Osteoarthritis (OA) is a chronic, prevalent, debilitating joint disease characterized by progressive cartilage degradation, subchondral bone remodeling, bone marrow lesions, meniscal damage, and synovitis. It occurs mainly in the lower extremities but also occurs in the upper extremities and the spine - spondylarthritis. Due to the increase in the average life expectancy, osteoarthritis is now a disease that affects a large part of the population. The predisposing factors for the onset and progression of the disease are the high body weight, the individual's work, previous joint injuries as well as heredity. It occurs more often in women than in men.

Symptoms of osteoarthritis are mainly pain in the joint that worsens over time, stiffness and gradual decrease in the range of motion of the joint, as well as muscular atrophy around the joint. Pain and stiffness are the cause of the limitation of physical activity and this results in the development of muscular atrophies that exacerbate existing symptoms by limiting the patient's mobility and ultimately affecting his or her psychological state. Also often occurs swelling and redness, increased local temperature of the joint and nighttime pain. The knees and hips are the most common site of the disease.

Rheumatoid arthritis is an autoimmune disease which means that the defense mechanism of the body attacks the joints and other organs of the body without having clarified until today why this happens. The eyes, skin, lungs, heart and vessels are target organs of the disease.

In the joints, the disease affects the articular cartilage, the synovial membrane and the synovial bursa causing gradual deterioration which, if not treated in time, produce severe limb deformities. Pain, redness and edema are the main symptoms of the disease which can affect many joints of the upper and lower limbs at the same time, especially the small joints of the hands. Patients with rheumatoid arthritis may also experience symptoms such as tensile fever, malaise, and severe morning stiffness.

Psoriatic arthritis is an inflammatory disease of the joints and belongs to autoimmune diseases. It also affects the ligaments and tendons around the joints and is associated with skin psoriasis. The disease begins at any age but mainly occurs at the age of 30 to 50 years. Joint disease usually occurs 10 years after the appearance of the skin symptoms. The symptoms of the disease are like those of rheumatoid arthritis. The main ones are pain, stiffness of one or more joints, pain in the small joints of the fingers which are swollen and look like sausages, gradual decrease in the range of motion of the joints, fatigue and nail changes — for example, the nail separates from the nail bed or becomes pitted, mimicking fungus infections. The cause of the disease is unknown. Heredity and stress seem to play a role.

Post-traumatic arthritis occurs and develops after an injury to the joint that is not treated promptly and properly. A fracture of the joint that affects the structure of the articular cartilage if not treated early enough to completely restore the anatomical integrity of the joint (surgical treatment of displaced intraarticular fracture), then post-traumatic arthritis occurs. Also, in the knee joint structures such as meniscus and anterior cruciate ligament should be restored as soon as possible after their injury for the same reason.

Post-traumatic arthritis can begin at any age after a severe joint injury and develops quickly if neglected. Finally, neglected articular cartilage damage at younger ages, such as osteochondritis dissecans (articular cartilage and subchondral bone damage without a clear cause), is often the cause of post-traumatic arthritis.