FP10.5 Chronic Oral and Intravenous Steroid Use Are Associated with Increased Risk of Avascular Necrosis of the Hip

Abstract ICLA10 - Unraveling the Failure: Diagnostic Algorithms and Why Hip Preservation Fails, Auditorium A (BMCC Level 1), October 9, 2026, 10:30 - 12:30 Introduction Avascular necrosis (AVN) results from compromised blood supply to bone and frequently progresses to arthroplasty. Although chronic steroid exposure is a well-established risk factor for AVN, the relative risk associated with different routes of steroid administration remains poorly understood. This study aims to characterize the long-term risk of hip AVN following chronic oral versus intravenous (IV) steroid exposure. Methods Patients with over 10 years of continuous follow-up were identified in a national claims database. Using CPT and ICD-10 codes, patients were stratified by chronic steroid exposure (oral, IV, or steroid-naïve), defined as at least 90 days of use. The steroid-naïve control cohort was established through random sampling of eligible individuals within the database. Individuals with prior AVN or femoral neck fractures were excluded. The primary outcome was 10-year incidence of hip AVN. Multivariable Cox proportional hazards models compared steroid exposure adjusting for age, sex, Elixhauser Comorbidity Index, alcohol use, renal failure, lupus, HIV, obesity, tobacco use, and sickle cell disease. Kaplan-Meier analysis was used to calculate 10-year cumulative incidence of total hip arthroplasty (THA) following AVN diagnosis. Results Among 1,045,935 patients with 10 years of follow-up, 378,472 were steroid-naïve, 15,875 received IV steroids, and 651,588 received oral steroids. Ten-year AVN incidence was 0.47% in controls, 0.88% in IV steroid users, and 1.22% in oral steroid users. Compared with controls, unadjusted AVN risk was significantly higher with IV (RR 1.89; 95% CI 1.60-2.25; P<0.001) and oral steroid exposure (RR 2.62; 95% CI 2.48-2.75; P<0.001). After adjusting for patient factors, both IV (HR 2.43; 95% CI 2.01-2.93; P<0.001) and oral (HR 3.02; 95% CI 2.83-3.22; P<0.001) chronic steroid exposure remained independently associated with increased risk of hip AVN. There was no significant difference in 10-year THA incidence following AVN diagnosis between IV and oral steroid users (27.1% versus 20.8%; P=0.30). Discussion Both chronic IV and oral steroid use were associated with elevated 10-year risk of hip AVN, with the greatest risk observed following oral exposure. These findings support efforts in minimizing cumulative steroid exposure and emphasize the importance of surveillance in patients receiving long-term steroids.