Bone Abstracts

Objectives: Childhood osteoporosis can be treated with i.v. bisphosphonates in order to improve bone mass and density. The aims of this study were to evaluate the safety and efficacy of 6-monthly zoledronic acid (ZA) in children with osteoporosis.

Methods: A retrospective cohort study of 27 patients (16 males and 11 females) were treated with 6-monthly ZA (0.05 mg/kg per dose) for a minimum of 1 year. Seventeen patients were immobile, 4 had steroid-induced osteoporosis, 2 had osteogenesis imperfecta, and 4 had other diagnoses. 16/27 (59%) had long bone fractures and 12/27 (44.4%) had vertebral wedging at baseline. Mineral homeostasis, bone mineral density by DXA and vertebral morphometry were evaluated at baseline and 1 year.

Results: The median age at commencement of treatment was 12.3 years (range 8–15.8). Following the first infusion, 2/27 (7%) and 1/27 (4%) developed asymptomatic hypocalcemia at 48 and 72 h respectively. A fever above 38 °C developed in 14/27 (52%), generalised aches/pains in 13/27 (48%) and nausea in 6/27 (22%). At 1 year there was a significant reduction in bone turnover and improvement in bone mineral density (BMD) (Table 1). Patients with vertebral wedging at baseline showed significant improvement in anterior, middle and posterior vertebral height ratios at 1 year. Only one patient fractured after starting ZA. There was normal growth.

Conclusion: Six-monthly ZA was associated with an acute phase reaction to the first dose and improvement in BMD, reduction in bone turnover and improved vertebral shape at 1 year.