Facet joint fusion in lumbar surgery: a biomechanical review of posterior column preservation and reconstruction.

Adjacent segment disease (ASD) is a multifactorial long-term complication of lumbar interbody fusion. In addition to patient-related factors, pre-existing degeneration, sagittal alignment, and fusion-related changes in construct stiffness, iatrogenic disruption of the posterior elements may contribute to altered adjacent-segment biomechanics. The role of the facet joint complex in this process has received comparatively limited attention. This narrative review synthesizes biomechanical, cadaveric, and clinical evidence concerning lumbar facet arthrodesis, posterior-column preservation and reconstruction, and two-column fixation after lumbar interbody fusion. Biomechanical studies suggest that preservation of the posterior ligamentous and facet structures can influence segmental stability, load sharing, and adjacent-level intradiscal or facet stresses. Facet-based fixation provides rotational constraint under experimental conditions and may offer a different stiffness profile from conventional pedicle screw constructs. The potential role of facet arthrodesis appears to depend on the extent of posterior-element disruption, residual instability, and the stability requirements of the overall construct. Current evidence is insufficient to recommend its routine use after TLIF or PLIF or to conclude that it reduces symptomatic ASD, reoperation rates, or improves long-term patient-reported outcomes. Prospective clinical studies with long-term follow-up are required.