Radiographically defined osteoarthritis of the hand and knee in young and middle-aged African American and Caucasian women

Osteoarthritis (OA) has been characterized as a slowly evolving degenerativ e disease affecting cartilage and bone, with a multifactorial etiology that may differ depending on the joint site. Because OA has been considered a d isease of the elderly, few population-based studies have examined its frequ ency and characteristics in persons under the age of 45. Objective In this cross-sectional study, we examined X-rays of both knees a nd the dominant hand in a population of younger black and white pre- and pe rimenopausal women in southeastern Michigan (N=1053) for evidence of osteoa rthritis, and reported these outcomes according to the risk factors of age, body size, injury, and smoking behavior. Design: Sixteen joints of the dominant hand as well as both knee joints (we ight bearing) were evaluated using the Kellgren and Lawrence Atlas of Stand ard Radiographs of Arthritis. Results: By age 40, radiographically-defined osteoarthritis emerges in both the hands and knees. These age characteristics are observed in both black and white women, however prevalence of knee OA was higher in black females (23.1%) compared with white females (8.5%), and although prevalence of hand OA was more comparable between black (25.5%) and white females (19.2%), th e joint sites affected differed. The major risk factors reported in studies of older populations are present in this younger population where OA is ne wly emerging. Conclusions: This study provides strong evidence that primary prevention of OA must be implemented in young adulthood to curtail the emergence of radi ographically-defined OA at the mid-life. (C) 2000 OsteoArthritis Research S ociety International.