The KINDLE trial: ketorolac vs. triamcinolone injections for lateral epicondylitis- a non-inferiority randomized controlled multicentric trial

Lateral epicondylitis (LE) is commonly treated with triamcinolone injections, but ketorolac, a nonsteroidal anti-inflammatory drug (NSAID), may offer a safer alternative. This non-inferiority trial evaluated whether ketorolac is non-inferior to triamcinolone in LE patients for pain relief measured by Visual Analog Scale (VAS) at 24 weeks (primary outcome, non-inferiority margin: 1 cm). In this randomized, controlled trial, 200 patients with LE were randomized to receive triamcinolone (2 mL, 40 mg/mL) or ketorolac (2 mL, 30 mg/mL) injections using peppering or single-injection technique, with or without ultrasound guidance. Primary outcome was VAS pain at rest change at 24 weeks. Secondary outcomes included Patient-Rated Tennis Elbow Evaluation (PRTEE), Disabilities of the Arm, Shoulder, and Hand (DASH) scores, strength parameters, and adverse events at 4, 12, 24, and 52 weeks. Non-inferiority was assessed using one-sided 95% confidence intervals (CIs), with linear mixed-effects models and subgroup analyses performed. At 24 weeks, ketorolac was noninferior to triamcinolone for VAS pain at rest [mean change: -1.08 &#xb1; 2.04 vs. -1.01 &#xb1; 2.31; mean difference: 0.072; 95% CI: -0.538 to 0.681; (upper bound <1 cm)]. Both treatments showed comparable functional outcomes across secondary measures. Subgroup analysis suggested ketorolac approached noninferiority in patients with symptom duration <12 months, whereas patients having chronic symptoms (&#x2265;12 months) showed superior response to triamcinolone. Adverse events (mild pain/swelling) were comparable in both groups (10.6% in ketorolac and 14.4% in triamcinolone group), though transient post-injection pain was more frequent with ketorolac. Ketorolac injection provides pain relief and functional outcomes comparable to triamcinolone for LE, offering a safe and effective steroid-sparing alternative, particularly for patients with shorter symptom duration or contraindications to corticosteroids.