Effect of intra-articular hyaluronic acid injection on clinical function and inflammatory factors in knee osteoarthritis

BACKGROUND: Intra-articular injection of hyaluronic acid (HA) is widely used as an alternative therapy for osteoarthritis (OA). Here we investigated whether HA injection was associated with changes in clinical function and inflammatory markers in knee OA patients.METHODS: This was an experimental study with a randomized trial. We evaluated patients with mild-to-severe primary knee OA (Kallgren-Lawrence [KL] Grade 2-4) in Makassar, Indonesia, between November 2019 and February 2021. Clinical improvement of patients was assessed by the Knee Injury and Osteoarthritis Outcome Score (KOOS) while inflammatory markers were assessed by the Erythrocyte Sedimentation Rate (ESR) as a response to intra-articular injection of HA. Evaluation was done 3 months after treatment.RESULTS: In total, 35 patients met the inclusion criteria with an average age of 60 years (the largest age group was 51-55 years). The pain, symptoms, activities of daily living (ADL), sport, and quality of life (QoL) scores according to the KOOS increased significantly after HA injection (P=0.0001, P<0.05). However, the ESR levels increased significantly after HA injection. Age, gender, Body Mass Index (BMI), degree of OA, and incidence of complications were not significantly related to the clinical improvement of patients.CONCLUSIONS: HA injection had an effect on clinical improvement as assessed by the KOOS after 3 months in patients with grade 2-4 knee OA, unlike the inflammatory markers which showed no decrease. A longer period of follow-up and a larger sample size will be needed to obtain a clearer result regarding the therapeutic efficacy.