Knee cartilage is an important element of supporting-motor apparatus. The most part of loading is put on this zone of leg. Cartilage tissue is what suffers in case of traumas and injuries. The tissue becomes worn, thin, loses elasticity, and a person has different diseases developing.
Cartilage is a thin elastic tissue. Knee joints have two types of cartilage: fibrous (meniscus) and hyaline. Fibrous tissue is very robust and can resist pressure. Hyaline tissue is more elastic and can cover the surface along which the joints move. Unfortunately, hyaline tissue recovers very slowly. New formations are usually fibrous tissues of poor quality.
First and foremost, cartilage tissue has connective function: it serves to lower friction in places where bones are connected. The inner surface of the joint is covered with joint fluid that serves as lubricant. Joint fluid is important for human joints just like machine oil is important for a car.
The second function of this fluid is to provide cartilage tissue with nutrition. Since joint cartilage has almost no blood capillaries, blood hardly flows into them. Therefore, all nutrients get inside with joint fluid.
Cartilage can be destroyed as the results of influence from different factors (pretty often, several simultaneously). The most widespread negative factors leading to pathologies of cartilage tissues are:
- sedentary lifestyle, or vice versa, too much loading on a joint;
- unhealthy eating (e.g. intake of foods that has too much animal fat);
- smoking and alcohol abuse;
- poor conditions of living and working;
- lack of vitamins and minerals;
- metabolism disorders.
Besides, undercooling and poor blood flow in the joint also contribute to fast destruction of cartilage.
Complicated pathological processes make cartilage laminate and get thinner. Cartilage degradation, in its turn, makes it harder for bones to move along each other, which accelerates destruction of cartilage. When the amortizing function degrades, bones become flatter, and the surface of interconnection grows, which makes up for osteophyte and narrowing of joint space. As the result, a person develops stiffness and strong chronic pains.
When appropriate treatment is absent, and cartilage tissue and bones get severely damaged, the patient loses the ability to work, rest and move on his own normally.
First, it should be noted that cartilage tissue is fragile and is easily damaged. In order to restore patient’s ability to have normal life without pain, German specialists use modern methods of restoration of hyaline cartilage of knee joint and prophylactics of pathologies of cartilage tissue.
First, doctors resolve to non-surgical (conservative) treatment methods including medication therapy.
Cartilage protector is a modern method of restoration of cartilage tissue. As a rule, these medications contain glucosamin (it strengthens cartilage tissue and makes it more resistant to mechanic damage) and chondroitin (ensures rigidness of cartilage tissues during stretching and compression). Cartilage protectors can also be used as a preventative measure, not only to treat cartilage pathologies at early stages (when the cartilage is fully destroyed, it cannot be restored).
If you decide to use cartilage protectors, it’s crucial to be patient and follow doctor’s recommendations strictly, because such treatment can be pretty long.
Today, Germany and many other countries develop new methods of surgical restoration of cartilage tissue in knee joint.
Various methods of restoration of cartilage tissue include:
- Cartilage transplantation. There are two types of transplantation: in the first case, a sample of healthy cartilage is taken from patient’s own body and transplanted on the affected area; in second case, surgeons transplant tissue grown in a laboratory.
- sanitation of cartilage. This method presupposed endoscopic removal of catrilage damage and polishing of its surface. The method allows activating regeneration profess and ceasing further damage of cartilage.
- Use of stem cells‘ properties. The surface of cartilage is processes so that microscopic holes would form. Stem cells gather in the holes and form new cartilage then. The main disadvantage of this method is low strength of new tissue, because at early stages it contains a minor amount of cartilage corpuscle.
- Endoprosthetics is a radical method of treatment of knee joint. In some cases, the worn cartilage can be replaced, but sometimes the entire knee joint should be replaced, including its bone components.
For many years, doctors believed that the process of cartilage tissue destruction can be slowed down, but it cannot be restored. However, innovations of German specialists allow growing cartilage tissue in joints in the affected area: patient’s cells are used for that.
