Bone Abstracts

Objectives: Quadriplegic children are more susceptible to osteoporosis because of various risk factors for the inhibition of bone metabolism. The importance of bone metabolism is being emphasized based on extending life span of the patients but research on this area is insufficient. Intravenous (IV) pamidronate is well known as an effective treatment for pediatric osteoporosis, but there are no treatment guidelines for accurate dose capacity and duration in quadriplegic children with osteoporosis. We aimed to evaluate the efficacy of low doses of IV pamidronate in those patients.

Methods: Nine quadriplegic patients (6 male, 3 female; mean age 10.6±6.0) who were taking antiepileptic drug in one institution were treated with pamidronate (0.25–1.0 mg/kg/d, 2 consecutive days) every 8–12 weeks. The patients were receiving calcium and vitamin D before the treatment. BMD Z-score, blood and urine biochemical markers of bone metabolism were measured periodically before and during treatment.

Results: All patients were quadriplegic state graded at Level V using gross motor function classification system. The main underlying disease was perinatal hypoxic brain damage (44.4%, 4/9). The mean cumulative dose of IV pamidronate was 3.39±1.08 mg/kg/year, and the mean treatment period was 12.0±6.36 months. There was significant increase in BMD Z-score of the lumbar spine after the treatment. (from −4.01±1.26 to −2.35±1.53, P=0.018). Urine NTX (cross-linked N-terminal telopeptide of type I collagen) and alkaline phophatase were significantly decreased during treatment (P<0.05). 55.5% (5/9) of them experienced a fracture before treatment, but no fracture occurred after treatment. No significant adverse effects were observed.

Conclusion: Low dose of IV pamidronate therapy improved BMD of lumbar spine and biochemical markers of bone metabolism in quadriplegic children with osteoporosis. Appropriate guidelines including the optimal dose and duration are required for t.

Disclosure: The authors declared no competing interests.