The Efficacy of Zoledronic Acid in the Prevention of Bone Loss in Acute Spinal Cord Injury

Immobilization is associated with disuse osteoporosis. Spinal cord injury (SCI) produces a syndrome of acute skeletal immobilization with immediate and irreversible unloading of the involved skeletal regions resulting in accelerated bone loss. In addition to rapid bone loss, there are also the complications of hypercalciuria, hypercalcemia, nephrolithiasis, and renal insufficiency. In some reports, as much as 50% of regional bone mass has been lost within the first year after paralysis. A depletion of regional bone of such magnitude greatly increases the risk of fractures, with associated morbidity and increased cost of care. Often, these fractures occur with minimal or non-obvious trauma and may pass undiagnosed for varying lengths of time due to the absence of pain sensation. The acute complications of fracture may include hemorrhage, deep venous thrombosis, and autonomic dysreflexia. Long-term complications include functional deformity, non-union, infection, heterotopic calcification, and significantly longer healing time. The sociology-economic consequences include a minimum of 1 to 2 weeks of hospitalization and the potential need for an increased level of attendant care. This study will address the efficacy of a bisphosphonate, zoledronic acid (Reclast: 5 mg; Novartis Pharmaceuticals Inc., East Hanover, NJ), in the prevention of the bone loss associated with acute SCI.

Prevention of regional osteoporosis in persons with SCI would reduce the morbidity associated with fractures, a known secondary complication of immobilization. Thus, the quality of life would be improved in terms of employment responsibilities (reduction in days absent from employment and income lost) and personal activities (recreational endeavors, independence, and ease in which one performs activities of daily living). Individuals with SCI may then engage more securely in activities without fear of fracture, a tremendous psychological benefit.