A Contemporary Analysis of Corticosteroid Injections in Patients with Mild, Moderate, and Severe Hip Osteoarthritis: High Risk, Low Reward.

Abstract

Background: Hip osteoarthritis (HOA) represents a leading cause of disability in the United States. Consequently, intraarticular corticosteroid injections (lACSIs) are routinely recommended and utilized for non-surgical management of symptomatic HOA. While they are shown to decrease pain intensity, few studies have reported on the potential risk of rapidly progressive osteoarthritis (RPOA). This study aimed to assess the rate of HOA progression following IACSI in patients with mild, moderate, and severe HOA.

Methods: This single-institution study retrospectively reviewed patients who underwent image-guided IACSI for HOA between January 1, 2022 and January 1, 2023, with a minimum follow-up of two years. Pre-injection and post-injection radiographs were reviewed to assign HOA grades (0-4) using the Kellgren-Lawrence (KL) classification system. Patients with mild, moderate, and severe (KL 2-4) HOA on pre-injection radiographs were included. Primary outcomes included changes in post-injection KL grades and time-to-total hip arthroplasty (THA).

Results: There were 560 patients included, with an average age of 66.7 years, a mean BMI of 30.1, and 59.5% women. For patients with pre-injection KL grade < 4 (i.e., mild and moderate HOA or KL grades 2 and 3), there was HOA progression of one level in 185 (45.7%) patients. In the 147 (26.3%) patients with a pre-injection KL grade < 3 (i.e., mild HOA or KL grade 2), 32 (21.8%) increased by two levels. From the total cohort, 491 (87.6%) patients ultimately underwent THA. The average time-to-THA was 206 ± 95.6 days. There were no significant differences between pre-injection and post-injection patient-reported outcomes (PROs).

Conclusion: Radiographic comparisons before and after IACSI revealed concerning HOA progression in over half the patients without severe HOA. Combined with a minimal change in PROs and most patients electing to undergo THA within the following months, the safety and utility of IACSI in this population must be reconsidered.

Level of evidence: III.