Oral bisphosphonate treatment for osteogenesis imperfecta - an Indian perspective

Background: Various treatments for the management of osteogenesis imperfecta (01) have been tried, of which bisphosphonates seem to have the maximum benefit in reducing fracture rate and improving bone density. This study investigated the value of oral alendronate for treating 01 in Indian children. Methods: Between 2002 and 2005, 11 patients with 01 were referred for bisphosphonate therapy. The various types of 01 were classified using the Sillence criteria. All patients underwent baseline biochemistry, radiographic studies and bone mineral density (BMD) measurements before commencing therapy. Patients were commenced on oral alendronate (0.5 mg/kg/day) and followed up for a period ranging from 1 month to 2 years. A retrospective analysis of pre- and post-treatment changes in fracture rate and bone density was undertaken using the paired sample t-test. Results: One patient lost to follow-up was excluded from the study and three completed only 2 months of therapy. Pretreatment fracture rate per year before treatment ranged from 0.5 to 6 with a mean (SD) of 2.95 (1.57) and median of 2.5. The post-treatment fracture rate was 1.1 (0.59)/year (p = 0.02). Seven children underwent BMD analysis while on treatment and all had a rise in BMD, of which the change in lumbar spine BMD was statistically significant (p = 0.001), and lumbar (p = 0.005) and femoral neck t-score (p = 0.04) showed a significant change. No significant change was seen in serum biochemistry except for disappearance of hypercalciuria (p = 0.04). No child had an adverse reaction to alendronate. Conclusion: After a median of 9.5 months of treatment, oral alendronate is associated with a lower fracture rate, improvement in BMD and a decrease in hypercalciuria.