Cobetto Nikita, Fecteau Marie-Ève, Caouette Christiane, Gay Marine, Larson A Noelle, Hoernschemeyer Dan, Boeyer Melanie, El-Hawary Ron, Alanay Ahmet, Aubin Carl-Eric
Department of Mechanical Engineering, Downtown Station, Polytechnique Montréal, P.O. Box 6079, Montreal, QC, Canada.
Research Center, Sainte-Justine University Hospital Center, Montreal, QC, Canada.
Spine Deform. 2025 Jun 8. doi: 10.1007/s43390-025-01123-x.
Vertebral body tethering (VBT) for lumbar curves may have wider application than for thoracic curves due to greater growth potential than thoracic spine and benefits of preserved flexibility. Predicting long-term correction remains challenging, with high revision rates and complications (14-32%) including under-/over-correction, tether breakage, adding-on. This study aimed to validate a planning tool for lumbar VBT using a patient-specific finite element model (FEM) integrating mechanobiological growth modulation as a function of preoperative skeletal maturity.
Thirty-five retrospective idiopathic scoliosis patients who underwent lumbar VBT, with or without concomitant thoracic VBT, were included. A personalized FEM calibrated to preoperative spine deformity, flexibility and weight was created using 3D radiographic reconstructions. The FEM was linked to an algorithm integrating spine growth and mechanobiological growth modulation, calibrated using preoperative Sanders score. VBT surgery was simulated to replicate immediate postoperative correction and predict two-year correction. Simulated Cobb angles, sagittal curves, and apical axial rotation were compared to actual two-year radiographic measurements.
Preoperative Cobb angles averaged 37 ± 12° (thoracic) and 48 ± 9° (thoraco-lumbar/lumbar). Immediate postoperative correction was 38 ± 15% and 59 ± 16%, with two-year corrections of 44 ± 24% and 73 ± 21%, respectively. Simulated postoperative correction was accurate within 3° (Cobb angles), while simulated 2-year outcomes were accurate within 3° (Cobb), 2° (kyphosis), 4° (lordosis), and 3° (axial rotation), showing no significant differences from reference results (p < 0.05; statistical power 90%).
The patient-specific FEM and growth modulation algorithm accurately predicted two-year correction. This tool can support preoperative planning, reduce surgeon variability, and potentially improve VBT outcomes by providing a predictive tool to help surgical planning.
由于腰椎曲线的生长潜力大于胸椎曲线，且保留灵活性有益处，椎体牵张术（VBT）在腰椎曲线中的应用可能比在胸椎曲线中更广泛。预测长期矫正仍然具有挑战性，翻修率和并发症较高（14 - 32%），包括矫正不足/过度、牵索断裂、附加畸形。本研究旨在使用整合了作为术前骨骼成熟度函数的机械生物学生长调节的患者特异性有限元模型（FEM）来验证一种用于腰椎VBT的规划工具。
纳入35例接受腰椎VBT（伴或不伴胸椎VBT）的回顾性特发性脊柱侧凸患者。使用三维放射学重建创建一个根据术前脊柱畸形、灵活性和体重校准的个性化FEM。该FEM与一个整合脊柱生长和机械生物学生长调节的算法相连，该算法使用术前桑德斯评分进行校准。模拟VBT手术以复制术后即刻矫正并预测两年矫正情况。将模拟的 Cobb角、矢状曲线和顶椎轴向旋转与实际两年的放射学测量结果进行比较。
术前Cobb角平均为37±12°（胸椎）和48±9°（胸腰段/腰椎）。术后即刻矫正分别为38±15%和59±16%，两年矫正分别为44±24%和73±21%。模拟的术后矫正在3°（Cobb角）范围内准确，而模拟的两年结果在3°（Cobb角）、2°（后凸）、4°（前凸）和3°（轴向旋转）范围内准确，与参考结果无显著差异（p < 0.05；统计效能90%）。
患者特异性FEM和生长调节算法准确预测了两年矫正情况。该工具可支持术前规划，减少外科医生的差异，并通过提供一种有助于手术规划的预测工具潜在地改善VBT结果。
