Effect of treatment with alendronate in osteogenesis imperfecta type I: a case report

A case of osteogenesis imperfecta (OI), which was successfully treated with alendronate is reported. A 41-year-old premenopausal woman with OI type I, who had frequently been experiencing fragile fractures, consulted our clinic because of back pain associated with spinal osteoporosis. She had experienced heart surgery (aortic valve replacement) due to aortic regurgitation 5 years before her first consultation with our clinic. After the surgery, she had been taking warfarin 3 mg/day, and this treatment was continued during our follow-up period. She was treated with alendronate (5 mg/day, daily) for 18 months. The bone mineral density of the lumbar spine (L2-L4) measured by dual energy X-ray absorptiometry (Norland XR-36) increased for 18 months, and back pain markedly decreased. The urinary cross-linked N-terminal telopeptides of type I collagen and serum bone-specific alkaline phosphatase, osteocalcin, and undercarboxylated osteocalcin levels also markedly decreased. No new fragile vertebral or non-vertebral fractures were observed during the 18 months of treatment. This report provides evidence indicating that treatment with oral alendronate may have the potential to decrease bone turnover, improve the lumbar BMD, reduce back pain, and prevent new fragile fractures in premenopausal women with OI type I.