Biologic Augmentation in Lumbar Spinal Fusion: A Systematic Review of Recombinant Bone Morphogenetic Protein-2, Mesenchymal Stem Cells, and Platelet-Rich Plasma

Abstract

Achieving solid arthrodesis remains a key challenge in lumbar spinal fusion, particularly in patients at increased risk of pseudarthrosis. Biologic augmentation has been introduced to enhance fusion biology; however, its clinical value remains incompletely defined. To systematically review the clinical evidence on biologic augmentation in adult lumbar spinal fusion, focusing on radiographic fusion, clinical outcomes, and safety. A systematic search of PubMed, the Cochrane Library, and ScienceDirect was conducted in accordance with PRISMA guidelines. Comparative clinical studies evaluating rhBMP-2, mesenchymal stem cells, or platelet-rich plasma in lumbar fusion were included. Data were synthesized qualitatively because of clinical and methodological heterogeneity. Six studies met the inclusion criteria. Biologic augmentation was consistently associated with higher fusion rates or faster radiographic fusion compared with conventional grafting methods. However, improvements in patient-reported outcomes, including pain and functional scores, were generally comparable between the biologic and control groups. Complication rates were also similar, with no consistent safety concerns directly attributable to the biologic agents. The findings suggest that biologic augmentation primarily enhances fusion biology rather than clinical recovery. Differences among biologic agents reflect distinct mechanisms of action and may influence the timing of fusion rather than long-term outcomes. Biologic augmentation improves radiographic fusion in lumbar spinal surgery but does not consistently improve clinical outcomes. Careful patient selection and further high-quality trials are warranted.