Bone Abstracts

Background: Intravenous (IV) bisphosphonate (BP) is used for treatment of painful vertebral fractures (VF) in children with underlying chronic conditions. BP effect on vertebral height reshaping in this population is however poorly studied.

Aims/Objectives: To evaluate the impact of IV BP on vertebral morphometry in children with VF and underlying chronic medical conditions with associated glucocorticoid (GC) therapy.

Methods: Retrospective study of eight children (6M) with VF treated with IV BP for 1–2 years: 5 Duchenne Muscular Dystrophy (DMD), 2 Crohn’s Disease (CD), 1 Juvenile Dermatomyositis (JDM). Vertebral height from lateral spine x-rays (T10-L5) were measured on two occasions by one single observer (JT). Repeatability co-efficient of vertebral height ratios were determined. Improvement and deterioration in vertebral height ratio was considered to be significant if changes exceeded the 99% confidence level of the repeatability co-efficient at a particular vertebral level and also changed Genant staging. Results presented as median (range).

Results: Median age at baseline was 12.2 years (5.6, 17.0). Height SDS at baseline was −2.4 (−3.4, −1.4), significantly lower than height SDS a year prior to commencement of therapy, −1.5 (−2.7, −0.8) (P=0.0009) but did not improve following BPs −2.5 (−4.9, 0.2) (P=0.87). All eight were on GC at baseline but only 5/8 were on GC at last follow-up. Lumbar spine bone mineral content SDS for bone area at start was −0.9 (−2.8, 1.9) and did not change with BP, −0.4(−1.7, 1.6) (P=0.08). Vertebral height ratio improved in 3/8 children (2 DMD, 1 CD) in 6 vertebrae (2 DMD, 1 CD). Vertebral height ratio decreased in 3/8 children (2 DMD, 1 CD) in 8 vertebrae. One boy with DMD who showed deterioration of vertebral height ratio also sustained fracture femur during BP therapy. Four out of the 8 (3 DMD, 1 JDM) had stabilization of vertebral height ratio with therapy.

Conclusion: Intravenous bisphosphonates in children with chronic disease and vertebral fracture led to stabilization in vertebral height in half of the cohort and improvement in vertebral height in some children but did not prevent the development of new VFs.

Disclosure: The authors declared no competing interests.