Prevalence of Rapidly Progressive Osteoarthritis of the Hip Following Intra-Articular Steroid Injections.

Introduction: Numerous studies have indicated that intra-articular steroid injections to the hip are beneficial for short-term pain relief. However, recent studies have drawn concerns of rapidly progressive osteoarthritis of the hip (RPOH) following intra-articular steroid injections. The prevalence of RPOH following intra-articular steroid injections varies widely in the literature. Objective: To identify the prevalence of RPOH following intra-articular steroid injections, and to compare baseline characteristics between patients with and without RPOH. Design: Case series. Setting: Tertiary academic hospital. Patients: A total of 924 patients (median [interquartile range; IQR] age: 59 [45-70] years; 579 female) who received an intra-articular hip steroid/anesthetic injection from January 2016 to March 2018 and had available pre- and post-injection imaging (prior to surgical intervention) were included in the study. Interventions: Baseline and injection-related data-including demographics, age, body mass index, medical history, laterality, and steroid type-were collected from electronic medical records. Main Outcome Measures: Post-injection RPOH was determined via imaging review by a physiatry fellow, followed by an attending physiatrist and a musculoskeletal radiologist to confirm findings. Results: The majority of patients received unilateral injections into the hip, and the most common steroids used were triamcinolone and methylprednisolone. Review of pre- and post-injection imaging revealed 26 cases of RPOH, for an overall prevalence of 2.8% (95% confidence interval [CI] 1.9%-4.1%). Compared to those without RPOH, patients with RPOH were significantly older (median age [IQR]: 64 [60-73] vs. 59 [44-70] years, p = .003) and had a shorter duration of symptoms prior to their injections (median [IQR]: 3 vs. 12 [6-36] months, p <.001). Adjusted regression analyses showed that age was associated with greater odds of RPOH (odds ratio [OR], 95% CI: 1.04, 1.01 to 1.07; p = .003). Conclusions: The prevalence of RPOH following intra-articular steroid injections into the hip was lower than previously reported but still clinically relevant. This should be considered when counseling patients prior to intra-articular hip steroid injections.