Salvi Giuditta, Aubin Carl-Eric, Le Naveaux Franck, Wang Xiaoyu, Parent Stefan
Department of Mechanical Engineering, Polytechnique Montreal, P.O. Box 6079, Downtown Station, Montreal, QC, H3C 3A7, Canada.
Research Center, Sainte-Justine University Hospital Center, 3175, Cote Sainte-Catherine Road, Montreal, QC, H3T 1C5, Canada.
Eur Spine J. 2016 Aug;25(8):2452-60. doi: 10.1007/s00586-015-4279-1. Epub 2015 Oct 14.
Biomechanical analysis of Ponte (PO) and pedicle subtraction osteotomies (PSO) in kyphotic deformity instrumentation.
Patient-specific biomechanical model was used to computationally simulate seven hyperkyphotic instrumentation cases with three osteotomy strategies-1-level PSO, 3-level PO, or 6-level PO; forces within the instrumented spine were assessed and results were analyzed through rANOVA tests.
Corrections with multi-level PO were close to those with one-level PSO. In upright position, average implant forces were from 225 to 280 N and rod bending moments were around 10 Nm with no significant difference between the three strategies (p < 0.05). In simulations of 30° flexion, rod bending moments increased by 38, 2, and 8 %, implant forces increased by 28, 23 and 26 % for the 1-level PSO, 3-level PO, and 6-level PO, respectively. Correction per vertebral level was smaller than the maximum correction allowed by PO and PSO.
Multi-level PO allows similar kyphotic correction to 1-level PSO in spinal deformities with mixed indications for PO and PSO. Loads on the instrumentation constructs in PSO were higher than multi-level PO and higher in 6-level PO than 3-level PO. High loads were located more on the osteotomy sites. The rod shape should be adapted to the anticipated spine correction on the osteotomy sites.
对脊柱后凸畸形器械固定中 Ponte（PO）截骨术和椎弓根截骨术（PSO）进行生物力学分析。
使用患者特异性生物力学模型对七例严重脊柱后凸器械固定病例进行计算模拟，采用三种截骨策略——单节段 PSO、三节段 PO 或六节段 PO；评估器械固定脊柱内的力，并通过重复测量方差分析测试分析结果。
多节段 PO 的矫正效果与单节段 PSO 相近。在直立位时，三种策略的平均植入物受力为 225 至 280 N，棒材弯矩约为 10 Nm，差异无统计学意义（p < 0.05）。在 30°屈曲模拟中，单节段 PSO、三节段 PO 和六节段 PO 的棒材弯矩分别增加了 38%、2%和 8%，植入物受力分别增加了 28%、23%和 26%。每个椎体节段的矫正小于 PO 和 PSO 允许的最大矫正量。
在 PO 和 PSO 有混合适应证的脊柱畸形中，多节段 PO 可实现与单节段 PSO 相似的后凸矫正。PSO 中器械结构上的负荷高于多节段 PO，六节段 PO 高于三节段 PO。高负荷更多位于截骨部位。棒材形状应根据截骨部位预期的脊柱矫正进行调整。