Growing of cartilage in knee joint starts with minimal invasion and endoscopic visualization that helps to evaluate the state of joint surface, the volume of damage, and to take cells from healthy cartilage tissue. After that, the cells are sent to a laboratory where the cartilage tissue is being grown.
The procedure of knee joint cartilage transplantation is made with a minimally invasive method and arthroscopic equipment. A surgeon makes two incisions 1-2 cm each, and injects cells via these cuts using special instruments. Arthroscopy presupposes cutting pathological areas, drilling or polishing to form young cartilage tissue. The joint is cleared to boost regeneration.
When doctors have to deal with deep damage of bones, microfracture method is applied. Special instruments are used to make small holes in the damaged zone. Thanks to this surgical manipulation, new cells get to the surface, which contributes to formation of cartilage. Autotransplantation of cartilage corpuscle is constantly being improved in Germany. Recently, АТХ 3D technology made a lot of fuss: it allows preventing the need to replace joints at early stages. In this case, spheres with special covering of cartilages cells is put in the damaged area that is processed beforehand.
The previous ATX method required some kind of transporting substance for cells not to wash away. For this purpose, doctors had to grow collagen matrix and fix it on cartilage, or they had to use patient’s periosteal coverage.
This way, spheroids provided patients with spare treatment of joint cartilage with minimal surgery risks. In this case, arthroscopic control is combined with microarthrotomy technique.
Three-dimensional transplantation of cartilage cells (autogenous matrix-induced transplantation of cartilage corpuscle) presupposes transplantation of 3D spheres of cartilage cells (spheroids) in the prepared area of defect without putting coverage off.
After that, surgery is performed with microarthrotomy technique under arthroscopic control. This method is minimally invasive, which means it guarantees spare treatment and greatly reduces the risks connected with surgery. Grow power of cartilage tissues around the defect is much higher when compared to patient’s real age.
The first stage of arthroscopic surgery (endoscopy of joint) is taking samples of patient’s cartilage tissues. Cartilage cells are taken from the sampled tissues and taken to state-of-art laboratories to be cultivated in sterile conditions.
Cartilage tissues are taken from a healthy, minimally damaged and minimally loaded joint area. Surgical invasion can be made on outpatient basis: it gets about 30 minutes. At the same time, about 120-150 ml of patient’s blood is taken. The blood is used to obtain serum in a laboratory.
Cartilage cells multiplicate in serum taken from patient’s blood. This method eliminates contact with foreign protein and helps to sustain normal conditions for cells grows at optimal level. Therefore, the risk of cartilage rejection is reduced, because doctors use patient’s own cells.
The process of cell aging takes about 3-4 weeks when small three-dimensional cartilage cell aggregates are formed. When the process of cultivation is finished, biological material is sent to a doctor. Transportation of material should be made within a few hours in certain conditions, in special cooled containers to preserve the quality of cells.
Cartilage tissues (chondrospheres) are used to fill the processed cartilage defect of joint. Cells are fixed to bone tissues, fill up the defect and eliminate it. As soon as cartilage spheroids start contacting with the defect, their connecting molecules (adhesive proteins) maintain relative mechanical instability near bone tissue during 10 minutes. After that, cartilage cells grow into the defect and fill it up.
This operation is made by minimally invasive method with arthroscopic control, and lasts for about 30-60 minutes. At the first stage, damaged cartilage tissue is removed, and patient’s aggregates of cultivated cartilage cells are put in.
The medical benefit of cartilage cell transplantation was being proved during 25 years since introduction of this method.
Patient’s body does not consider the implanted material to be a foreign body, because it has the same features as natural cartilage. Therefore, live cartilage corpuscle can build up new fully functioning cartilage layer. Due to the fact that the cartilage cells cultivated in the form of spheres (so called „spheroids“) are put directly into the damaged joint lacking cartilage tissues, cells continue developing right the place where the cartilage tissue is required. That helps to develop healthy autogenous cartilage tissue that has all protective features the damaged joint lacked.
Non-surgical methods used to fix cartilage in case of joint degeneration can only diminish painful sensations, but are not enough to restore the right joint surface.
