Background: Knee osteoarthritis (OA) is a common form of arthritis in elders which can lead to reduced daily activity and quality of life. It is important to administer a proper treatment with high efficacy and low side effects. In this study, we evaluated the efficacy of co-treatment with oral duloxetine and intraarticular (IA) injection of hyaluronic acid (HA) and corticosteroid (CS) in patients with knee OA.
Objectives: This study aimed to test the hypothesis that an IA injection of CS+HA combined with duloxetine could achieve pain management superior to that of an IA injection of CS+HA alone in patients experiencing knee OA related pain.
Study design: This study adopted a prospective, randomized, open-label blind endpoint study design.
Setting: The investigation was performed at Beijing Tiantan Hospital Affiliated with the Capital Medical University from October 2019 to December 2021. The study plan was approved by the Ethics Committee of Beijing Tiantan Hospital (KY 2019-086-02).
Methods: A total of 150 patients were randomly allocated to receive either duloxetine combined with an IA injection (n = 75) or a single IA injection alone (n = 75). All patients were followed for 24 weeks. The primary outcome was the change in the weekly 24 hours average mean pain scores, and the secondary outcomes included the proportion of patients with >= 30% or >= 50% pain reduction, Brief Pain Inventory (BPI) items, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores, Patient Global Impression Improvement (PGI-I) ratings, hospital anxiety and depression scale (HADS) scores and adverse events (AEs)..
Results: Patients in the experimental group had significantly greater improvement in the change of weekly mean of the 24 hours average pain scores, BPI pain severity ratings (P < 0.001) and WOMAC scores (P < 0.001) at the study endpoint. A significantly greater percentage of patients in the experimental group rated PGI-I of <= 2 (P = 0.021) and >= 50% pain reduction (P = 0.029) at 24 weeks. There was no difference in the proportion of patients with <= 30% pain reduction, the HADS scores or frequency of AEs between the 2 groups.
Limitations: The effectiveness and safety were examined only up to 24 weeks after treatment, and we did not perform a long-term follow-up as most previous studies have. Optimum dosage of duloxetine, as well as different molecular-weight HA, should be investigated in future studies.
Conclusion: Patients receiving co-treatment with oral duloxetine and IA (HA+CS) injections experienced considerable improvement in pain and knee function compared to those who received an IA injection alone.
Keywords: co-treatment; corticosteroid; duloxetine; hyaluronic acid; intraarticular injection; knee osteoarthritis; Pain management.