Dorsal Defect of the Patella in a Teenage Male Football Player

Dorsal defect of the patella (DDP) is a well-documented yet infrequently observed osteolytic lesion on the superolateral aspect of the patella, primarily occurring in the second and third decades of life. The plain radiographic appearance of DDP is typically a round radiolucent lesion with a peripheral sclerotic margin. On a magnetic resonance imaging (MRI) fluid-sensitive series, DDP is demonstrated as a hyperintense focal contour abnormality. Often asymptomatic, DDP is frequently discovered as an incidental finding in up to 75% of cases. This often occurs when investigating etiologies of symptomatic differential diagnoses, such as osteochondritis dissecans, meniscal tears, ligamentous injury, chondromalacia, and patellar instability.