School ager who tripped and fell, heard a pop, and then developed left hip pain

Radiograph and CT of slipped capital femoral epiphysis
AP radiograph of the pelvis (upper left) shows the left femoral metaphysis to be displaced laterally from its epiphysis. This is better demonstrated on the coronal CT without contrast of the pelvis (upper right) and 3D CT of the pelvis (below)

The diagnosis was slipped capital femoral epiphysis (Salter-Harris Type I fracture) of the left femur.