Flexion Therapeutics, Inc. announced that the American Academy of Orthopaedic Surgeons (AAOS) included ZILRETTA (triamcinolone acetonide extended-release injectable suspension) in its updated evidence-based clinical practice guidelines for the management of osteoarthritis (OA) of the knee. The AAOS guidelines reflect a moderate recommendation for the use of intra-articular (IA) corticosteroids for patients with symptomatic OA of the knee. The recommendation follows a review of data from 25 studies assessing IA corticosteroids. Included in its rationale is a differential analysis of extended-release intra-articular steroid, of which ZILRETTA is the only available product, versus immediate-release IA corticosteroids, where AAOS analyses demonstrated that it can, “be used over immediate-release corticosteroids to improve patient outcomes.” The AAOS guidelines serve as an educational tool to help guide clinical treatment decisions to improve the quality and effectiveness of care and were last revised in 2013. Indication and Select Important Safety Information for ZILRETTA -Indication: ZILRETTA is indicated as an intra-articular injection for the management of osteoarthritis pain of the knee. Limitation of Use: The efficacy and safety of repeat administration of ZILRETTA have not been demonstrated. Contraindication: ZILRETTA is contraindicated in patients who are hypersensitive to triamcinolone acetonide, corticosteroids or any components of the product. Warnings and Precautions: Intra-articular Use Only: ZILRETTA has not been evaluated and should not be administered by epidural, intrathecal, intravenous, intraocular, intramuscular, intradermal, or subcutaneous routes. ZILRETTA should not be considered safe for epidural or intrathecal administration. Serious Neurologic Adverse Reactions with Epidural and Intrathecal Administration: Serious neurologic events have been reported following epidural or intrathecal corticosteroid administration. Corticosteroids are not approved for this use. Hypersensitivity reactions: Serious reactions have been reported with triamcinolone acetonide injection. Institute appropriate care if an anaphylactic reaction occurs. Joint infection and damage: A marked increase in joint pain, joint swelling, restricted motion, fever and malaise may suggest septic arthritis. If this occurs, conduct appropriate evaluation and if confirmed, institute appropriate antimicrobial treatment. Adverse Reactions: The most commonly reported adverse reactions (incidence =1%) in clinical studies included sinusitis, cough, and contusions.