JBJS JOPA Image Quiz: 74-Year-Old Woman with Knee Pain

This month’s Image Quiz from the JBJS Journal of Orthopaedics for Physician Assistants (JOPA) presents the case of a 74-year-old woman with a 2-month history of left knee pain. She was given an intra-articular knee injection for presumed osteoarthritis, which failed to provide any relief. At a follow-up visit, clinicians obtained the MRI shown here.

Pick among five possible diagnoses: secondary osteonecrosis, transient osteoporosis, spontaneous osteonecrosis, osteochondritis dissecans, or bone marrow edema lesion.