Avascular Necrosis of the Hip

Question 1

define

Answer 1

this is failure of blood supply to the femoral head

Question 2

what supplies the femoral head?

Answer 2

medial femoral circumflex

Question 3

causes

Answer 3

idiopathic

secondary to alcohol, steroids, hyperlipidaemia and thrombophilia

Question 4

presentation

Answer 4

insidious onset of groin pain

exacerbated by stairs or impact

Question 5

diagnosis

Answer 5

• examination is normal unless advanced to collapse/OA
• radiographs often normal in early disease
• MRI most sensitive and will show patchy sclerosis and lytic zones have hanging rope sig (BUZZWORD)

Question 6

management for reversible AVN

Answer 6

• bisphosphonates
• core decompression (drill holes) +/- bone grafting
• curettage and bone grafting
• vascularised fibular bone graft
• rotational osteotomy

Question 7

management for irreversible ANV

Answer 7

• rotational osteotomy

- if collapsed THR