(Case courtesy: Sapthagiri Digital Imaging Center, Bangalore)

Avascular necrosis of femoral head

Arlet Ficat staging

Stage 0 – Normal

Stage 1 – Only marrow edema

Stage 2- Geographic defect (As seen in this case)

Stage 3- Crescent sign and eventual cortical collapse (Subchondral crescent in case, although no collapse).

Stage4- Secondary degenerative changes.

This case may be labeled Stage 2, progressing to stage 3.

Mitchell staging

CLASS A: Fat (T1 bright T2 intermediate)

CLASS B: Blood (T1 bright T2 bright)

CLASS C: Fluid (T1 hypo T2 hyper)

CLASS D: Fibrosis (T1 hypo T2 hypo)

This case appears class A.

Which bone is most common location of AVN?

Femoral head.

This Indian patient was a chronic alcoholic, travelled recently from middle east, with no history of recent acute trauma. What could be a likely predisposition of AVN in this patient?

Alcoholism is commonly associated with AVN.

Can you specifically guess, which arterial supply may be have been interrupted?

Most common artery involved is ‘lateral epiphyseal artery’, probably in this case too. Anterolateral femoral head is most commonly involved by AVN.

Do you see a ‘double line sign’ in this case?

Yes, at most anterior aspect of involved region.