Acquired osteosclerosis associated with intravenous drug use and hepatitis C infection.

Hepatitis C has recently been recognized as a secondary cause of osteosclerosis; a further example, the first outside of North America, is described. A 37-year-old man with a history of intravenous drug use and known to be hepatitis C antibody positive presented with bone pain. Radiographs and magnetic resonance imaging demonstrated an increase in cortical and trabecular bone that on biopsy was of a normal lamellar pattern but markedly sclerotic. Biochemical markers of bone formation (serum osteocalcin) and resorption (urinary hydroxyproline excretion rate) were both markedly elevated. Pain lessened following administration of pamidronate. Biochemical markers of bone turnover fell towards their reference ranges 12 months after initiating pamidronate therapy but without significant change in bone mineral density. Osteosclerosis is a rare complication of hepatitis C infection, the symptoms of which are controllable with diphosphonate therapy.