4. Bones Affected
ā¢ Femoral head ā most common by far
ā¢ Shoulder ā humeral head
ā¢ Odontoid (Neck)
ā¢ Scaphoid (Wrist)
ā¢ Lunate (Wrist)
ā¢ Talus (Ankle)
12. Stage 0
ā¢ No clinical symptoms
ā¢ No radiographic abnormalities
ā¢ Microscopic diagnosis
13. Stage I
ā¢ May or may not have symptoms
ā¢ Radiographs and CT are normal
ā¢ MRI is abnormal as is bone scan
ā¢ Microscopic exam confirms diagnosis
14. Stage II
ā¢ Patient is symptomatic
ā¢ X-rays show osteopenia, sclerosis, cysts
ā¢ No subchondral lucency or collapse
ā¢ MRI confirms diagnosis
15. Stage III
ā¢ X-rays show subchondral lucency and collapse
Crescent sign
ā¢ Shape of femoral head is preserved
ā¢ Subclassified by extent of crescent
IIIa 15% of head
IIIb 15-30% of ahead
IIIc greater than 30%
16. Stage IV
ā¢ Flattening or collapse of head on x-ray
ā¢ Loss of joint space
ā¢ Subclassified by extent of collapse like Stage III
IVa
IVb
IVc
25. Free Vascularized Fibular Graft
ā¢ Pioneered in 1979 by Dr. Urbaniak at Duke
ā¢ Over 2500 performed
ā¢ Multidisciplinary approach
ā¢ Only center with real consistent results
39. Summary
ā¢ AVN is the disruption of the blood supply to
bone
ā¢ There are multiple causes
ā¢ Diagnosis may be delayed
ā¢ Treatment is dependent on stage and other
factors
40. Sources
Staging of Avascular Necrosis. Orthopaedia Main. In:
Orthopaedia-Collaborative Orthopaedic Knowledgebase
JBJS Br. Core Decompression of the Distal Femur. Vol. 71-B.
August, 1989
JBJS. Treatment of Osteonecrosis with Free Vascularized Fibular
Graft. Vol 77. 1995