Presentation
Progressive left knee pain without previous history of trauma.
Patient Data
There is a centrally located area of hypointense signal on T1W which showed marrow edema signal intensity radiating outward from the physis into the distal femoral metaphysis on fluid sensitive sequences. Finding consistent with focal periphyseal edema zone
Minimal joint effusion is seen.
Case Discussion
Focal periphyseal edema (FOPE) zones can be seen in adolescents and likely relates to the early stages of physiologic physeal closure. It may be associated with pain particularly when no other MRI abnormalities are present.
When the characteristic appearance of a FOPE zone is observed on MRI, we suggest that it not be mistaken for an abnormality, requires no invasive diagnostic procedure, and does not need imaging follow-up.
Close differential diagnosis includes Salter-Harris fracture, stress fracture, contusional bone marrow edema and chronic recurrent multifocal osteomyelitis.