Abstract
BACKGROUND: Evidence has been mixed about the efficacy of intra-articular hyaluronic acid (HA) for knee osteoarthritis. This has led to conflicting clinical practice guidelines (CPGs) over the years. After the American Academy of Orthopaedic Surgeons (AAOS) issued a strong recommendation against HA in 2013, a claims-based study showed rapid decline in use. More recent endorsements from Osteoarthritis Research Society International (OARSI) in 2019 and the Veterans Affairs and Department of Defense (VA-DoD) in 2020 may have altered this trajectory. This study aimed to gauge contemporary utilization of HA knee injections. METHODS: All patients aged 18 years and older diagnosed with knee osteoarthritis were identified from the 2010Q1-2023Q1 PearlDiver database. The percentage of patients receiving intra-articular HA relative to the number of patients diagnosed for knee osteoarthritis was calculated quarterly. Linear regression analyses were segmented by 2 key CPG inflection points: 2013Q3 AAOS' recommendation against HA injections and the 2019Q4 endorsements. Analyses were also stratified by provider specialty. Statistical significance was set at p < 0.05. RESULTS: A total of 16,581,526 knee OA patients were identified, among which HA knee injections were performed for 1,886,788 (11.4%). For the post-2013 AAOS CPG period (2013Q3-2019Q3), injection rates decreased (-0.10% per quarter; p < 0.001). However, following OARSI/VA-DoD endorsement (2019Q4-2023Q1), the slope leveled to -0.003% per quarter; p = 0.921. Through the study period, utilization declined for both women and men and both younger and older patients (<50 years old and ≥ 50 years old) (p < 0.001 for all). Utilization declined among orthopaedic surgeons, nonoperative musculoskeletal specialists, and primary care physicians, while utilization increased among pain medicine physicians (p < 0.001 for all). CONCLUSIONS: Intra-articular HA injection use decreased after the 2013 CPG from AAOS but has stabilized after more positive 2019 and 2020 CPGs from OARSI/VA-DoD. Notably, practice patterns are diverging patterns across specialties, suggesting variabilities in use. LEVEL OF EVIDENCE: Level III. See Instructions for Authors for a complete description of levels of evidence.