OSTEONECROSIS AND OSTEOCHONDROSIS Flashcards
Unit 3 study
Osteonecrosis: Defined as
death of the osseous cellular components and marrow of bone d/t inadequate blood supply
M/C hematologic condition of bone
Osteonecrosis
What is the AKA for Osteonecrosis
Ischemic necrosis,
aseptic necrosis,
avascular necrosis,
bone infarction
What is the first and second MC avascular necrosis site involved in osteonecrosis?
MC Femoral head
2nd MC Humeral head
Osteonecrosis bone infarct occurs where
Metaphseal or
Diaphyseal
What term is used when osteonecrosis is in the bone end or juxta-articular involvement?
What is the MC location?
Avascular necrosis
Femoral head, 2nd mc is humeral head
The term Bone infarct is used when osteonecrosis is in what part of the bone?
Metaphyseal or Diaphyseal
What is the latent period for symptoms to develop in osteonecrosis?
a few weeks to 1 year
Name the 4 mechanisms of infarction
Intraluminal obstruction
Arterial wall disease
Vascular compression
Physical disruption of vessel
A temporary loss of blood flow can lead to
bone ischemia
A prolonged decrease in blood flow can lead to
Bone infarction
What are the more common causes (predispose) of osteonecrosis?
Vascular, Drugs, Congenital, Trauma
Infection, Inflammatory, Autoimmune, Endocrine
Spontaneous
Osteonecrosis vascular cause is associated with
Hemoglobinopathies
What OSTEONECROSIS: cause is associated with Infections?
Septic emboli
What OSTEONECROSIS: cause is associated with Drugs/Toxins?
Alchololism and steroids
What OSTEONECROSIS: cause is associated with inflammation?
Pancreatitis
What OSTEONECROSIS: cause is associated with congenital disorders/diseases?
Gaucher’s disease
What OSTEONECROSIS: cause is associated with autoimmune disease?
SLE and RA
What OSTEONECROSIS: cause is associated with Trauma?
Radiation
Fractures*
Dysbarism
What OSTEONECROSIS: cause is associated with the endocrine system?
Cushing’s disease
What OSTEONECROSIS: cause is knowns as an additional non-specific cause?
Spontaneous*
Metaphyseal-Diaphyseal infarctions Central area of necrosis is surrounded by what?
ischemic and healing tissue
Most common location of metaphyseal/diaphyseal infarction from greatest to least is
Distal femure, proximal tibia and proximal humerus
What are some clinical indications of a serious underlying problem?
Diabetes, Alcoholism, Chronic renal disease
Osteonecrotic meta/di-aphyseal infarcts may be
cortical or medullary
Osteonecrosis infarcts are usually what?
Asymptomatic
Radiographically, osteonecrotic infarct are first seen as a area of what?
What type of calcifications are seen on the rim?
Internally, the area may look like
rarefaction
Undulating or sepiginous
sclerosis/calcifications
What radiographic feature can be observed in the bone?
Split cortex, periosteal response
What does the bone look like on a radiographic film?
small tubular bones
What is the MC cause of osteonecrosis is associated with trauma?
Fractures
What MC drugs/toxins cause of osteonecrosis?
Alcoholism and steroids
What is the preferred source of imaging used to detect osteonecrosis infarct?
MRI
2nd best is Bone scintigraphy
With metaphyseal diaphyseal infarct its radiographic feature is usually?
An osteopenia is an area of osteonecrosis infarct radiographic feature?
Medullary and central
area of rarefaction
Cortical infarctions are usually seen in who?
In what location?
Young patients with SC
small tubular bones
What are the two most common skeletal locations for osteonecrosis?
Femoral head, Humeral head
What are two DDX for metaphyseal diaphyseal infarction? Lesions in this area are usually what?
enchondroma and low-grade chondrosarcoma
Elongated
What radiographic finding is pathognomonic of avascular necrosis?
Crescent sign
Avascular necrosis usually begins in what region of the femoral head?
Anterior superior
What imaging procedure is most sensitive for the early detection of osteonecrosis?
MRI
What are the four mechanisms of infarction?
intraluminal obstruction, Arterial wall disease, Vascular compression, Physical disruption of vessel
