Articular cartilage diseases: Newer therapeutic developments

 

Articular cartilage diseases: Newer therapeutic developments

 

 

The newest therapeutic developments for articular cartilage diseases are significant and relieve the patient from pain and suffering.

Articular cartilage is a thin, soft, and elastic membrane that covers the articular surfaces of bones and allows smooth and minimal friction movement of the articular surfaces. Its primary function is the distribution of loads and the reduction of pressures on the subchondral bone (the bone below the cartilage).

It consists of water, collagen, proteoglycans, proteins, and chondrocytes. This unique composition ensures special mechanical properties: it can be deformed during loading and, after removal, regain its original shape and return to its actual thickness.

“Cartilage is not penetrated by nerves or blood vessels and is nourished by diffusion from synovial fluid. The synovial membrane produces this, and its amount in a typical joint is minimal.

The consequence of this is that articular cartilage has a limited capacity for self-healing and self-repair, with the result that when it is injured or affected by a disease (rheumatoid arthritis, septic arthritis, osteonecrosis, etc.), it leads to progressive destruction.

Suppose the initial damage to the cartilage is not diagnosed and treated in time. In that case, the chondropathy that is initially created leads to osteoarthritis", explains Mr. Dimitrios P. Dobris, Orthopedic Surgeon, Orthopedic Supervisor at the Metropolitan Hospital, P.H.D. of the University of Athens, regarding articular cartilage diseases.

Symptomatic lesions are usually 2-4 cm in size. These affect the normal function of the joint and cause pain (pain), hydrarthrosis (fluid accumulation), and stiffness, while some may block the common.

The treatment of cartilage deficits must be individualized due to the specificity of the condition.

The qualified orthopedist who will undertake the treatment should consider the patient's age, daily requirements, general state of health, compliance, location of the joint, etc.

The treatment of articular cartilage diseases

Treatment initially includes conservative means. The first recommendation made to the patient is the muscle strengthening of the affected area to determine if, with its help, the symptoms can subside or even disappear.

If the above measure does not work, the following is the administration of preparations containing components of normal articular cartilage (glucosamines, chondroitins, hyaluronic acid, collagen) by oral administration.

Next come the direct injections of hyaluronic acid, growth factors (PRPs), mesenchymal cells, and stem cells into the affected joint.

Next comes surgical solutions, which will usually solve the problem since the above measures cannot deal with, at least, the most severe cases.

Radiofrequency

This technique is applied arthroscopically and effectively achieves a uniform surface along small gross lesions, usually first-degree. However, the high intra-articular temperature associated with this method can wholly or partially destroy the articular cartilage. Temperatures above 50°C have been defined as a critical threshold for chondrocyte death. Therefore, radiofrequency devices with temperature indicators have recently been developed to monitor temperatures during arthroscopy.

Rubbing

It is an arthroscopic technique in which, in essence, mechanical cleaning is done. It was initially described as a palliative measure to avoid total knee arthroplasty in patients with early-stage osteoarthritis. It is thought that stimulation of subchondral bone can release mesenchymal cells from the bone marrow, thereby promoting the formation of new tissue.

Microfracture method

The oldest and technically least demanding solution is the arthroscopic technique of microfractures and micro-drilling, through which communication channels are opened between the injured cartilage surface and the mesenchymal cell-rich subchondral bone. The process favors the production of fibrocartilaginous tissue that "fills" the cartilage deficit.

Transplantation of osteochondral cylinders

With this technique, osteochondral cylindrical pieces taken from an area of ​​the diseased joint that is not loaded are placed in the lesion area.

The technique of implanting osteochondral cylinders is applied either arthroscopically or by open surgery, depending on the location and size of the lesion.

Autologous chondrocyte transplantation

"It is done in two stages. First, healthy cartilage is taken from a non-load-bearing surface of the joint and sent to special centers for the culture and development of autologous chondrocytes. The patient is then readmitted to the operating room, and the chondrocytes are arthroscopically implanted into the lesion. The great advantage of the method is that hyaline cartilage develops qualitatively superior to fibrocartilaginous tissue and similar to the natural one," the doctor points out.

Transplantation of prominent cartilage and osteochondral allografts

In cases where the articular cartilage lesions occupy a large surface area of ​​the joint or, at the same time, the subchondral bone is also profoundly affected. The choice is to transplant prominent cartilage or osteochondral pieces from donors (grafts).

Autologous transplantation of specially treated cultured chondrocytes on tissue collagen substrate

Modern cartilage repair techniques rely on taking healthy cartilage tissue from the patient's joint, culturing the chondrocytes isolated from the cartilage, and reimplanting them in the area of ​​the cartilage damage, where they will grow new articular cartilage.

These cells are transferred to the area of ​​damage placed on special membranes made of collagen or hyaluronic acid (scaffolds). These two operations can be done in one process, either open or arthroscopically.

Use of early stem cells (stem cells)

The doctor takes either a small amount of adipose tissue, usually from the abdominal area, or bone marrow from the patient's hip bone. The material is then sent to laboratories specialized in regenerative biotechnology, where the stem cells are isolated and then cultured for 5-6 weeks. The final product is injected into the joint, where it will develop its healing and regenerative action.

Membranes – scaffolds

These are membranes (scaffolds) on which cultured cells are placed and placed in the area of ​​damage. The membranes offer protection to the cells as a stable substrate, adhesion to the extent of ​​damage so that they are not lost in the synovial fluid, and are additionally loaded with growth factors that stimulate the cells to build new synovial cartilage.

Gene therapy

"Recently, gene therapy has found an essential field in chondrogenesis research. Gene carriers or genetically modified chondrocytes or mesenchymal cells are placed at the site of the lesion, conditioned to produce growth factors that lead to the production of new articular cartilage (chondrogenesis). But this treatment is still in the research and experimental stage and has yet to be applied in clinical trials.

From the above, it is clear that today there are several reliable solutions for a frequent problem for which, in the past, there were very few weapons in the therapeutic quiver of the orthopedist.

However, we should remember that all the described solutions are effective only if the problem is correctly diagnosed and both the patient and the treatment are selected," concludes Mr. Dobris.

                                              Mr. DIMITRIOS DOBRIS

ΑΝΑΔΗΜΟΣΙΕΥΣΗ ΑΠΟ ΤΟ ONMED.GR        25/11/2022