Patients who sustain an acute spinal cord injury (SCI) experience rapid, dramatic reductions in bone mineral density (BMD) especially marked in sublesional areas and sometimes leading to hypocalcaemia and hypercalciuria as well as increased fracture risk.
In this prospective, double-blind, randomized, placebo-controlled study researchers evaluated the hypothesis that oral alendronate administration would preserve BMD when administered soon after acute SCI. Thirty one patients with acute SCI were randomly allocated to receive oral alendronate 70 mg weekly or placebo, within 10 days of acute SCI, for 12 months. At entry, 3, 6, 12 and 18 months, total body bone density, lumbar and hip BMD, ultrasound of the calcaneous, 24 hour urinary calcium and serum C-teleopeptide (Beta CTX) were measured. At study entry patients in the two groups were well matched for age, gender, severity of neurologic deficit, BMD, urinary calcium and B-CTX. BMD indices declined steadily in the placebo group and this effect was attenuated significantly by alendronate: after 12 months there was a 5.3% difference (P < 0.001) in total body BMD and 17.6% difference (P < 0.001) in the total hip BMD between the two groups. Alendronate compared with placebo induced significant (P < 0.001) reductions in urinary calcium excretion and serum B-CTX. No treatment related side effects were noted. Researchers concluded that alendronate therapy, 70mg per week, initiated soon after acute SCI, prevents bone loss and is not associated with side effects.(Source: The Journal of Clinical Endocrinology and Metabolism : Canterbury Geriatric Medical Research Trust, The Princess Margaret Hospital, Christchurch, New Zealand; Department of Medicine, Christchurch School of Medicine and Health Sciences, Christchurch, New Zealand; Spinal Unit, Burwood Hospital, Christchurch, New Zealand : January 2007.)