Avascular Necrosis (AVN) of the Femoral Head on Plain Film

AVN frequently affects the heads of the femur and humerus.

Early AVN may present with a crescentic lucency below the cortex.

Moderate AVN usually shows sclerosis of the head.

Advanced AVN shows inhomogeneous sclerosis

— and flattening of the femoral head as in this patient.

AVN is increased in patients on steroids and patients

with sickle cell anemia