The patient, a 10-year-old boy, had a history of osteogenesis imperfecta with multiple prior fractures. He had undergone a 2-year series of treatments with intravenous pamidronate every 3-4 months, for a total of 7 treatments. Radiography of the knees revealed 7 metaphyseal bands of increased density paralleling the contours of the physis in the distal femur, proximal tibia, and proximal fibula, corresponding to the number of treatment cycles he had undergone. Pamidronate, a bisphosphonate, is an osteoclast inhibitor that has been used in adults to increase bone mineral density. Radiographic changes in children receiving cyclic bisphosphonate therapy have been described, and include increased bone mineral density and the presence of multiple thin, sclerotic metaphyseal bands corresponding to the number of treatments. The term zebra lines has been proposed to describe this characteristic banding pattern.
From Arthritis and Rheumatism
From Arthritis and Rheumatism
