Broadening the Differential for Unilateral Knee Pain: A Diagnostic Case Study

In this diagnostic case study, a 26-year-old woman presented to a community internal medicine practice with a complaint of chronic, atraumatic, unilateral knee pain. Distinguishing red flag symptoms within the patient history can guide the nurse practitioner in formulating a broad differential diagnosis with age considerations to pick up on uncommon diagnoses manifesting in common primary care symptoms. Subsequently, this influences the decision-making process for radiographic imaging necessity in a common chief complaint. Abnormal radiographic imaging may require immediate referral to multidisciplinary specialists for further workup and management. •Consider broad differential diagnoses with red flag symptoms in knee pain.•Chronicity and nighttime awakenings are red flag symptoms prompting radiography.•Chronic knee pain management and follow-up may involve multiple specialties.