A Toddler with a Sudden Limp

Case
The patient is a 3-year-old female who is brought to your urgent care center by her parents, who report that she has been limping and crying intermittently seemingly without reason for the past several hours. Her father says she cries acutely when picked up, but that she calms down quickly with comforting.

View the images taken (Figure 1 and Figure 2) and consider what the diagnosis and next steps would be. Resolution of the case is described on the next page.