A 9-Year-Old Boy with Pain After Twisting His Knee

The patient is a 9-year-old boy who was brought in by his parents with right knee pain. He reports that he twisted it while reenacting Star Wars battles in the backyard with friends. His parents did not witness the injury.

View the image taken (Figure 1) and consider what your diagnosis and next steps would be. Resolution of the case is described on the next page.