Zoledronic Acid in Non-Ambulatory Children and Young Adults with Fragility Fractures and Low Bone Mass Associated with Spastic Quadriplegic Cerebral Palsy and Other Neuromuscular Disorders

Abstract

Non-ambulatory patients with neurological disorders such as spastic quadriplegic cerebral palsy often have low bone mineral density (BMD) and fragility fractures from disuse osteoporosis. Limited data exists on zoledronic acid (a third generation bisphosphonate) treatment in the pediatric population. We report a case series of 10 patients with spastic quadriplegic cerebral palsy (n=6), spinal muscular atrophy (n=2), and myelomeningocele (n=2) treated with zoledronic acid for fragility fractures and/or low BMD associated with the underlying conditions. The clinical and BMD outcomes were retrospectively studied and compared with a historical cohort of 32 patients treated with intravenous pamidronate. Mean lumbar BMD increased significantly ( P < 0.01) by 28% at1 yearin zoledronic acid group, and by 19% in pamidronate group. Mean lumbar BMD weight-adjusted Z-scores improved from -4.31 at baseline to -2.55( P =0.003) at 1 year in zoledronic group, and from -3.66 to -2.30 in pamidronate group ( P =0.001). Total number of fractures in the zoledronic group was 18 before treatment and reduced to zero after treatment with an average follow-up of 3.9 years. All patients tolerated zoledronic acid infusion with fever in 3 patients (30%) during the initial infusion and nohypocal cemianoted during the treatment cycles. Treatment with zoledronic acid is safe, significantly improves bone density and reduces fractures in children and young adults with fragility fractures and low bone mass secondary to neuromuscular disorders. Further follow up studies are needed to confirm safety and efficacy in long-term fracture prevention.