Snapshot A 27-year-old female presents with knee pain. Her pain worsens when she is running downhill or climbing up the stairs. She describes the pain as "achy" and being behind the knee. When sitting for long periods of time, she reports her knees feeling stiff. She denies any recent history of trauma and has never had surgery. She has tried multiple over-the-counter analgesics but were not effective. She is a high school teacher and an avid runner who is preparing for a marathon. A full knee examination is performed. Introduction Overuse of patellofemoral area involving the knee and the retinaculum usually presents as anterior knee pain aggravated by weight bearing activity (e.g., running) Etiology overuse (most common) malalignment and trauma are also risk factors may be secondary to patellofemoral joint overload Epidemiology more common in women commonly seen in runners or cyclists Presentation Physical symptoms anterior knee pain worsened with ascending or descending stairs, running, and squatting Evaluation Clinical diagnosis no pathognomonic findings patellofemoral compression test Differential Chondromalacia Patellofemoral osteoarthritis Iliotibial band syndrome Prepatellar bursitis Treatment Physiotherapy (first-line) decreasing exercise intensity activity modification strengthening and stretching movements Pain management foot elevation, ice, and compression little evidence supporting effectiveness of NSAIDs and acetaminophen may be used if pain not relieved by ice or if pain with daily activities Prognosis, Prevention, and Complications Prognosis favorable prognosis Complications may have to limit sports activities