Avascular necrosis of the femoral head in a patient with Fabry's disease: identification of ceramide trihexoside in the bone by delayed-extraction matrix-assisted laser desorption ionization-time-of-flight mass spectrometry.

Fabry's disease is a lipid storage disease caused by an X-linked hereditary deficiency of alpha-galactosidase. The enzymatic defect causes progressive deposition of ceramide trihexoside (CTH) in various tissues, leading to renal failure, premature myocardial infarction, and stroke, with a high rate of mortality in younger patients. Among the complications associated with Fabry's disease, a few cases involving avascular necrosis (AVN) of the femoral head have been reported. However, direct evidence of deposition of CTH in bone marrow in the femoral head has not been demonstrated. This report describes a 58-year-old man who underwent total hip arthroplasty for femoral head AVN associated with Fabry's disease. The accumulation of CTH was examined by chemical analysis of the sphingolipid extracted from the femoral head, using delayed-extraction matrix-assisted laser desorption ionization-time-of-flight mass spectrometry. This is the first report confirming the presence of CTH in the sphingolipid fraction from normal and necrotic bone of a patient with Fabry's disease.