Vakharia RM, Ehiorobo JO, Sodhi N, et al. - As there are limited well-powered studies examining the correlation of emergency department visits and total knee arthroplasty (TKA), researchers conducted this study with the following specific aims: 1) compare patients who did and did not have an ED visit with respect to their demographics; 2) identify leading reasons for the visits; and 3) determine risk-factors for ED visits (pre-arthroplasty/post-arthroplasty). Querying a nationwide database, they identified 1,364,655 patients undergoing primary TKA who did (n = 5,689) and did not have (n = 1,358,966) an ED visit within 90-days following their index procedure. Patients who did have ED visits differed from those who did not have ED visits with respect to age and mean Elixhauser Comorbidity Index scores (9 vs 6). The most common reason for ED visits was musculoskeletal etiologies. The greatest contributor to ED visits, pre-and post-arthroplasty, was hypertension. Following comorbid conditions were noted to be linked with ED visits postarthroplasty: peripheral vascular disease, coagulopathy, and rheumatoid arthritis. These findings can aid in identifying targets for quality improvement to potentially lower the incidence of ED visits following primary TKA.