptoms: phases with relative freedom from symptoms changing to acute inflammatory episodes (activated osteoarthritis).

The causes of arthritis are extremely varied:

Family problem, excessive weight, constant overload, misalignment of the axis of the leg, rheumatic and other inflammatory diseases, accidents, which affect the joint, hormonal, and unknown factors should be mentioned.


Treatment principle

If the many possibilities of conservative therapy do not produce the desired success, the arthroscopic joint debridement (stage 3) is carried out.<br></br>As in the treatment of cartilage damage, the goal in osteoarthritis treatment is to create a stimulus reduction (inflammation) in the joints and stimulate reparation processes.<br></br>The removal of torn meniscus parts, dead pieces of articular cartilage, cartilage abrasion material, and inflamed synovial membrane parts (partial synovectomy) leads to stimulus reduction and anti-inflammatory effects. The removal of an excessively grown amount of bone strips and bone spurs (osteophytes) reduces the abrasion.

The aim of arthroscopic treatment of osteoarthritis and the osteotomy is to prevent the onset of the unwanted artificial joint by preserving the own knee or postpone it at least as much as possible.<br></br>Natural reparation processes can be stimulated by the so-called abrasion. The abrasion is a milling up of exposed cartilage-free bone (lunar landscape).<br></br>Only the top dead border lamella (about 2 mm) is milled to uncover blood vessels. The stability and carrying capacity of the joint are not reduced thereby. By exposing the blood vessels, the growth of a replacement cartilage is stimulated.

Micro fracture: This is a technique with the same goal, in which a kind of "ice pick" is used to cut open the upper layer of bones, thus stimulating the body's own regeneration processes.

The growth of cartilage takes about two to three months, full curing and maturation however takes about a year, after which the replacement cartilage is somewhat able to take over the characteristics and functions of the natural articular cartilage. It remains, however, as a replacement cartilage (fibrocartilage), not a hyaline cartilage. Mostly a successful conversion to the hyaline or hyaline-like cartilage does not take place, so that the replacement cartilage falls victim to a more or less rapid abrasion.

The dead and exposed bone layer is removed by abrasion to stimulate the body's own recovery processes.


1. Debridement (cleaning and smoothening of the sliding surface) without abrasion:

Immediately after surgery decongestant actions, therapeutic exercises to increase muscle strength and passive movement and flexion of the leg on the motorized knee splint CPM are done. Walking is possible after the surgery, preventive care for four to six weeks.

2. Debridement with abrasion or micro fracture:

This therapy requires a consistent rest of the operated knee joint for four to six weeks depending on the defect size (two forearm crutches) and partial use for another 2 weeks (a forearm crutch support). The motto for the abrasion is: Move (stimulating the growth of cartilage replacement), but do not strain, because too early pressure on the abraded cartilage surface would destroy the cartilage replacement. The postoperative therapeutic exercise must therefore be carried out carefully and in avoidance of pain and swelling. Usually a rapid recovery can not be expected, the healing process depending on the extent of abrasion takes from six months to a year.
Should a stronger axis deviation as in terms of an O or X-leg present itself, coupled with the persistence of the complaints, so an axis correction may be necessary (see section osteotomy).

Ability to work

For office activities a sick leave period of about three weeks must be expected, provided that the patient can continue his work with two forearm crutches.
Depending on whether a debridement was performed with or without abrasion, hard physical work, if at all, will be continued only after a period of six months to a year.

Sports Ability

Swimming and cycling are usually undertaken after two or three months. Other sports must always be discussed beforehand with us. What is needed is a proper muscle function.


Compared to the initial depressing situation, the abrasion arthroplasty (as the full name of this operation) can achieve amazing results. About a year after the surgery 80 percent of patients reported a significant relief from pain and an threefold increase in their personal walking distance.

The proportion of patients requiring subsequent axis correction of the knee joint (osteotomy) is at 10 percent.


The abrasion arthroplasty has, since the introduction of the new methods for the repair of cartilage damage and osteoarthritis described below, fallen in disgrace – which I consider an injustice. It is true that they can only produce replacement cartilage, which can wear out early again - but not necessarily! Again and again we see amazing long-term success with this procedure. In addition, there is a lack of long-term experience with the new methods, and the medium-term results have not met our expectations, and they are not affordable for everyone.

New methods of surgical treatment of osteoarthritis, treatment of cartilage defects

These methods were initially developed to close small, but comprehensive cartilage thickness defects (for example, after an accident), just as a patch can. There were young patients with otherwise perfectly healthy knees. Through the cartilage healing it was sought to avoid later osteoarthritis (abrasion).

Later increasing defects were treated and also abraded knee joints (osteoarthritis). The high expectations for arthritis treatment were not satisfied, however, as it is not just a cartilage disease, but also a disease of the bone underneath the cartilage. (A turf would not grow in the desert).

So one has to transplant not only cartilage but also the bone, as can be done with the mosaicplasty. But this method can also have significant disadvantages.

