Osteoarthritis is the eleventh cause of disability worldwide, and its prevalence only increases as the age and weight of population increase.
It is a complex disease, with a high level of genetic contribution (40-80%), that involves alterations of the entire joint at the level of the cartilage, bone, synovium (membrane covering the joint), ligaments, and periarticular muscles.
The most affected joints are the knee, hand, and hip, being most common in the elderly (especially women), and people with overweight and traumatic joint injuries (often work-related).
Articular cartilage is composed of tissue fluid (65-85%), type II collagen (15-22%) and a special type of proteins, the proteoglycans (4-7%).
The predominant cells of the cartilage are the chondrocytes, responsible of replacing the damaged tissue, although there are also mesenchymal stem cells, potentially useful for cell transplantation treatments.
Exercise and cartilage regeneration treatments
World Health Organization recommends at least 150 minutes of moderate physical exercise per week for adults. Thus, regular exercise of moderate intensity is important for skeletal health and one of the key treatments for osteoarthritis.
Among the other regenerative treatments for osteoarthritis are those that use mesenchymal stem cells derived from the bone marrow. They are used in the form of cell implants or injections on the joints, where they turn into chondrocytes and help to repair cartilage
Besides the treatments with stem cells there also implants of autologous chondrocytes, that can be of two different types:
- Autologous Chondrocytes Implant (or ACI): chondrocytes are taken from healthy cartilage (not subjected to heavy use), cultured, and injected in the joint.
- Matrix Autologous Chondrocytes Implant (or MAC): chondrocytes are incorporated in a matrix structure, that acts as a “scaffold”. This matrix can incorporate specific genes to increase the production of growth factors and help in restoring cartilage tissues.
- Exercise performed by donors and recipients of mesenchymal stem cells and chondrocytes improves the efficacy of the cartilage reparation treatments.
- Progressive exercise rehabilitation programs should be implemented at early stages post-transplant.
Exercise as an Adjuvant to Cartilage Regeneration Therapy. Smith JK. Int J Mol Sci. 2020 Dec 12;21(24):9471. doi: 10.3390/ijms21249471.