Osteonecrosis Flashcards
With ?, the bone marrow cells die within ? hours, followed by the
bone cells (?, ? and ?) between 12-? hours.
Osteonecrosis in the ? of a ? bone is typically described as bone infarction, and only involves the ? bone and bone marrow in the
? (? has blood supply by the periosteum).
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Osteonecrosis in the ? of ? bones is called avascular necrosis, and this may involve the ? bone as the ? are covered by cartilage and thus doesn’t have ? supply .
Common causes of osteonecrosis are;
0 Interrupted arterial supply (e.g. ?).
0 Interrupted venous drainage and ? arterial stoppage (e.g. ?, or bone ? ? compressing vessels).
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Risk Factors;
- Fracture: e.g. ? NOF fracture, ? fracture.
- Idiopathic: e.g. ? disease, ? of the femoral head.
- Bone marrow infiltration: ?.
- ? abuse.
- ?’s/exogenous corticosteroids/?therapy.
- Infection: ? arthritis.
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Certain bones are more susceptible;
o The head of the ?: following fractured ? or ? dislocation.
o The ? scaphoid: following a ? wrist fracture.
o The ?: following dislocation.
o The body of the ?: after ? ? fracture.
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Osteonecrosis is often well ? at presentation.
Symptoms are ?, ? and swelling in a ? joint, or over the ? depending on the location.
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XR will show a ? segment of increased bone ? (due to ? bone formation), however this will only be present after six ?.
MRI/? scans can show ? changes.
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Treatment is to eliminate the ?, prevent complications (e.g. # prevented by ? relief and ?), with potential ? intervention
cause
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