Avascular Necrosis (AVN)

Question 1

What is AVN

Answer 1

ischaemic necrosis of bone predominantly in adults.

Question 2

AVN sites ()6)

Answer 2

femoral head

the femoral condyles

the head of the humerus

the capitellum

the proximal pole of the scaphoid

the proximal part of the talus.

Question 3

What causes AVN (7)

Answer 3

idiopathic where no cause is found

AVN can also be due to =
-alcoholism
-steroid (ab)use
- primary hyperlipidaemia

-thrombophilia
-sickle cell diease
-antiphospholipid deficiency in SLE

Question 4

results of AVN (2)

Answer 4

necrosis of a segment of bone resulting in patchy sclerosis before subchondral collapse and irregularity of the articular surface occurs.

can affect osteoarthritic joints causing collapse of the articular surface and rapid deterioration.

Question 5

treatment of AVN (3)

Answer 5

depends on the stage of the disease.

early cases can be seen on MRI before any radiographic changes occur.

fusion can be considered in the wrist or foot/ankle.

Question 6

articular surface not collapsed

Answer 6

if the articular surface has not collapsed in an amenable site (usually the femoral head) drilling can be performed under fluoroscopy to “decompress” the bone, prevent further necrosis and help healing.

Question 7

articular surface has collapsed

Answer 7

if the articular surface has collapsed generally joint replacement is usually required in the hip, knee or shoulder to control symptoms.