Aim of study: Analysis of data on the incidence and prevalence of osteoarthritis (OA) of the hip and knee in the general population.
Method: Review of relevant investigations concerning epidemiology of hip and knee OA.
Results: Estimates of incidence and prevalence of OA of the hip and knee vary considerably among 29 studies from 14 countries and 4 ethnic groups (incidence: 10 to 2230 per 10(5) person-years, prevalence: 0.5% to 36%.
Discussion: Because of the differences in study design, study populations, and the definition of OA, a comparison between different studies is very difficult. Nevertheless, the following patterns can be identified: In general, both the incidence and prevalence of OA of the hip and knee increase with age. The sharp increase in incidence of symptomatic OA of the knee after age 50 in women suggests an influence of menopausal changes of hormonal status. The prevalence of radiographically defined OA of the hip is higher in men than in women, but a reverse pattern was found for OA of the knee, especially after age 45. The prevalence of radiographically OA was found to be higher in caucasian than non-caucasian populations at the hip but not the knee joint. Among patients with radiographically defined OA at the hip, joint pain seems to be more common in women than in men. In contrast, the frequency of joint pain in persons with radiographically defined OA of the knee is about the same in women and men.