Biomechanical Comparison of Vertebral Augmentation and Cement Discoplasty for the Treatment of Symptomatic Schmorl’s Node Combined With Modic Change: Finite Element Analyses

Abstract

Study design: Finite element simulation study.Objective: To compare the biomechanical effects of percutaneous vertebral augmentation (PVA) and percutaneous cement discoplasty (PCD) in patients with symptomatic Schmorl’s node combined with Modic change.Methods: CT data from a single patient was assembled into finite element models, from which we constructed four distinct surgical models, including PVA-ideal, PVA-nonideal, PCD-ideal, and PCD-nonideal, to compare the stress and strain differences of parapodular tissues.Results: The validity of our model was confirmed. PVA-ideal model showed a moderate reduction in the stress peak of the Schmorl’s node (0.48 vs. 0.81–0.89 Mpa) in the erect position. In the PCD-ideal model, the stress peak of the Schmorl’s node increased significantly when the spine was moved toward the lesion (3.99Mpa). Both PVA-ideal and PCD-ideal models showed global strain inhibition at the Schmorl’s node and BMEZ, which was attenuated in the non-ideal models. The PCD-ideal model significantly reduced segmental ROM (-76.8% to -59.3%) and significantly increases endplate stress (up to 220.8%), with no such effects seen in the PVA-ideal model.Conclusions: Both PVA-ideal and PCD-ideal models facilitated a more stable parapodular biomechanical microenvironment. The PVA-ideal model yielded minimal stress disturbance on the augmented or adjacent vertebral endplate but offered no improvement to segment stability. The PCD-ideal model provides adequate segment stability, but also carries a greater risk for adjacent vertebral fracture. As nonideal implementations of both surgeries can result in poor biomechanical outcomes, the surgical indications of PVA or PCD need to be carefully selected.