Approximately 5% of all primary care visits are related to knee pain. Osteoarthritis (OA), patellofemoral pain syndrome, and meniscal tears are among the most common causes of knee pain. JAMA Senior Editor Karen Lasser, MD, MPH, speaks with David Hunter, MD, PhD, from the University of Sydney, about common causes and first-line treatment of knee pain. Related Content: Evaluation and Treatment of Knee Pain Clinical Examination for Diagnosing Meniscal Tears