Abstract：
Sagittal malalignment is a risk factor for mechanical complications after surgery for adult spinal deformity (ASD). Spinal loads, modulated by sagittal alignment, may explain this relationship. The aims of this study were to investigate the relationships between: (1) postoperative changes in loads at the proximal segment and realignment, and (2) absolute postoperative loads and postoperative alignment measures.
A previously validated musculoskeletal model of the whole spine was applied to study a clinical sample of 205 patients with ASD. Based on clinical and radiographic data, pre-and postoperative patient-specific alignments were simulated to predict loads at the proximal segment adjacent to the spinal fusion.
Weak-to-moderate associations were found between pre-to-postop changes in lumbar lordosis, LL (r = - 0.23, r = - 0.43; p < 0.001), global tilt, GT (r = 0.26, r = 0.38; p < 0.001) and the Global Alignment and Proportion score, GAP (r = 0.26, r = 0.37; p < 0.001), and changes in compressive and shear forces at the proximal segment. GAP score parameters, thoracic kyphosis measurements and the slope of upper instrumented vertebra were associated with changes in shear. In patients with T10-pelvis fusion, moderate-to-strong associations were found between postoperative sagittal alignment measures and compressive and shear loads, with GT showing the strongest correlations (r = 0.75, r = 0.73, p < 0.001).
Spinal loads were estimated for patient-specific full spinal alignment profiles in a large cohort of patients with ASD pre-and postoperatively. Loads on the proximal segments were greater in association with sagittal malalignment and malorientation of proximal vertebra. Future work should explore whether they provide a causative mechanism explaining the associated risk of proximal junction complications.
A previously validated musculoskeletal model of the whole spine was applied to study a clinical sample of 205 patients with ASD. Based on clinical and radiographic data, pre-and postoperative patient-specific alignments were simulated to predict loads at the proximal segment adjacent to the spinal fusion.
Weak-to-moderate associations were found between pre-to-postop changes in lumbar lordosis, LL (r = - 0.23, r = - 0.43; p < 0.001), global tilt, GT (r = 0.26, r = 0.38; p < 0.001) and the Global Alignment and Proportion score, GAP (r = 0.26, r = 0.37; p < 0.001), and changes in compressive and shear forces at the proximal segment. GAP score parameters, thoracic kyphosis measurements and the slope of upper instrumented vertebra were associated with changes in shear. In patients with T10-pelvis fusion, moderate-to-strong associations were found between postoperative sagittal alignment measures and compressive and shear loads, with GT showing the strongest correlations (r = 0.75, r = 0.73, p < 0.001).
Spinal loads were estimated for patient-specific full spinal alignment profiles in a large cohort of patients with ASD pre-and postoperatively. Loads on the proximal segments were greater in association with sagittal malalignment and malorientation of proximal vertebra. Future work should explore whether they provide a causative mechanism explaining the associated risk of proximal junction complications.
摘要：
目的：矢状位错位是成人脊柱畸形（ASD）手术后机械并发症的危险因素。脊髓负荷,通过矢状对齐调制，可以解释这种关系。这项研究的目的是调查之间的关系：（1）近端段负荷的术后变化和重新对齐，(2)绝对术后负荷和术后对位措施。
方法：应用先前验证的整个脊柱的肌肉骨骼模型来研究205例ASD患者的临床样本。根据临床和影像学资料,我们模拟了患者术前和术后患者特异性对位,以预测脊柱融合术附近近端节段的负荷.
结果：在腰椎前凸的pre-to-posstop变化之间发现了轻度到中度的关联，LL（r=-0.23，r=-0.43；p<0.001），全局倾斜，GT(r=0.26，r=0.38；p<0.001)和全局对齐和比例评分，GAP（r=0.26，r=0.37；p<0.001），以及近端段的压缩力和剪切力的变化。GAP评分参数,胸椎后凸的测量值和上器械椎骨的斜率与剪切力的变化有关。在T10骨盆融合的患者中，发现术后矢状面对齐措施与压缩和剪切载荷之间存在中度到强烈的关联，GT表现出最强的相关性(r=0.75，r=0.73，p<0.001)。
结论：在大量ASD患者术前和术后，对患者特定的全脊柱排列曲线估计了脊柱负荷。与矢状错位和近端椎骨的定向错误相关，近端节段上的载荷更大。未来的工作应该探索它们是否提供了解释近端交界处并发症相关风险的致病机制。
方法：应用先前验证的整个脊柱的肌肉骨骼模型来研究205例ASD患者的临床样本。根据临床和影像学资料,我们模拟了患者术前和术后患者特异性对位,以预测脊柱融合术附近近端节段的负荷.
结果：在腰椎前凸的pre-to-posstop变化之间发现了轻度到中度的关联，LL（r=-0.23，r=-0.43；p<0.001），全局倾斜，GT(r=0.26，r=0.38；p<0.001)和全局对齐和比例评分，GAP（r=0.26，r=0.37；p<0.001），以及近端段的压缩力和剪切力的变化。GAP评分参数,胸椎后凸的测量值和上器械椎骨的斜率与剪切力的变化有关。在T10骨盆融合的患者中，发现术后矢状面对齐措施与压缩和剪切载荷之间存在中度到强烈的关联，GT表现出最强的相关性(r=0.75，r=0.73，p<0.001)。
结论：在大量ASD患者术前和术后，对患者特定的全脊柱排列曲线估计了脊柱负荷。与矢状错位和近端椎骨的定向错误相关，近端节段上的载荷更大。未来的工作应该探索它们是否提供了解释近端交界处并发症相关风险的致病机制。
