THU0397 Efficacy of pamidronate in children with osteogenesis imperfecta: An open prospective study

Background Osteogenesis imperfecta (O.I) is a disorder characterized by osteopenia, frequent fractures, progressive deformity, and chronic bone pain. Its severity depends mainly on the severity of the bone lesions. Treatment with pamidronate has changed the pejorative natural evolution of this disease by reducing the fracture incidence. Objectives to assess the effects of treatment with pamidronate in children with moderate to severe (OI). Methods This is an uncontrolled open-label study in which were included 69 children who were 2 to 16 years old with moderate to severe OI and in whom at least two fractures occurred in the previous year. We administrated pamidronate intraveinously 1 mg of body weight per day for 3 days cyclically every 4 months, All patients received daily supplementation of calcium and vitamine D and physical rehabilitation. Efficiency is measured by the reduction of fracture after one year of treatment. In addition we measured the change in bone density and functional status, before and after treatment. SPSS 13.0 was used for the statistical analysis. Results The average age of the 69 children who completed one year of treatment was 6.26 (SD 3.80). The average annual number of radiologic confirmed fractures decrease by 3.59 [95% CI: 2.8 to 4.3]. Before treatment it was 4.71 (3.36) and was reduced to 1.11 (1.4). The average gain in BMD (available in 55 children) was 58.58 mg/cm2 [42.7 to 72.4], the percentage gain is 20% comparatively to baseline. The mean Bleck functional score increased in mean by 2 stages. Mobility and ambulation was improved according to Bleck score in 43 children who gained at less one stage The mean decrease of chronic bone pain assessed by VAS was 67%. We also assessed 39 children who completed two years of treatment, the fracture rate reduction in this sub-group was 79%. No adverse effect on growth or on fracture healing were observed. Post-infusion transient acute phase reaction and asymptomatic hypocalcaemia were observed. Conclusions cyclic administration of intravenous pamidronate In children with moderate and severe osteogenesis imperfecta decreased fracture rate, chronic bone pain, increased bone mineral density and improved clinical outcome. References Glorieux FH, Pettifor JM, Jupner H, editors. Pediatric Bone: Biology and Diseases. SanDiego: Academic Press; 2003. p.401-63. Forin V, Arabi A, Guigonis V, Filipe G, Bensman A, Roux C. Benefits of pamidronate in children with osteogenesis imperfecta: an open prospective study. Joint Bone Spine. 2005; 72: 313-8 Disclosure of Interest None Declared