Figure 1 is a radiograph of the left lower limb of a two-year-old child. It demonstartes multiple linear areas of increased bone density at the metaphysis of the proximal and distal femur and circumferential linear thickening of the cortex around the iliac with background osteopenia and a non united fracture of the shaft. He was diagnosed as having Osteogenesis Imperfecta (OI) type 3 in early infancy and was given cyclical Pamidronate therapy for the same. It is likely that the areas of increased bone density correspond to the timings of the Pamidronate infusions.

Fig.1. X-ray showing multiple linear areas of increased bone density in a child on cyclical pamidronate therapy.

There has been an increase in the usage of Biphosphonates like Pamidronate to enhance bone density in various disorders associated with osteopenia including osteopathies such as OI, juvenile osteoporosis, Gaucher’s disease, hyperphosphatasia, juvenile chronic arthritis and glucocorticoid-induced osteoporosis. They have also been tried for treatment of calcinosis associated with myositis, fibro-dysplasia ossificans, dermatomyositis and scleroderma. Increased bone density, cortical width, reduced fracture rates and improved bone pain are known benefits from Pamidronate therapy in OI(1). A reduced rate of bone turnover due to decreased osteoclast activity is thought to result in a better balance between bone formation and resorption leading to an increase in bone mass. The lines of increased bone density are likely to be the result of an increase in both the number of trabeculae and the amount of residual calcified cartilage within the secondary spongiosa(2). This radiographic appearance is striking and will probably be seen more commonly with expanding indications for Biphosphonate therapy in the future, Other conditions where multiple dense transverse bands extending across the metaphysis of long bones are seen include chronic lead poisoning and in chronic disease or stress related to malnutrition in which case they are referred to as growth arrest lines.

Ramesh Srinivasan,
Department of Child Health,
Llandough Hospital,
Penlan Road, Penarth,
Cardiff, U.K., CF64 2XX,
E-mail: [email protected] 

1. Glorieux FH, Bishop NJ, Plotkin H, Chabot G, Lanoue G, Travers R. Cyclic administration of a pamidronate in children with severe osteogenesis imperfecta. N Engl J Med 1998; 339: 947-952.

2. Rauch F, Travers R, Plotkin H, Glorieux FH. The effects of intravenous pamidronate on the bone tissue of children and adolescents with osteogenesis imperfecta. J Clin Invest. 2002; 110: 1239-1241.