Current Updates on Bone Grafting Biomaterials and Recombinant Human Growth Factors Implanted Biotherapy for Spinal Fusion: A Review of Human Clinical Studies

Background: Owing to their great promise in the spinal surgeries, bone graft substitutes have been widely investigated for their safety and clinical potential. By the current advances in the spinal surgery, an understanding of the precise biological mechanism of each bone graft substitute is mandatory for upholding the induction of solid spinal fusion. Objective: The aim of the present review is to critically discuss various surgical implications and level of evidence of most commonly employed bone graft substitutes for spinal fusion. Method: Data was collected via electronic search using “PubMed”, “SciFinder”, “ScienceDirect”, “Google Scholar”, “Web of Science” and a library search for articles published in peer-reviewed journals, conferences, and e-books. Results: Despite having exceptional inherent osteogenic, osteoinductive, and osteoconductive features, clinical acceptability of autografts (patient’s own bone) is limited due to several perioperative and postoperative complications i.e., donor-site morbidities and limited graft supply. Alternatively, allografts (bone harvested from cadaver) have shown great promise in achieving acceptable bone fusion rate while alleviating the donor-site morbidities associated with implantation of autografts. As an adjuvant to allograft, demineralized bone matrix (DBM) has shown remarkable efficacy of bone fusion, when employed as graft extender or graft enhancer. Recent advances in recombinant technologies have made it possible to implant growth and differentiation factors (bone morphogenetic proteins) for spinal fusion. Conclusion: Selection of a particular bone grafting biotherapy can be rationalized based on the level of spine fusion, clinical experience and preference of orthopaedic surgeon, and prevalence of donor-site morbidities.