Abstract：
BACKGROUND: Previous research has identified a specific subtype known as failure of pelvic compensation (FPC) in patients with adult spinal deformity (ASD). However, the criteria for assessing FPC remain inconsistent, and its impacts on spinal sagittal alignment and health-related quality-of-life (HRQoL) scores remain unclear.
OBJECTIVE: To propose a novel criterion for identifying FPC based on variations in spinopelvic alignment during the transition from the supine to upright position and to evaluate the effects of FPC on patients\' spinal sagittal alignment and HRQoL scores.
METHODS: Retrospective cross-sectional study.
METHODS: Patients with ASD from a monocenter database.
METHODS: Radiographic measures, including thoracic kyphosis (TK), lumbar lordosis (LL), sacral slope (SS), pelvic tilt, pelvic incidence (PI), and sagittal vertical axis (SVA), were measured on lateral whole-spine radiographs. LL and SS were also measured on reconstructed lumbar computed tomography images in the sagittal view taken in the supine position. The relative functional cross-sectional area (rFCSA) of paraspinal muscles was evaluated via lumbar magnetic resonance imaging. HRQoL measures, encompassing visual analog scale for back pain (VAS-BP), Oswestry Disability Index (ODI), and Scoliosis Research Society-22R (SRS-22R), were collected.
METHODS: A total of 154 patients were enrolled. Based on the calculated minimum detectable change of SS, FPC was defined as the change in SS of less than 3.4° between supine and upright positions. Patients were divided into 3 groups: sagittal balance with pelvic compensation (SI-PC), sagittal imbalance with pelvic compensation (SI-PC), and sagittal imbalance with failure of pelvic compensation (SI-FPC). Radiographic parameters and HRQoL scores were compared among the groups.
RESULTS: Thirty-six patients were categorized into the SB-PC group, 87 into the SI-PC group, and 31 into the SI-FPC group. Patients with low PI and small paraspinal muscles rFCSA were more prone to experiencing FPC accompanied by severe sagittal imbalance. The SI-FPC group exhibited less TK and a larger SS than the SI-PC group exhibited and had a similar SVA as that of the SI-PC group. Additionally, they displayed worse VAS-BP, ODI, SRS-function, and SRS-22 total scores than the SB-PC group displayed.
CONCLUSIONS: In patients with ASD, an inherently low pelvic compensatory reserve and a high fatty infiltration in paraspinal muscles are pivotal factors contributing to FPC. Compared with SI-PC patients, SI-FPC patients demonstrate a thoracic-dominant compensatory pattern for sagittal malalignment. In addition, these patients experienced more severe pain and functional decline than the SB-PC patients experienced.
OBJECTIVE: To propose a novel criterion for identifying FPC based on variations in spinopelvic alignment during the transition from the supine to upright position and to evaluate the effects of FPC on patients\' spinal sagittal alignment and HRQoL scores.
METHODS: Retrospective cross-sectional study.
METHODS: Patients with ASD from a monocenter database.
METHODS: Radiographic measures, including thoracic kyphosis (TK), lumbar lordosis (LL), sacral slope (SS), pelvic tilt, pelvic incidence (PI), and sagittal vertical axis (SVA), were measured on lateral whole-spine radiographs. LL and SS were also measured on reconstructed lumbar computed tomography images in the sagittal view taken in the supine position. The relative functional cross-sectional area (rFCSA) of paraspinal muscles was evaluated via lumbar magnetic resonance imaging. HRQoL measures, encompassing visual analog scale for back pain (VAS-BP), Oswestry Disability Index (ODI), and Scoliosis Research Society-22R (SRS-22R), were collected.
METHODS: A total of 154 patients were enrolled. Based on the calculated minimum detectable change of SS, FPC was defined as the change in SS of less than 3.4° between supine and upright positions. Patients were divided into 3 groups: sagittal balance with pelvic compensation (SI-PC), sagittal imbalance with pelvic compensation (SI-PC), and sagittal imbalance with failure of pelvic compensation (SI-FPC). Radiographic parameters and HRQoL scores were compared among the groups.
RESULTS: Thirty-six patients were categorized into the SB-PC group, 87 into the SI-PC group, and 31 into the SI-FPC group. Patients with low PI and small paraspinal muscles rFCSA were more prone to experiencing FPC accompanied by severe sagittal imbalance. The SI-FPC group exhibited less TK and a larger SS than the SI-PC group exhibited and had a similar SVA as that of the SI-PC group. Additionally, they displayed worse VAS-BP, ODI, SRS-function, and SRS-22 total scores than the SB-PC group displayed.
