Introduction:
This study aimed to analyze the epidemiological trends and burden of osteoarthritis (OA) in the United States (U.S.) from 1990 to 2021 using data from the Global Burden of Disease (GBD) 2021 study, with a focus on sex, age, and geographic disparities.

Material and methods:
We used GBD 2021 data to examine OA incidence, prevalence, years lived with disability (YLDs), and age-standardized rates in the U.S., by gender, age group, and different states. Decomposition analysis was performed to assess contributions from population growth, aging, and epidemiological changes.

Results:
Between 1990 and 2021, OA incidence and prevalence in the U.S. increased by 80.3% and 90.3%, respectively. Females consistently exhibited a higher burden than males, with the highest incidence rate in the 55–59 age group. Geographically, California had the highest absolute case numbers, while Pennsylvania showed the highest age-standardized rates. Knee OA contributed most to disability, though hand OA dominated in the oldest populations. Decomposition analysis revealed that population growth (67.55%) was the primary driver of rising OA incidence.

Conclusions:
The OA burden in the U.S. has risen substantially over the past three decades, with marked disparities by sex, age, and region. Targeted public health strategies addressing prevention, early detection, and equitable healthcare access are urgently needed to mitigate this growing challenge.