Comparing the osteogenesis outcomes of different lumbar interbody fusions (A/O/X/T/PLIF) by evaluating their mechano-driven fusion processes

• Published in: Computers in biology and medicine 2024-03, Vol.171, p.108215, Article 108215
• Main Authors: Lu, Teng, Sun, Zhongwei, Xia, Huanhuan, Qing, Jie, Rashad, Abdul, Lu, Yi, He, Xijing
• Format: Article
• Language: English
• Subjects: Algorithms; Allografts; Apoptosis; Biomechanics; Bone grafts; Bone growth; Bone marrow; Cages; Cartilage; Cell differentiation; Chondrocytes; Extracellular matrix; Fibroblasts; Finite element; Finite element method; Grafting; Humans; Interbody cage; Intervertebral discs; Iterative methods; Lumbar interbody fusion; Lumbar Vertebrae - surgery; Lumbosacral Region; Mathematical analysis; Mechano-regulation; Mesenchymal stem cells; Osteoblastogenesis; Osteoblasts; Osteogenesis; Regeneration; Regeneration (physiology); Shear strain; Skin & tissue grafts; Spinal Fusion - adverse effects; Spinal Fusion - methods; Stem cells; Tissue engineering; Vertebrae
• ISSN: 0010-4825; 1879-0534; 1879-0534
• DOI: 10.1016/j.compbiomed.2024.108215

In lumbar interbody fusion (LIF), achieving proper fusion status requires osteogenesis to occur in the disc space. Current LIF techniques, including anterior, oblique, lateral, transforaminal, and posterior LIF (A/O/X/T/PLIF), may result in varying osteogenesis outcomes due to differences in biomechanical characteristics. A mechano-regulation algorithm was developed to predict the fusion processes of A/O/X/T/PLIF based on finite element modeling and iterative evaluations of the mechanobiological activities of mesenchymal stem cells (MSCs) and their differentiated cells (osteoblasts, chondrocytes, and fibroblasts). Fusion occurred in the grafting region, and each differentiated cell type generated the corresponding tissue proportional to its concentration. The corresponding osteogenesis volume was calculated by multiplying the osteoblast concentration by the grafting volume. TLIF and ALIF achieved markedly greater osteogenesis volumes than did PLIF and O/XLIF (5.46, 5.12, 4.26, and 3.15 cm3, respectively). Grafting volume and cage size were the main factors influencing the osteogenesis outcome in patients treated with LIF. A large grafting volume allowed more osteoblasts (bone tissues) to be accommodated in the disc space. A small cage size reduced the cage/endplate ratio and therefore decreased the stiffness of the LIF. This led to a larger osteogenesis region to promote osteoblastic differentiation of MSCs and osteoblast proliferation (bone regeneration), which subsequently increased the bone fraction in the grafting space. TLIF and ALIF produced more favorable biomechanical environments for osteogenesis than did PLIF and O/XLIF. A small cage and a large grafting volume improve osteogenesis by facilitating osteogenesis-related cell activities driven by mechanical forces. •The fusion processes of current LIF techniques were visualized using a mechano-regulation algorithm.•TLIF and ALIF yielded greater osteogenic volumes than did PLIF and O/XLIF.•Both the cage size and grafting volume play crucial roles in the osteogenic outcome of LIF.•A small cage and a large grafting volume facilitate osteogenic activities driven by mechanical forces.