Do Cellular Allografts Improve Spinal Fusion Enough to Justify Their Cost and Potential Risk? A Systematic Review of Efficacy, Safety, and Cost

BACKGROUND AND OBJECTIVES: Cellular bone allografts, developed to provide osteogenic properties similar to autologous bone graft without donor site morbidity, are increasingly used in spinal fusion surgery; however, their clinical efficacy, safety, and cost-effectiveness relative to cell-free alternatives remain incompletely defined. Therefore, we sought to systematically review the clinical evidence on cellular bone allografts in spinal fusion, specifically evaluating fusion rates, complications, and cost. METHODS: A Preferred Reporting Items for Systematic Reviews and Meta-Analyses-compliant systematic review of PubMed/Embase databases was conducted for English-language studies published between 2010 and 2025, evaluating cellular bone allografts in human spinal fusion. Studies reporting fusion outcomes in cervical and/or lumbar spine were included. Data were extracted on study design, cohort size, imaging modality used for fusion assessment, fusion rates, complications, and costs. Cervical and lumbar fusion outcomes were analyzed separately. Graft products were also evaluated individually. Publicly reported disease transmission events were also reviewed. RESULTS: Of 643 studies identified, 22 met the inclusion criteria (cervical: 9, lumbar: 12, combined cervical/lumbar: 1). No randomized controlled trials were identified. Reported fusion rates were high and ranged from 90.0% to 98.5% in the cervical spine and 82.0% to 100.0% in the lumbar; however, cohort sizes varied widely, and fusion assessment methods were heterogeneous, with many studies relying on a single imaging modality. No study demonstrated a statistically significant improvement in fusion rates compared with cell-free allografts or other graft controls. Reported graft-related complications were rare in clinical studies although 2 widely reported tuberculosis outbreaks linked to contaminated cellular allografts underscore persistent safety concerns. Limited cost data indicate that cellular allografts are substantially more expensive than cell-free alternatives but less costly than recombinant human bone morphogenetic protein-2. CONCLUSION: Although cellular bone allografts demonstrate high reported fusion rates, current evidence does not establish clinical superiority over cell-free allografts. Methodological heterogeneity, limited cohort sizes, safety considerations, and higher costs highlight the need for larger, rigorously designed comparative studies to define their true clinical value.