Zoledronate Increases Bone Mineral Density in Nonambulant Children With Cerebral Palsy: A Randomized Controlled Trial

Context Zoledronate appears to reduce fracture rates in children with cerebral palsy (CP), but no previous randomized, controlled trial has been performed to compare the effect of zoledronate to placebo in children with CP. Objective To investigate the effect of zoledronate on bone mineral density (BMD) Z-scores in children with nonambulant CP in a randomized, controlled, double-blind trial. Methods Nonambulant children with CP (5 to 16 years of age) were randomized 1:1 to receive 2 doses of zoledronate or placebo at a 6-month interval. BMD Z-score changes at the lumbar spine and the lateral distal femur (LDF) were calculated from dual-energy x-ray absorptiometry scans. Monitoring included weight, bone age, pubertal staging, knee-heel length, adverse events, biochemical markers, and questionnaires. Results Twenty-four participants were randomized and all completed the study. Fourteen were assigned to zoledronate. The mean lumbar spine BMD Z-score increased 0.8 SD (95% CI: 0.4; 1.2) in the zoledronate group, which was significant when compared to 0.0 SD (95% CI: -0.3; 0.3) in the placebo group. Similarly, the LDF BMD Z-scores increased more in the zoledronate group. Severe acute phase symptoms affected 50% of the patients in the zoledronate group but were reported exclusively after the first dose. Growth parameters were similar in both groups. Conclusion Zoledronate for 12 months increased BMD Z-scores significantly without affecting growth, but first-dose side effects were common and considerable. Studies into lower first doses and long-term outcomes are needed.