Osteoarthritis (OA) is a disease of the joints, and the disease process itself affects the entire joint, including bone, cartilage and other structures surrounding the joint (ligaments and muscles). It is the result of mechanical and biological changes that disrupt normal relations in the joint, and the most common cause of this condition is damage to the functional components of the locomotor system. Genetic predisposition, developmental disorders, endocrine disorders, obesity and frequent joint trauma are some of the risk factors that contribute to the development of this condition. It can affect any joint in the body, but most often the small joints of the hands and knees, as well as the so-called bearing joints (knee and hip). The most important clinical sign is pain, which initially manifests itself during movement and loading. However, as the condition worsens, the pain can be felt even when the patient is resting. Other symptoms include crepitations in the joint, limited mobility and stiffness in the affected joint. As the surrounding muscles weaken as the disease progresses, the affected joint becomes increasingly unstable and as a result loses some of its range of motion. The pathological process of the disease begins on the surface and edges of the cartilage in the joint, where changes first occur, it loses elasticity, causes minor damage, and then deeper damage. The process then spreads and affects parts of the subchondral bone. There is something called primary arthrosis, which comes from an unknown source, and there is something called secondary arthrosis (which occurs as a result of trauma, natural anomalies, metabolic and genetic factors). Anamnesis, clinical examination of the patient and the findings of possible radiological diagnostics are what are used to establish the diagnosis of osteoarthritis. Narrowing of the joint fissure, sclerosis of the subchondral bone, cystic changes in the subchondral bone and osteophytes are the most common radiological changes in the joint. The treatment of the disease consists of a combination of non-pharmacological (physical procedures) and pharmacological (analgesics, glucocorticoids) treatment, and operative treatment of patients who have not responded favorably to other treatment methods.