Very promising is method 3 in which a collagen fleece closes the defect. Here, stem cells migrate into this matrix framework from the bone marrow, and it actually results in cartilage healing - see below Method 3

Method 1: Transplantation own cartilage-bone parts (mosaicplasty)

Using a round punch, cartilage-bone-cylinders are unloaded and removed from hardly needed knee areas and transplanted into the damaged load zone.

Advantages: Only need one surgery, low costs.

Cons: As the cartilage-bone pieces are round, only replacement cartilage grows again in the gaps, the roundness of the femoral condyle can not be reproduced perfectly with the tesserae - and the worst is - it causes small steps (hence no friction-free sliding of the joint surface)!, the cylinder may break under circumstances, or may not heal, and where the cylinder was removed, there may still be a gap. Technically a relatively difficult operation. Very limited size extent - not suitable for very large defects.

Achievements: In the medium-term up to eighty percent of patients are satisfied.

Bottom line: we use this method only in exceptional cases.


Method 2: Autologous chondrocyte implantation (ACI)

In this method, the patient's own, often bred and increased cartilage cells are introduced into the cartilage defect or even a point abraded by arthritis.

Two operations are needed: During the first arthroscopy a rice grain-sized portion of cartilage is removed, the cartilage defect cleaned and measured, and any additional damage to the joint (for example, meniscus lesion) restored.

The cartilage cells are then cultivated in a specialized laboratory and propagated.

In a second operation, this newfound cartilage is glued into the defect, using a collagen fleece tailored exactly to the size and shape of the defect, and staffed by the patient's own cartilage cells (chondrocytes). They modify the fleece to the body's own original cartilage.

This will not be done arthroscopically, as the knee joint must be opened more or less according to the size of the defect. In addition, as part of this second procedure, axis errors or instabilities must be repaired, otherwise the new cartilage lining would not take a long time before getting damaged.

Advantages: The operation comes very close to reaching the goal of healing damaged cartilage, very close! It is technically a very complicated surgery, however, there is no step-forming with the existing healthy cartilage, and the cartilage defect can be filled completely. Any kind of bending of the sliding surface can be reconstructed. The patients are pain-free soon after surgery.

Cons: Two operations are necessary, lack of credible long-term results.

Bottom line: One has expected a lot from this method. Though we have many satisfied patients whose surgery was many years ago (over 10 years), we do not use this method anymore because it is

1. tery expensive

2. very complicated

3. the expectations have not often been met

The method of choice is the

Method 3 - Three-layer, special collagen fleece

This new method also involves an insertion of a collagen fleece into the cartilage defect, but it is a very special 3-layer collagen fleece, which has very special properties. The progress of this is that only one operation is necessary and that the fleece can be very well put in a prepared bed, because it has a very good water-binding capacity. It swells in an aqueous medium and solidifies itself therefore with the surroundings. The previously required, very elaborate attachment of the graft (with fine sutures or fibrin glue) is therefore avoided. It can also bridge any larger cartilage defect step-free and can produce any curvature.

Another advantage is that not only the cartilage is replaced, but also the diseased bone parts underlying the bone, namely the so-called subchondral lamella.

The speciality of this method is that the collagen matrix (the fleece) stimulates stem cells in the bone marrow and moves them to immigrate to the fleece and to distinguish themselves:
In the lower layer the bone is formed (ie, the subchondral lamella) and in the upper layer cartilage is formed. So cartilage defects, also of considerable size, are closed with autologous (patient's own) cartilage. The collagen matrix is ​​used as a backbone and head and is completely removed after the cartilage healing. Osteoarthritis can still not be cured, but only focal cartilage defects.

The cartilage defect is completely covered by a collagen fleece

After-treatment: Up to six weeks of rest with two forearm crutches. Therapeutic exercise, motor splint, muscle strengthening.

Conclusion: The method is only a few years old. The implantation of a collagen carrier, filled with the patient's own stem cells enables probably the complete healing of the previously considered incurable cartilage damage!

A successful operation thus succeeds to cure cartilage damage in a not very much arthritis-affected knee (or any other joint), the arthritis progresses no further, or it not even arises! This can apparently minimize the need for implantation of an artificial joint or even avoid it altogether - which in turn goes with our philosophy of the greatest possible preservation of our own joints.

Full cartilage defect on patella plain
The patient feels pain at low load and even while resting.

Eighteen months after the cartilage repair the defect is completely filled and the patient is pain-free and fully capable of engaging in sports.

The complications rate is not different from that in cartilage surgery.
For some patients a "post-processing" is necessary a few months after the procedure because the replacement cartilage lining has not reached the necessary thickness and quality at all points .

More information about the new opportunity to heal cartilage defects:

Cartilage repair (pdf) (pdf)

Severe cartilage damage to the patella in an MRI representation

With a tweezer the bone can be reached, the cartilage layer is severely damaged

After cleaning, removal of dead cartilage and replacement of the kneecap back surface with new cartilage