Young Man with Swollen Knee

Abstract

A 33-year-old otherwise healthy man presented to the emergency department with left knee pain. Before arrival, the patient had been attempting to start his motorbike, when his pants leg was caught, causing hyperextension of the knee. Physical examination revealed a knee effusion, normal neurovascular function, and inability to range the knee as a result of pain. Bedside ultrasonography was performed (Figure 1).