Radiographic osteoarthritis in the elderly population of Zagreb: Distribution, correlates, and the pattern of joint involvement

Aim. To determine the prevalence of radiographic osteoarthritis on five joi nt groups in an urban population sample of 306 women and 304 men over the a ge of 45 and to assess the influence of some risk factors on osteoarthritis . The validity of concept of generalized osteoarthritis was also examined b y analyzing the association of osteoarthritis on different joint sites. Methods. Radiographs of both hands, both knees, and the right hip were take n. Osteoarthritic changes on distal interphalangeal, proximal interphalange al, first carpometacarpal joints, knees, and hip were graded according to t he Kellgren-Lawrence scale. The association among osteoarthritis on differe nt joint sites was analyzed using logistic regression. Subjects were tested for age, duration of postmenopause, anthropometric measures, blood pressur e, and smoking as risk factors for osteoarthritis. Results. Hip was the most frequent site of osteoarthritis in men (27.3%), w hereas distal interphalangeal joints predominated in women (43.5%). Polyart icular osteoarthritis (greater than or equal to 3 joints) was present in 10 .8% women and 5.9% men. There was a significant influence of age on single joint osteoarthritis, but not on multiple joint involvement. Obesity was si gnificantly correlated with knee osteoarthritis in women and with osteoarth ritis on distal interphalangeal joints in men. Conclusions. In our population sample, the prevalence of knee osteoarthriti s was lower and the prevalence of hip osteoarthritis higher than reported f or most of other populations. The tendency towards polyarticular osteoarthr itis that is more common than would be expected by age, suggests a subset o f generalized osteoarthritis.