Sax O, Pervaiz S, Douglas S, et al. - This research was intended to present 90-day costs, lengths of stay (LOS), readmission rates, and complication rates between patients undergoing total hip arthroplasty (THA) for osteoarthritis (OA) and osteonecrosis (ON). Researchers retrospectively examined the National Readmissions Database for primary THAs, with 90-day readmissions evaluated from index procedure. Individuals diagnosed with OA (n=1,577,991) and ON (n=55,034) were distinguished. Chi-square and t-tests were applied to record and examine costs, LOS, and any readmission within 90 days for complications. The data exhibited that individuals undergoing THA for ON incur higher readmissions-related costs and complication rates. This study’s findings demonstrate that understanding the predisposing factors for elevated complications in osteonecrosis may improve patient outcomes.