Avascular Necrosis

Question 1

What is avascular necrosis?

Answer 1

Ischaemic necrosis of bone predominantly in adults

Question 2

Where is prone to AVN?

Answer 2

Femoral head 
Femoral condyles 
Head of humerus 
Capitellum 
Proximal pole of scaphoid 
Proximal part of tallus

Question 3

What is AVN sometimes secondary to?

Answer 3

Femoral neck
Proximal humerus
Waist of scaphoid and talar neck

Question 4

What can AVN sometimes be due to?

Answer 4

• Alcoholism
• Steroid abuse
• Primary hyperlipidaemia
• Thrombophilia
• Sickle cell disease
• Antiphospholipid deficiency in SLE
• Caisson’s disease/decompression sickness (deep sea diving)

Question 5

Consequence of AVN?

Answer 5

• Necrosis of a segment of bone
• Patchy sclerosis
• Subchondral collapse
• Irregularity of he articular surface
• Secondary osteoarthritis

Question 6

What can AVN lead to?

Answer 6

Secondary OA

Question 7

Early treatment of AVN?

Answer 7

Can be seen on MRI
-If the articular surface is not collapsed & is in an amenable site, drilling under fluoroscopy to decompress the bone, prevent further necrosis and help healing

Question 8

How to treat AVN if the articular surface is collapsed?

Answer 8

Joint replacement