Objective: To determine the efficacy and safety of pamidronate combined with intramedullary rodding in improving bone mineralisation and reducing fracture incidence in children with osteogenesis imperfecta (O.I.).

Methods: A prospective pilot, open study was performed in which intravenous pamidronate was administered at 1.5 mg/kg bi-monthly to 12 children with O.I., over 18 – 28 months. The children were serially monitored for symptoms, anthropometric measurements, fracture incidence, biochemical assessments of calcium metabolism, bone mineral density (BMD), serum alkaline phosphatase (ALP), urinary N-telopeptides, and spine X-rays. Intra-medullary rodding of fractures were performed with when there was definite angulation of bones.

Results: The number of fractures decreased from 4 to 0.85 fractures/year during pamidronate therapy (p< 0.05). After 18 months of treatment, there was significant improvement in Areal BMD z scores of the lumbar spine from −2.38 to −1.76 (p < 0.05) and in the Volumetric BMD, which increased from 0.06 to 0.09 g/cm3 (p < 0.05). At 18 months, urine N-telopeptide levels (bone resorption marker), decreased from 439.7 to 222.3 BCE/Cr (p < 0.05), and serum ALP (bone formation marker) from 225.0 to 143.5 U/L (p < 0.05), reflecting reduced bone turnover. This may represent a net reduction in bone resorption, and provides a biochemical explanation for the increase in bone mineralisation. Height standard deviation scores were not affected, and there were no significant adverse effects.

Conclusion: 18 months cyclical pamidronate is effective in improving bone mineralisation, and reducing fracture incidence in O.I. Pamidronate therapy, which was safe, and when combined with intra-medullary rodding, can potentially improve the quality of life by improving mobility and preventing post-fracture deformities, thus offering new hope for children afflicted with OI.