An update on bone substitutes for spinal fusion

Abstract

With the current advances in spinal surgery, an understanding of the precise biological mechanism of each bone substitute is necessary for inducing successful spinal fusion. In this review, the categories of bone substitutes include allografts, ceramics, demineralized bone matrix, osteoinductive factors, autogenous platelet concentrate, mesenchymal stem cells, and gene therapy. Further, clinical studies have been evaluated by their levels of evidence in order to elucidate the precise effect of the bone substitute employed and to establish clinical guidance. This article will review both clinical studies based on evidence and basic research in current advances in order to avoid as far as possible any chances of failure in the future and to understand cellular biology in novel technologies.

Development of a gene-activated scaffold platform for tissue engineering applications using chitosan-pDNA nanoparticles on collagen-based scaffolds

“…However, as rhBMP-2 has a very short half-life, supraphysiological amounts of rhBMP-2 must be delivered in order to be effective. This can have adverse effects [4]. The delivery of genes-encoding growth factors, rather than the protein itself, offers a means of controlling the expression of protein at the defect site and prolonging the timeline of expression without needing repeated doses.…”

Platelet-rich plasma in mono-segmental posterior lumbar interbody fusion

“…Manufacturers were therefore required to add a text to the warnings section of the device label, stating that the effectiveness of the device has not been established [31]. In a recent review article, platelet gel was given a grade 2B recommendation (weak recommendation; alternative approaches likely to be better) as an enhancer of the effect of autograft for both posterior lumbar fusion and anterior lumbar interbody fusion [30]. The grade of recommendation depended on the clarity of the risk/benefit and the methodological strength of supporting evidence.…”

Authors’ reply to the Letters to the Editor of T. Smoljanovic et al. concerning “An update on bone substitutes for spinal fusion”, Eur Spine J (2009) 18:783–799 by M. Miyazaki et al.

“…As Khan et al [1] state, large, prospective, and multicenter collaborative trials are important in clinical research. However, the literature is mainly composed of reviews and meta-analyses considering the difficulties in constructing the study type described.…”

“…The grade of evidence criteria used in our paper [1] was determined in reference to two articles published in JBJS Am and Spine [2,3]. As the authors state, there may be interobserver variation even when similar/same criteria are used.…”