avascular necrosis of the hip

Question 1

what is avascular necrosis (AVN)?

Answer 1

death of bone tissue secondary to loss of blood supply, leading to bone destruction and loss of joint function

Question 2

where does AVN commonly affect?

Answer 2

epiphysis of long bones e.g. femur

Question 3

what are the causes of AVN?

Answer 3

• long-term steroid used
• chemotherapy
• alcohol excess
• trauma

Question 4

what are the features of AVN?

Answer 4

• initially asx

- pain in affected joint

Question 5

how do you ix for AVN?

Answer 5

MRI is the ix of choice

plain XR findings may be normal initially

• osteopenia and microfractures may be seen early on
• collapse of articular surface may result in crescent sign

Question 6

what is the mx for AVN?

Answer 6

joint replacement