title: Pharmacophysiology of bone and spinal fusion.
abstract: BACKGROUND
  In recent years, the number of complex spinal surgeries has increased significantly in the elderly population, where the prevalence of low bone density is highest. Consequently, spine surgeons often treat osteoporotic patients who are associated with higher rates of instrumentation failure. Therefore, establishing a successful fusion requires an appropriate substrate for bone formation and local bone remodeling. The fusion process can be supported by therapies that seek to shift the balance of bone homeostasis to increased formation and reduced resorption.
  
  
  OBJECTIVE
  Thorough understanding of the physiology of bone formation and adjunctive therapies can help improve fusion rates. Therefore, we present a thorough review of the latest pharmacologic agents used to enhance bone strength and surgical spinal fusion.
  
  
  METHODS
  Systematic review of literature.
  
  
  RESULTS
  Current knowledge on bone physiology has led to the development of several pharmacologic agents that enhance bone formation and strengthen the human skeleton. At present, natural supplements of vitamin D and calcium or synthetic medications like bisphosphonates are widely used before and after spine surgeries to enhance bone fusion. Additional physiologic agents, including testosterone, parathyroid hormone, calcitonin, and growth hormone, have been shown to improve bone mass density or spinal fusion in both animal and human studies. As in other medical fields, gene therapy has shown viability and promise with the use of both viral and nonviral vectors.
  
  
  CONCLUSIONS
  Through the understanding of bone physiology, numerous natural and synthetic pharmacologic agents have been developed to enhance the body's skeleton and to improve outcomes of spinal fusion surgery.
authors: Division of Neurological Surgery, Barrow Neurological Institute, St Joseph's Hospital and Medical Center, 350 W. Thomas Rd, Phoenix, AZ 85013, USA.
authors: Samuel
authors: S
authors: Kalb
authors: Mark A
authors: MA
authors: Mahan
authors: Ali M
authors: AM
authors: Elhadi
authors: Alexander
authors: A
authors: Dru
authors: Justin
authors: J
authors: Eales
authors: Marcelo
authors: M
authors: Lemos
authors: Nicholas
authors: N
authors: Theodore
mesh_terms: D000818:Animals; D015519:Bone Density / Q000187:drug effects; D050071:Bone Density Conservation Agents / Q000494:pharmacology*; D001842:Bone and Bones / Q000187:drug effects* / Q000503:physiopathology*; D006801:Humans; D010012:Osteogenesis / Q000187:drug effects; D013123:Spinal Fusion / Q000379:methods*
chemical_list: D050071:Bone Density Conservation Agents
keywords: Bone; Fusion; Medications; Physiology; Spine