Seven studies were included in the review (n=168 patients); six were RCTs (n=144 patients) and one was a quasi-experimental study (n=24 patients). Five of the studies were rated fair and two were rated as poor. Follow-up varied between six and 24 months.
Acute spinal cord injury: Bone mineral density declined at a slower rate in patients given alendronate (70mg weekly), commencing within 10 days of spinal cord injury and continuing for 12 months. There was a 17.6% (p<0.001) difference in total hip bone mineral density and 7% (p<0.001) difference in total body leg bone mineral density between the intervention group and the control group. Patients receiving a single dose of 4 or 5mg of zoledronic acid at 10 to 12 weeks after spinal cord injury had attenuated bone loss at the proximal femur for six months and at the femur shaft for 12 months, although the effect at the proximal femur did not persist. In the group given etidronate, bone mineral density was maintained near baseline only in the two patients who were ambulatory. Patients receiving intravenous pamidronate also had attenuated bone mineral density loss, but this was not demonstrated to persist at 24 months.
Chronic spinal cord injury: Bisphosphonates use in chronic spinal cord injury improved bone mineral density loss relative to pre-treatment values, although statistical significance was only reported as achieved in two of nine bone mineral density parameters. In a study of patients with acute and chronic spinal cord injury given alendronate (10mg daily) plus elemental calcium for 24 months, there was a statistically significant treatment effect over those given calcium alone (distal tibia -2.0% versus -10.8%; p=0.017), but generally no reparation of bone loss relative to bone mineral density before spinal cord injury.