Joint Replacement Surgery in Patients with Rheumatoid Arthritis in South Korea: Analysis of a Large National Database.

Background: We aimed to investigate the current trend of joint replacement surgery incidence in patients with rheumatoid arthritis (RA) in South Korea and to compare the incidence of joint replacement surgery in each affected joint. Methods: We performed this big data analysis to investigate the current trend of joint replacement surgery incidence in patients with RA in South Korea and to compare the incidence of joint replacement surgery in each affected joint. This retrospective study was based on data from the Korea National Health Insurance claims database. Results: The prevalence of RA increased every year (0.13% in 2008, 0.25% in 2016). The number of newly diagnosed patients increased from 29,184 in 2010 to 38,347 in 2016. The incidence rate of joint replacement surgery in patients with RA increased from 0.72% in 2010 to 4.03% in 2016. The knee (68.3%) was the most commonly replaced joint. The relative risk (RR) of additional joint replacement surgery was highest for the shoulder joint (RR,1.454; 95% confidence interval, 0.763-2.771). The median time from diagnosis to surgery was the shortest in the elbow joint (379 days) and the longest in the shoulder joint (955 days). The median time for each joint was short in order of the elbows, ankles, hips, knees, and shoulders ( Conclusions: The most frequently and initially replaced joints were different, but the prevalence and incidence of RA, as well as those of joint replacement surgery, have recently increased in South Korea. Joint replacement surgery in RA was the highest for the knee joint. The median time from diagnosis to surgery was shortest for the elbow, followed by the ankle, hip, knee, and shoulder. Regardless of whether patients are symptomatic, evaluation of large joints such as the knee, elbow, ankle, and hip should be considered from an early stage.