The Effects of High-Dose Parathyroid Hormone Treatment on Fusion Outcomes in a Rabbit Model of Posterolateral Lumbar Spinal Fusion Alone and in Combination with Bone Morphogenetic Protein 2 Treatment.

Background: Parathyroid hormone (PTH) (1-34) treatment reduces fracture risk in osteoporotic patients. Previously, we demonstrated in a rabbit model that low-dose PTH treatment resulted in increased fusion mass volume. As effects of PTH on bone are dose-dependent, we aimed to evaluate whether increasing dosage of PTH increases both volume and biomechanical stiffness of the resulting fusion masses and/or exhibits synergistic effects with low-dose bone morphogenetic protein 2 (BMP-2).