Diagnosis: Bilateral femoral head AVN (avascular necrosis)

Modality: X-Ray

Findings: Left worse than right ill-defined findings of mixed sclerotic and lytic appearance of the bialteral femoral heads. There is mild to moderate cortical flattening with a lucency in subchondral region (“crescent sign”). No definite joint space narrowing to suggest degenerative changes.

Key Points: Avascular necrosis can result from temporary or permanent loss of vascular supply to the femoral head. AVN can occur at the ends of any long bone but is commonly involving the femoral heads. AVN can occur as a result of certain medications, ethanol use, or prior injury or surgical intervention.

Credit: Case submitted by Dr. Dr Runalaila I Soofi MD to radRounds Radiology Network