mcq

A 12 year old boy with known sickle cell with a history of recurrent painful episodes in the arms, hands and legs

complains of hip pain. The pain is exerbated by weight bearing. On examination he is noted to have a limp.

The most likely diagnosis is

a) Acute hemarthrosis

b) Osteonecrosis

c) Baker's cyst

d) pigmented villonodular synovitis

e) rheumatoid arthritis

Correct answer: B

EXPLANATION

Osteonecrosis, also called avascular or ischemic necrosis, results from bone death secondary to an impaired

blood supply. The femoral head is commonly involved, leading to hip-joint arthritis, but any other joint can be

affected. Symptoms include pain, especially when bearing weight, limping and the eventual restricted movement

of the involved joint. Osteonecrosis should be considered in young people with risk factors such as corticosteroid

use, hemoglobinopathies or sickle cell disease, as well as in alcoholic and elderly diabetic patients