There’s No Patellin’ What Happened

ANSWER

The radiograph demonstrates an abnormal-appearing patella; there is a longitudinal lucency along the lateral portion. There is some mild soft-tissue swelling but no evidence of a definite joint effusion. The lucency could represent a fracture, especially in the setting of trauma. The other possibility is that the patient has a bipartite patella. This is a rare congenital condition in which the patella does not completely fuse; it remains two separate bones. CT of the knee for further evaluation, as well as orthopedic consultation, were ordered.