CONCLUSIONS: In patients with ASD, an inherently low pelvic compensatory reserve and a high fatty infiltration in paraspinal muscles are pivotal factors contributing to FPC. Compared with SI-PC patients, SI-FPC patients demonstrate a thoracic-dominant compensatory pattern for sagittal malalignment. In addition, these patients experienced more severe pain and functional decline than the SB-PC patients experienced.
摘要：
背景：先前的研究已经确定了成人脊柱畸形（ASD）患者的一种特定亚型，称为骨盆代偿失败（FPC）。然而,评估FPC的标准仍然不一致，其对脊柱矢状面排列和健康相关生活质量(HRQoL)评分的影响尚不清楚.
目的：根据仰卧位到直立位的脊柱骨盆排列变化，提出一种新的识别FPC的标准，并评估FPC对患者脊柱矢状位和HRQoL评分的影响。
方法：回顾性横断面研究。
方法：来自单中心数据库的ASD患者。
方法：射线照相措施，包括胸椎后凸(TK),腰椎前凸(LL),骶骨斜坡(SS),骨盆倾斜,骨盆发病率（PI），和矢状垂直轴(SVA)，在外侧全脊柱X光片上测量。LL和SS还在仰卧位的矢状视图中在重建的腰椎计算机断层扫描图像上进行了测量。通过腰椎磁共振成像评估椎旁肌的相对功能横截面积（rFCSA）。HRQoL措施，包括背痛视觉模拟量表（VAS-BP），Oswestry残疾指数（ODI），和脊柱侧弯研究学会-22R(SRS-22R)，被收集。
方法：共纳入154例患者。根据计算出的SS的最小可检测变化，FPC定义为仰卧位和直立位之间小于3.4°的SS变化。患者分为三组：矢状面平衡与骨盆代偿（SI-PC），矢状不平衡与骨盆补偿（SI-PC），矢状失衡伴骨盆代偿失败(SI-FPC)。比较各组的影像学参数和HRQoL评分。
结果：36例患者被归类为SB-PC组，87进入SI-PC组，和31进入SI-FPC组。低PI和椎旁肌rFCSA小的患者更容易出现FPC并伴有严重的矢状失衡。SI-FPC组表现出比SI-PC组少的TK和大的SS,并且具有与SI-PC组相似的SVA。此外,他们表现出更差的VAS-BP，ODI,SRS功能,和SRS-22总分比显示的SB-PC组。
结论：在ASD患者中，固有的低骨盆代偿储备和椎旁肌的高脂肪浸润是导致FPC的关键因素。与SI-PC患者相比，SI-FPC患者表现出矢状错位的胸部优势代偿模式。此外,与SB-PC患者相比,这些患者经历了更严重的疼痛和功能减退.
目的：根据仰卧位到直立位的脊柱骨盆排列变化，提出一种新的识别FPC的标准，并评估FPC对患者脊柱矢状位和HRQoL评分的影响。
方法：回顾性横断面研究。
方法：来自单中心数据库的ASD患者。
方法：射线照相措施，包括胸椎后凸(TK),腰椎前凸(LL),骶骨斜坡(SS),骨盆倾斜,骨盆发病率（PI），和矢状垂直轴(SVA)，在外侧全脊柱X光片上测量。LL和SS还在仰卧位的矢状视图中在重建的腰椎计算机断层扫描图像上进行了测量。通过腰椎磁共振成像评估椎旁肌的相对功能横截面积（rFCSA）。HRQoL措施，包括背痛视觉模拟量表（VAS-BP），Oswestry残疾指数（ODI），和脊柱侧弯研究学会-22R(SRS-22R)，被收集。
方法：共纳入154例患者。根据计算出的SS的最小可检测变化，FPC定义为仰卧位和直立位之间小于3.4°的SS变化。患者分为三组：矢状面平衡与骨盆代偿（SI-PC），矢状不平衡与骨盆补偿（SI-PC），矢状失衡伴骨盆代偿失败(SI-FPC)。比较各组的影像学参数和HRQoL评分。
结果：36例患者被归类为SB-PC组，87进入SI-PC组，和31进入SI-FPC组。低PI和椎旁肌rFCSA小的患者更容易出现FPC并伴有严重的矢状失衡。SI-FPC组表现出比SI-PC组少的TK和大的SS,并且具有与SI-PC组相似的SVA。此外,他们表现出更差的VAS-BP，ODI,SRS功能,和SRS-22总分比显示的SB-PC组。
结论：在ASD患者中，固有的低骨盆代偿储备和椎旁肌的高脂肪浸润是导致FPC的关键因素。与SI-PC患者相比，SI-FPC患者表现出矢状错位的胸部优势代偿模式。此外,与SB-PC患者相比,这些患者经历了更严重的疼痛和功能减退.
