Bisphosphonates and parathyroid hormone analogs for improving bone quality in spinal fusion: State of evidence

Abstract

Spinal fusion is among the most commonly performed surgical procedures for elderly patients with spinal disorders – including degenerative disc disease with spondylolisthesis, deformities, and trauma. With the large increase in the aging population and the prevalence of osteoporosis, the number of elderly osteoporotic patients needing spinal fusion has risen dramatical-ly. Due to reduced bone quality, postoperative complications such as implant failures, fractures, post-junctional kyphosis, and pseudarthrosis are more commonly seen after spinal fusion in osteoporotic patients. Therefore, pharmacologic treatment strategies to improve bone quality are commonly pursued in osteoporotic cases beforecon-ducting spinal fusions. The two most commonly used pharmacotherapeutics are bis-phosphonates and parathyroid hormone (PTH) analogs. Evidence indicates that using bisphosphonates and PTH analogs, alone or in combination, in osteoporotic patients undergoing spinal fusion, decreases complication rates and improves clinical outcomes. Further studies are needed to develop guidelines for the administration of bisphosphonates and PTH analogs in osteo-porotic spinal fusion patients in terms of treatment duration, potential benefits of sequential use, and the selection of either therapeutic agents based on patient charac-teristics.