On the MRI Signature of Healed Juvenile Osteochondritis Dissecans (JOCD) in the Knee – The ‘Scar Sign’

Healing of Juvenile Osteochondritis Dissecans requires progressive lesion ossification and osseous bridging with the parent bone. The ‘Scar Sign’ is an MR imaging finding that documents a healed knee JOCD lesion and is characterized by a distinct hypointense line at the prior lesion – parent bone interface, best identified on PD- or T1-weighted images w/o FS on routine clinical MRI. Knowledge of stages, timeline of healing and expected MR imaging findings of JOCD is important for the reporting Radiologist. It will facilitate prognostication and can serve as a reliable outcome measure for future research on evidence based Juvenile Osteochondritis Dissecans management.