Effect of Intra-articular Ketorolac Versus Corticosteroid Injection for Knee Osteoarthritis: A Retrospective Comparative Study

BACKGROUND: Intra-articular corticosteroid injections have been widely used and are considered a mainstay in the nonoperative treatment of symptomatic knee osteoarthritis (OA). However, their increased use can have negative implications, including chondral toxicity and a high risk of infections. As a result, nonsteroidal anti-inflammatory drugs have been considered as an alternative. PURPOSE: To determine the pain relief and safety of ketorolac versus a corticosteroid to supplement an intra-articular sodium hyaluronate injection for the treatment of symptomatic knee OA. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A total of 84 patients with unilateral symptomatic knee OA receiving 5 weekly injections were enrolled in this retrospective study. Group A (n = 42) received 3 weekly intra-articular corticosteroid injections (0.5% lidocaine, 25 mg of triamcinolone acetonide, and 25 mg of sodium hyaluronate, followed by 2 weekly injections of 0.5% lidocaine and 25 mg of sodium hyaluronate), while group B (n = 42) received 5 weekly ketorolac injections (0.5% lidocaine, 10 mg of ketorolac, and 25 mg of sodium hyaluronate). The following parameters were used to evaluate pain relief and safety: visual analog scale (VAS) for pain, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and side effects before the injection and at 1, 2, and 5 weeks after treatment commencement as well as 3 months after the last injection. RESULTS: Patients from both groups had a significant improvement in VAS and WOMAC scores from the first injection to final follow-up at 3 months. In the first week, the VAS score was lower in group A (P = .041), but no significant between-group differences were found for either the VAS or the WOMAC score at the other time points. Of the 42 patients in group A, 34 (81.0%) and 25 (59.5%) achieved successful outcomes at 5 weeks after treatment commencement and 3 months after the last injection, respectively. In group B, 32 (76.2%) and 24 (57.1%) patients achieved successful outcomes at 5 weeks after treatment commencement and 3 months after the last injection, respectively. At final follow-up, no significant difference was found in the successful treatment rate between the groups (P = .825). CONCLUSION: The current study demonstrated that intra-articular ketorolac and corticosteroid injections produce the same pain relief and functional improvement.