A 25-year-old white woman was diagnosed with Crohn's disease involving the
small and large intestines. She had a complex clinical course that required
treatment with multiple pharmacological agents, including intravenous, ora
l and rectal corticosteroids. She also received parenteral nutrition with l
ipid emulsions. Finally, repeated intestinal resections and drainage of per
ianal abscesses were required. Her disease was complicated by gallstones, u
rolithiasis and hip pain. After osteonecrosis was diagnosed, joint replacem
ents were performed. Review of the pathological sections from the resected
hip, however, resulted in detection of granulomatous inflammation with mult
inucleated giant cells - the histological 'footprint' of Crohn's disease in
the gastrointestinal tract. Because prior specialized perfusion fixation p
athological studies of the intestine in Crohn's disease have shown that gra
nulomas are located in the walls of blood vessels, a possible mechanism for
the pathogenesis of osteonecrosis in Crohn's disease is chronic microvascu
lar ischemia of bone.