This study provides a comprehensive analysis of the global burden and socioeconomic impact of knee osteoarthritis (KOA) from 1990 to 2019, using data from the Global Burden of Disease (GBD) study. The analysis covers 201 countries and regions, focusing on prevalence, incidence, and disability-adjusted life years (DALYs) by age, sex, sociodemographic index (SDI), and income levels. Key findings include: - **Global Prevalence and Incidence**: In 2019, there were approximately 364.58 million prevalent cases of KOA (225.16 million in females), 29.51 million incident cases (17.53 million in females), and 11.53 million DALYs (7.09 million in females). The Western Pacific Region had the highest endemicity, with a prevalence of 7,319.87 cases per 100,000 people. - **Sex and Age Differences**: Females had higher prevalence, incidence, and DALY rates than males, with the highest rates observed in the 80–84 age group. The prevalence was highest in high-middle SDI countries, while incidence and DALYs were highest in middle SDI countries. - **Sociodemographic and Income Factors**: SDI was positively associated with prevalence, while income was positively related to prevalence, incidence, and DALYs. Middle-income countries had the highest rates of KOA. - **Regional and National Variations**: The United Arab Emirates showed higher prevalence, incidence, and DALY rates among males, contrary to other regions. Thailand had the highest prevalence, the Republic of Korea the highest incidence, and Japan the highest DALYs in 2019. The study highlights the significant global burden of KOA, emphasizing the need for increased awareness and targeted health policies, particularly in the Western Pacific Region and older females.This study provides a comprehensive analysis of the global burden and socioeconomic impact of knee osteoarthritis (KOA) from 1990 to 2019, using data from the Global Burden of Disease (GBD) study. The analysis covers 201 countries and regions, focusing on prevalence, incidence, and disability-adjusted life years (DALYs) by age, sex, sociodemographic index (SDI), and income levels. Key findings include: - **Global Prevalence and Incidence**: In 2019, there were approximately 364.58 million prevalent cases of KOA (225.16 million in females), 29.51 million incident cases (17.53 million in females), and 11.53 million DALYs (7.09 million in females). The Western Pacific Region had the highest endemicity, with a prevalence of 7,319.87 cases per 100,000 people. - **Sex and Age Differences**: Females had higher prevalence, incidence, and DALY rates than males, with the highest rates observed in the 80–84 age group. The prevalence was highest in high-middle SDI countries, while incidence and DALYs were highest in middle SDI countries. - **Sociodemographic and Income Factors**: SDI was positively associated with prevalence, while income was positively related to prevalence, incidence, and DALYs. Middle-income countries had the highest rates of KOA. - **Regional and National Variations**: The United Arab Emirates showed higher prevalence, incidence, and DALY rates among males, contrary to other regions. Thailand had the highest prevalence, the Republic of Korea the highest incidence, and Japan the highest DALYs in 2019. The study highlights the significant global burden of KOA, emphasizing the need for increased awareness and targeted health policies, particularly in the Western Pacific Region and older females.