Oral corticosteroid use and the risk of developing avascular necrosis: A large retrospective review

The risk of adverse events, specifically avascular necrosis (AVN), associated with corticosteroid use is not well reported. The aim of this study was to evaluate the prevalence of AVN among patients with prior oral corticosteroid administration.An institutional database query recognized 113,734 adult patients with oral corticosteroid administration between January 2006 and May 2017. A temporal query performed on this cohort determined that 789 had a diagnosis of AVN following oral corticosteroids. A retrospective review was performed on this cohort. Data collected included demographics, comorbidities, date of initial oral corticosteroid exposure, and time to diagnosis of AVN. Records without radiographic confirmation of AVN were excluded from analysis. Patients with cumulative lifetime dosages greater than 10,000 mg prednisone were excluded from analysis.A total of 789 patients with oral corticosteroid use prior to diagnosis of AVN were identified. Five hundred and seventy-two patients were excluded due to insufficient documentation of oral corticosteroid dosage, no radiographic evidence supporting the diagnosis of AVN, insufficient data confirming the temporal relationship between oral corticosteroids and AVN, and/or a cumulative dosing of >10,000 mg prednisone. This left 217 patients included in the analysis. The mean duration of use prior to diagnosis of AVN was 219 (± 374) days, and mean cumulative dose was 3314 (± 2908) mg prednisone equivalents. Mean time between diagnosis of AVN and onset of pathologic fracture was 379 (± 1046) days.For patients receiving low cumulative doses of oral corticosteroids, corticosteroids pose a small risk of development of AVN. More studies are required to better characterize risk.