Avascular necrosis Flashcards
What are the causes of avascular necrosis?
Trauma related:
- Dislocation or fracture
Non-trauma related:
- Steroids
- Alcohol
- BM-problems
- High dose radiotherapy
- SCD
- Hyperfibrinolysis
- Thrombophilia
- Protein S/C deficiency
- Perthe’s
What classification is used for avascular necrosis?
Ficat
Summarise the Ficat classification.
I - no XR changes
II - early XR changes
III - bone destruction
IV - collapse
What are the clinical features of avascular necrosis?
Initially asymptomatic
Pain in affected joint
What investigations would you do to diagnose avascular necrosis?
MRI is the investigation of choice - more sensitive than radionucleotide bone scanning
Plain XR - normal initially but may see osteopenia and microfractures; later show collapse of the articular surface
What is the management of avascular necrosis?
Conservative
Arthroplasty - if older; or if joint collapse has occurred
Realignment osteotomy or arthrodesis - in younger patients
What are the more common sites for avascular necrosis?
Neck of femur - after fracture of NOF or dislocation
Proximal pole of scaphoid bone - after fracture through waist of scaphoid
Body of talus - after a fracture through its neck
How does avascular bone appear on XR?
Whiter (more dense)
What types of osteonecrosis occur only in children?
Perthe’s disease - osteonecrosis of the femoral head
SUFE - slipped capital femoral epiphysis
What are the complications of avascular necrosis?
Collapse
Arthritis - due to loss of bone shape
