Man With Knee Pain

An otherwise healthy 38-year-old male patient, who works as a carpenter, presented to the emergency department complaining of left knee pain. He reported kneeling on his left knee for an extended period during work one day before this episode. The pain was exacerbated when bending his knee and partially relieved when at rest. Physical examination revealed redness, swelling, and tenderness in the infrapatella region (Figure 1). Plain radiography showed no apparent bony abnormalities. Point-of-care ultrasonography was performed (Figure 2).