In this episode, Marc and Mo discuss the third edition of the AAOS Clinical Practice Guidelines on Osteoarthritis of the Knee, with a particular focus on the quality of evidence related to injectable therapies and the concept of “living guidelines.” OrthoJOE Mailbag: feedback, comments, and suggestions from our audience can be sent to orthojoe@jbjs.org Links: • AAOS Clinical Practice Guidelines on Osteoarthritis of the Knee (originally released in 2013, update in Aug. 2021 (https://www.aaos.org/quality/quality-programs/lower-extremity-programs/osteoarthritis-of-the-knee/) • Vannabouathong C, Bhandari M, Bedi A, Khanna V, Yung P, Shetty V, Khan M. Nonoperative Treatments for Knee Osteoarthritis: An Evaluation of Treatment Characteristics and the Intra-Articular Placebo Effect: A Systematic Review. JBJS Rev. 2018 Jul;6(7):e5. doi: 10.2106/JBJS.RVW.17.00167. https://jbjs.org/reader.php?rsuite_id=1734831&native=1&source=JBJS_Reviews/6/7/e5/fulltext&topics=kn#info • Bauer TW. Stem Cell Therapy for Knee Pain—What Exactly Are We Injecting, and Why? Editorial. J Bone Joint Surg. 2016 Sep; 98(15): 1509. doi: 10.2106/JBJS.16.00872. https://jbjs.org/reader.php?rsuite_id=1261189&native=1&source=The_Journal_of_Bone_and_Joint_Surgery/98/18/1509/fulltext&topics=bs#info Keywords: Orthopaedics, JBJS, OrthoEvidence, AAOS, CPG, OA, viscosupplementation, injectables, platelet-rich plasma, PRP, hyaluronic acid, HA, corticosteroids, changes in practice, grades of evidence, NSAIDs, acetaminophen, exercise, patient education, braces, MCID, minimum clinically important difference, 95% CI, manufacturing processes, low-molecular-weight HA, high-molecular-weight HA, living meta-analysis, living guideline, signal-to-noise ratio