UKMLA PLAB AMC USMLE Prometric MCQ

Question Number 0757

Question:
26 year-old female with lupus erythematosus on long term treatment twisted her left hip and experienced severe pain. Radiographs were normal and she was treated with anti-inflammatory medication. No relief was evident and a clinical diagnosis of osteonecrosis was made. A plain film taken six weeks later shows collapse of the subchondral area. A likely aetiology is:

a) septic emboli
b) impaired venous drainage
c) Hgb SS disease
d) steroid use
e) alcoholism