Grafting Strategies in Spine Surgery - Bone Graft in Spine Surgery

Abstract
 
Spinal arthrodesis depends on bone grafting strategies that balance biology, safety, handling, and cost across autograft, allograft, demineralized bone matrix, synthetic substitutes, and orthobiologic enhancers. [3,5]
Autologous iliac crest bone graft remains the historical reference standard because it combines osteoconduction, osteoinduction, and osteogenesis in one material. [3,4]
Donor-site morbidity, limited harvest volume, and operative burden have driven broader use of local autograft, allograft, ceramics, and biologic enhancers such as recombinant human bone morphogenetic protein-2. [3,4,9]
Published systematic reviews suggest that no single substitute is universally superior across every fusion setting, and the quality of evidence varies substantially by product class and indication. [6,5,7]
 
Introduction
Spinal fusion is performed to achieve a stable bony union between vertebrae in conditions such as deformity, instability, trauma, and selected degenerative disorders. [10,11]
Bone graft in spine surgery  is used to support new bone formation across the intended fusion bed and remains central to successful arthrodesis. [10,3]
Historical reviews trace the development of modern spine grafting from early autograft techniques to the current use of allografts, synthetics, and osteobiologics. [4]
Contemporary graft selection therefore reflects both biologic principles and the practical need to reduce morbidity while maintaining fusion reliability. [3,7]
 
Biology of Spinal Fusion
Successful fusion requires a graft environment that supports osteoconduction, osteoinduction, and osteogenesis. [3,7]
Osteoconduction provides the scaffold for bone ingrowth, osteoinduction recruits and stimulates progenitor cells, and osteogenesis depends on viable bone-forming cells within the graft. [3]
Because no alternative material reproduces these properties equally in every setting, graft choice is often based on which biologic functions must be supplemented for a given patient and procedure. [3,6]

Autograft - Bone Graft in Spine Surgery
Iliac crest autograft has long been considered the benchmark for spinal fusion because of its complete biologic profile and extensive clinical history. [3,4]
Its main drawbacks are donor-site pain and other harvest-related complications, which are major reasons alternative strategies have been pursued. [4,12]
Local autograft harvested during decompression or osteotomy can reduce harvest morbidity and has shown strong fusion performance in pooled analyses when adequate quantity and quality are available. [5,7]
 
Allograft and DBM
Allograft eliminates donor-site morbidity and provides an osteoconductive framework, which explains its broad use in cervical and structural fusion procedures. [3,6]
However, processing reduces cellular viability, and incorporation may be less biologically active than with autograft. [3,6]
Demineralized bone matrix can add osteoinductive potential, but published outcomes vary by formulation, carrier, and surgical indication, limiting broad comparative conclusions. [3,8]
 
Synthetic Grafts and Biologics
Synthetic grafts such as calcium phosphate ceramics and related scaffold materials are commonly used to extend autograft or replace volume in selected fusion settings. [6,7]
Systematic reviews indicate that many of these materials can achieve acceptable fusion outcomes, but the evidence base is heterogeneous and often limited by bias. [6,7]
Recombinant human BMP-2 has shown strong fusion efficacy in lumbar fusion analyses, yet the literature also emphasizes the need for caution because adverse events are procedure-specific and can be clinically important. [8,9]
 
Emerging Strategies
More recent grafting approaches include cell-based grafts, composite matrices, and engineered scaffolds designed to combine scaffold, signaling, and cellular activity. [13,14]
These technologies are promising, but comparative evidence remains less mature than for traditional autograft and established substitutes. [13,14]
Reviews of newer orthobiologics consistently call for higher-quality trials and longer follow-up before routine superiority claims can be justified. [13,14]
 
Clinical Selection
The literature supports individualized graft selection based on fusion level, number of segments, mechanical demands, revision status, host biology, and nonunion risk factors. [3,7]
Local autograft is attractive when adequate bone is available, whereas structural allograft, demineralized bone matrix, ceramics, or biologic enhancers may be added when more volume, mechanical support, or osteoinductive stimulus is needed. [3,6,8]
In practice, the best grafting strategy is usually a procedure-specific combination rather than a single universal material. [3,7]
 
Disclaimer
This article is intended solely for scientific and educational purposes and does not constitute medical advice, product labeling, or promotional claims. [3,10]
Some products discussed in the literature may be FDA-cleared or FDA-approved only for specific indications, and other uses described in published studies may be investigational or off-label. [3,9]
Clinicians are responsible for consulting current labeling, instructions for use, institutional requirements, and applicable law before selecting any graft or biologic product. [3]
Published fusion and complication outcomes vary according to patient factors, operative technique, graft composition, fixation, and follow-up, so no statement in this article should be interpreted as a guarantee of clinical outcome. [5,7,8]
 
References
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2. Katsuura Y, Hofstetter CP, Sharan A, et al. New strategies in enhancing spinal fusion. Surg Technol Int. 2020.
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4. Hampel GA, Theologis AA. History of bone grafts in spine surgery. Neurospine. 2022;19(2):379-391.
5. Tavares WM, de França SA, Paiva WS, Teixeira MJ. A systematic review and meta-analysis of fusion rate enhancements and bone graft options for spine surgery. Sci Rep. 2022;12(1):7546.
6. Campana V, Milano G, Pagano E, et al. Spinal fusion procedures in the adult and young population: a systematic review on allogenic bone and synthetic grafts when compared to autologous bone. J Mater Sci Mater Med. 2020;31:75.
7. Steinberger J, Qureshi S, Szerlip B, et al. Bone graft materials for posterolateral fusion made simple: a systematic review. Eur Spine J. 2018;27(8):1856-1867.
8. Liu S, Wang Y, Liang Z, et al. Efficacy and safety of bone substitutes in lumbar spinal fusion: a systematic review and network meta-analysis of randomized controlled trials. Eur Spine J. 2020;29(6):1261-1276.
9. Feng C, Wang H, Tang Y, et al. A meta-analysis of lumbar spinal fusion surgery using bone morphogenetic proteins and autologous iliac crest bone graft. PLoS One. 2014;9(6):e97049.
10. OrthoInfo. Bone grafts in spine surgery. American Academy of Orthopaedic Surgeons.
11. OrthoInfo. Spinal fusion. American Academy of Orthopaedic Surgeons.
12. American Academy of Orthopaedic Surgeons. Tips and tricks in harvesting of bone from the iliac crest.
13. Iliac crest bone graft versus cell-based grafts to augment spinal fusion: a systematic review and meta-analysis. Eur Spine J. 2024.
14. Efficacy of using autologous cells with graft substitutes for spinal fusion surgery: a systematic review and meta-analysis of clinical outcomes and imaging features. 2024.