Abstract：
OBJECTIVE: Previous work comparing ASD to a normative population demonstrated that a large proportion of lumbar lordosis is lost proximally (L1-L4). The current study expands on these findings by collectively investigating regional angles and spinal contours.
METHODS: 119 asymptomatic volunteers with full-body free-standing radiographs were used to identify age-and-PI models of each Vertebra Pelvic Angle (VPA) from L5 to T10. These formulas were then applied to a cohort of primary surgical ASD patients without coronal malalignment. Loss of lumbar lordosis (LL) was defined as the offset between age-and-PI normative value and pre-operative alignment. Spine shapes defined by VPAs were compared and analyzed using paired t-tests.
RESULTS: 362 ASD patients were identified (age = 64.4 ± 13, 57.1% females). Compared to their age-and-PI normative values, patients demonstrated a significant loss in LL of 17 ± 19° in the following distribution: 14.1% had \"No loss\" (mean = 0.1 ± 2.3), 22.9% with 10°-loss (mean = 9.9 ± 2.9), 22.1% with 20°-loss (mean = 20.0 ± 2.8), and 29.3% with 30°-loss (mean = 33.8 ± 6.0). \"No loss\" patients\' spine was slightly posterior to the normative shape from L4 to T10 (VPA difference of 2°), while superimposed on the normative one from S1 to L2 and became anterior at L1 in the \"10°-loss\" group. As LL loss increased, ASD and normative shapes offset extended caudally to L3 for the \"20°-loss\" group and L4 for the \"30°-loss\" group.
CONCLUSIONS: As LL loss increases, the difference between ASD and normative shapes first occurs proximally and then progresses incrementally caudally. Understanding spinal contour and LL loss location may be key to achieving sustainable correction by identifying optimal and personalized postoperative shapes.
METHODS: 119 asymptomatic volunteers with full-body free-standing radiographs were used to identify age-and-PI models of each Vertebra Pelvic Angle (VPA) from L5 to T10. These formulas were then applied to a cohort of primary surgical ASD patients without coronal malalignment. Loss of lumbar lordosis (LL) was defined as the offset between age-and-PI normative value and pre-operative alignment. Spine shapes defined by VPAs were compared and analyzed using paired t-tests.
RESULTS: 362 ASD patients were identified (age = 64.4 ± 13, 57.1% females). Compared to their age-and-PI normative values, patients demonstrated a significant loss in LL of 17 ± 19° in the following distribution: 14.1% had \"No loss\" (mean = 0.1 ± 2.3), 22.9% with 10°-loss (mean = 9.9 ± 2.9), 22.1% with 20°-loss (mean = 20.0 ± 2.8), and 29.3% with 30°-loss (mean = 33.8 ± 6.0). \"No loss\" patients\' spine was slightly posterior to the normative shape from L4 to T10 (VPA difference of 2°), while superimposed on the normative one from S1 to L2 and became anterior at L1 in the \"10°-loss\" group. As LL loss increased, ASD and normative shapes offset extended caudally to L3 for the \"20°-loss\" group and L4 for the \"30°-loss\" group.
CONCLUSIONS: As LL loss increases, the difference between ASD and normative shapes first occurs proximally and then progresses incrementally caudally. Understanding spinal contour and LL loss location may be key to achieving sustainable correction by identifying optimal and personalized postoperative shapes.
摘要：
目的：先前的工作将ASD与规范人群进行比较，表明大部分腰椎前凸在近端消失（L1-L4）。当前的研究通过共同调查区域角度和脊柱轮廓来扩展这些发现。
方法：使用119名无症状志愿者的全身自由站立X光片，以确定从L5到T10的每个椎骨骨盆角（VPA）的年龄和PI模型。然后将这些公式应用于一组没有冠状排列异常的原发性手术ASD患者。腰椎前凸（LL）的丧失定义为年龄和PI标准值与术前对齐之间的偏移。使用配对t检验比较和分析由VPA定义的脊柱形状。
结果：362名ASD患者（年龄=64.4±13，57.1％为女性）。与他们的年龄和PI标准值相比，患者在以下分布中表现出17±19°的LL显着损失：14.1%的患者“无损失”（平均值=0.1±2.3），22.9%，损失10°（平均值=9.9±2.9），22.1%，损失20°（平均值=20.0±2.8），和29.3%，30°损失(平均值=33.8±6.0)。从L4到T10，“无丢失”患者的脊柱稍微靠后规范形状（VPA相差2°），在“10°损失”组中，从S1到L2叠加在规范的水平上，并在L1处变为前。随着LL损失的增加，对于“20°损失”组，ASD和规范形状向尾部延伸至L3，对于“30°损失”组，向尾部延伸至L4。
结论：随着LL损失的增加，ASD和规范形状之间的差异首先发生在近端，然后逐渐向尾。了解脊柱轮廓和LL丢失位置可能是通过识别最佳和个性化的术后形状来实现可持续矫正的关键。
方法：使用119名无症状志愿者的全身自由站立X光片，以确定从L5到T10的每个椎骨骨盆角（VPA）的年龄和PI模型。然后将这些公式应用于一组没有冠状排列异常的原发性手术ASD患者。腰椎前凸（LL）的丧失定义为年龄和PI标准值与术前对齐之间的偏移。使用配对t检验比较和分析由VPA定义的脊柱形状。
结果：362名ASD患者（年龄=64.4±13，57.1％为女性）。与他们的年龄和PI标准值相比，患者在以下分布中表现出17±19°的LL显着损失：14.1%的患者“无损失”（平均值=0.1±2.3），22.9%，损失10°（平均值=9.9±2.9），22.1%，损失20°（平均值=20.0±2.8），和29.3%，30°损失(平均值=33.8±6.0)。从L4到T10，“无丢失”患者的脊柱稍微靠后规范形状（VPA相差2°），在“10°损失”组中，从S1到L2叠加在规范的水平上，并在L1处变为前。随着LL损失的增加，对于“20°损失”组，ASD和规范形状向尾部延伸至L3，对于“30°损失”组，向尾部延伸至L4。
结论：随着LL损失的增加，ASD和规范形状之间的差异首先发生在近端，然后逐渐向尾。了解脊柱轮廓和LL丢失位置可能是通过识别最佳和个性化的术后形状来实现可持续矫正的关键。
