ABSTRACT
The incidence rate of OA is relatively low before age 50 but rises sharply and continues to increase steadily with advancing age. The age-and sex-standardized incident rates for symptomatic knee OA is estimated to be 240 cases per 100,000 person years. For hand OA, the rate is 100 per 100,000 and for hip 88.34
OA affects about 13.9% of adults age 25 and older and 33.6% of those over 65.24 Radiographic (RG) prevalence is higher than symptomatic prevalence. Symptomatic prevalence of knee OA is 16% in adults over 45 years. The prevalence of hand OA is 8% in those over 60. Hip OA prevalence is 4.4% in adults over 55. Foot OA prevalence is 2.0% in those aged 15-74 years. The prevalence of ankle OA is about 1%.52 Glenohumeral OA is much less common, but prevalence data are limited; in a general orthopedic patient population, the RG prevalence was 0.4%.31 Acromioclavicular (AC) joint osteophytes have been found to be present on 28.9% of skeletons of persons over 15 years of age, but the prevalence of symptomatic AC joint OA is unclear.27 Isolated OA of the elbows and wrists is very uncommon.
