Osteoarthritis (OA) is a heterogeneous clinical syndrome with a different rate of progression. In the majority of patients osteoarthritis progresses very slowly, in the minority OA leads however rapidly to destruction of the cartilage with the necessity of a surgical intervention. Progression of osteoar- thritis can be evaluated from different aspects such as various subjective indicators (evaluation of pain or general status assessed by means of questionnaires), semiobjectively (clinical finding, assessment of articular function) or objectively, i.e. by imaging methods (X-ray, sonography, MR, scintigraphy by means of 99m Tc labelled biphosphonates) or using biological markers of bone and cartilage degradation. The basic method for evaluation of the progression of osteoarthritis is measurement of the joint space width. While the mean loss of cartilage in common progressing osteoarthritis of the knee and hip joints varies in different studies within the range from 0.06–0.6 mm/year, as the rapidly progressing form we classify nowadays a joint space narrowing greater than 1 mm/year. It was found that rapidly progressing OA is more frequent in advanced age groups (above 65 years), in women, in obese patients, in heavy workers, in patients with generalized OA and with frequent inflammatory irritations. The familial incidence of this disease was als o described. It is manifested more frequently in the hip joints than the knees. A common complication of the disease is osteonecrosis. Predictive factors of rapid progression are not known, the value of assessment of biochemical markers of cartilage (e.g. COMP) or the value of bone scintigraphy are contemplated. Causal treatment of rapidly progressing OA is not known. The basis of treatment are lifestyle provisions and the administration of non-steroid antiphlogistics and analgesics. Despite this therapy the patients require replacement of the affected joint within a period of several months to 2–3 years.

        Key words: rapidly progressing osteoarthritis, evaluation of progression, joint space width