الفهرس 
AnatomyOnly 14 pages are availabe for public view
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Abstract
Osteonecrosis of the hip is a disease that generally affects patients
in the third to fifth decades of life and therefore has significant impact
on the work and leisure activities of these patients.
The femoral head is the most vulnerable site for development of
osteonecrosis. The site of necrosis is usually immediately below the
weightbearing articular surface of the bone, the anterolateral aspect of
the femoral head. This is the site of greatest mechanical stress.
The head of the femur is entirely intracapsular, and therefore the
blood supply of the head is of surgical importance. Around the neck,
at the attachment of the fibrous capsule of the hip joint, is a vascular
ring supplied by the branches of the medial and lateral circumflex
arteries.
Osteonecrosis seems to develop as a result of a multifactorial
process rather than one precipitating event. Certain patients probably
are predisposed to having osteonecrosis develop because of an
inherent hypercoagulable state. Patients who are taking corticosteroids
clearly are at risk for having osteonecrosis develop.
Especial attension should be directed to patients who have any of
the risk factors and negative radiograph findings. This is especially
true with unilateral involvement because of the high risk of
developing osteonecrosis in the contralateral hip. These patients
should be evaluated aggressively.