Location

Hip

Diagnosis

Avascular necrosis

Discussion

One image each of two separate patients with collapse and necrosis of the femoral head, both of which are secondary to repeated injection of steroids. A rapid progression of change in a joint secondary to steroid injections. Transition of a joint from one of minor alterations (such as narrowing, sclerosis) to one of significant bony fragmentation and collapse. Gouged-out areas of bony destruction may be similar to small animal bites, hence the bite sign.

Reference

Martel W, Sitterley BH: Roentgenologic Manifestation of osteonecrosis. AJR Am J Roentgenol 1969, 106;509-522.

Figures

Click thumbnail for larger image

Attachments:


pelvisavnbite2.jpg (image/jpeg)


hipavnbite.jpg (image/jpeg)