Radiology Resident Case of the Week: August 1, 1996

Osteonecrosis - Bilateral femoral heads

Marta Bogdanowicz, M.D.
Peer Review Status: Internally Peer Reviewed

Clinical Sx:
Left hip pain
This 17-year-old female presents with a history of acute lymphocytic leukemia, with records of the illness going back to 1990.

Etiology/Pathophysiology:
In this case the process is most likely related to steroid use. The causes associated with the process include:

toxins-

1. steroids
2. anti-inflammatory drugs
3. alcohol
4. immunosuppressives

traumatic-

1. idiopathic
2. fractures
3. radiotherapy
4. heat
5. fat embolism

inflammatory-

1. rheumatoid arthritis
2. systemic lupus erythematosus
3. scleroderma
4. infection
5. pancreatitis

metabolic and endocrine-

1. pregnancy
2. diabetes
3. cushing's syndrome
4. hyperlipidaemias
5. gout

Hematopoetic disorder

1. hemoglobinopathies
2. polycythemia rubra vera
3. Gaucher's disease
4. hemophilia

thrombotic and embolic-

1. dysbaric osteonecrosis
2. arteritis according to Dahnert, involvement of one hip increases the risk to the contralateral hip to up to 70%

Imaging:

plain film:
grade 0= normal/ mild degenerative change
grade 1= barely detectable trabecular mattling
grade 2= faocal sclerosis/ trabecular rarefaction in femoral head
grade 3= mild alteration in femoral head contour + normal joint space
grade 4 = profound flattening of femoral head
grade 5= narrowing of joint space and acetabular involvement

Nuc Med:
early- cold, photopenic defect (interrupted blood flow) late- increased uptake (capillary infiltrate and new bone synthesis)

MRI:
1) central area of high signal intensity on T1WI
2) large irregular areas of decreased signal intensity extending into femoral neck
3) low intensity band/ring on T1WI
4) cleft of low signal intensity on T1WI and high signal intensity on T2WI.

Key References:
1. DAhnert, Radiology Review Manual Chapman, Radiological differential diagnosis

Keywords:
AVN, Osteonecrosis

Title Page

See related Provider Topics Bones, Joints and Muscles or Osteonecrosis.

See related Patient Topics or Bones, Joints and Muscles.

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