Surgical methods, such as drilling, micro-fracture, and brain cell stimulation don’t restore glossy cartilage. In most cases, the above mentioned methods are not enough, because cartilage is replaced by fibrous cartilage that has somewhat different mechanic and elastic peculiarities than joint cartilage.
Hyalograft C is a good alternative to cartilage transplantation: it allows eliminating or reducing pain, improves movement of joint and helps patient to get back to active life and sports.
Basing on clinical examination and additional analyses, a doctor will evaluate cartilage damage and figure out a type of treatment with cultivated cells. Transplantation of autologic joint cartilage consists of two stages:
- The first stage is diagnostic arthroscopy during which the doctor defines the size, location and type of damage. He decides whether autological cartilage transplantation is possible in this case, or some other method will work better, for instance, mosaic method. If the doctor decides to perform treatment with autological cartilage transplantation, he takes a small fragment of healthy cartilage. Gathered cartilage cells (cartilage corpuscles) will be multiplied by tissue growing, then transferred to nutritional medium that consists of hyaluronic acid where they’ll continue multiplying. 5-7 weeks after the first arthroscopy, a transplant will be ready for implantation in the damaged area.
- After that, the second stage of treatment goes. It can be arthroscopy, or miniarthrotomy. This time, the transplant is put into the damaged area. After the second intervention, a patient needs to go through rehabilitation program that’s crucial for therapeutic success.
Arthroscopy is performed under local or general anesthesia. The operation requires making two small cuts about 5 mm each on the front part of knee: it makes injection of camera and operation instruments possible.
During arthroscopy, doctors gather a bit of glossy joint tissue (about 150-200 mg) from healthy surface to multiply it. The material is the size of a rice grain. After that, biopsy material is transferred to nutritional medium that is also used for transportation back to laboratory.
Tissue bioengineering is a modern innovative technique that allows reconstructing different live tissues, including joint cartilage.
After two weeks of multiplication in liquid nutritive medium, the cells are transported into a construction of hyaluronic acid where they also continue multiplying. In 2-3 weeks, Hyalograft- C sample is ready to be transferred to the damaged area.
Autologic cartilage cells are cultivated together with non-autologic proteins. During the production process, cells are washed, and a little amount of proteins can stay in the diluted material. However, there were no reports of negative outcomes connected with a small amount of these proteins.
Sampled cartilage cells are put into the medium that contains 2 antibiotics: penicillin and streptomycin. If a patient is sensitive to these antibiotics, he should inform the doctor about it. The main benefit of autological cartilage transplantation is that there’s no possibility that the transplant will be rejected by patient’s body, because transplanted cartilage corpuscles are patient’s own cells.´
During the second operation – implantation that is usually performed in 5-7 weeks after biopsy – the medium with cartilage cells (cartilage corpuscles) is taken to the damaged place. It is done by an arthroscopic method, or method of miniarthtopy.
The transplant (diluted cartilage ready for transplantation) is processed so that to obtain the size and the form of the damaged area. Thanks to its adhesiveness, the biopsy material fixes to the damaged place and fills it up. In rare cases, transplant fixation with fibrin glue is required.
The risk of complications is very low, but it may concern vessels, nerves, post-surgery infections, embolia, thrombosis, movement or loss of transplant.
When transplantation is over, the treated joint will be immobilized for 24 hours and fixed with drainage. One day after, a person will be able to make active and passive movements without load on the limb during 6-8 weeks. Additionally, intense physical therapy is used to improve movement of joints and muscles.
Patient will start in a clinic for 2-4 days. Rehabilitation course will be figured out by a physical and performed by a specialist of physical therapy. Detailed treatment plan after transplantation depends on the volume of operation and location of damage.
Full loading of joint is possible in 12 weeks only. During this period, a patient can walk and climb the stairs. In 3-6 weeks a patient can get back to easy exercises and sports – cycling, swimming. Later on, physical exercises can be improved and increased to full load, but they shouldn’t be performed during the first year after operation.
Biological regeneration of joint surface requires intense post-surgery treatment. The results of trials show that full reconstruction is possible after 12-24 months only. According to the results of clinical studies, the efficiency of transplantation in isolated damaged knee joint cartilage is about 80-85%.