Effects of intraarticular IL1-Ra for acute anterior cruciate ligament knee injury: a randomized controlled pilot trial (NCT00332254)

Summary Objective To evaluate the clinical effectiveness of intraarticular IL-1 receptor antagonist (IL-1Ra) for anterior cruciate ligament (ACL) tear. Methods Eleven patients with acute ACL tear confirmed by magnetic resonance imaging (MRI) were randomized to receive a single intraarticular injection of IL-1Ra (anakinra 150 mg, n = 6) or equal volume of saline placebo (1 ml, n = 5). The double-blinded treatment was administered a mean 2 weeks after injury. Synovial fluid (SF) ( n = 9 patients) and sera (all patients) were available at baseline (prior to injection) and immediately prior to surgery (mean 35 days later) and analyzed for SF IL-1α, IL-1β, IL-1Ra and serum hyaluronan (HA), an indicator of synovial inflammation. The primary outcome, standardized Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire, was obtained at 0 (baseline), 4, and 14 days after injection. Results Compared with placebo, the IL-1Ra group had substantially greater improvement in key outcomes over 14 days (KOOS pain P = 0.001; activities of daily living P = 0.0015; KOOS sports function P = 0.0026; KOOS quality of life (QOL) P = 0.0048; and total KOOS P