Standing Lateral Radiographic Positioning Does Not Represent Customary Standing Balance
Standing Lateral Radiographic Positioning Does Not Represent Customary Standing Balance
复制标题
站立侧位放射线定位并不代表习惯的站立平衡
DOI：
10.1097/01.brs.0000067271.00258.51
复制
发表时间：
2003
期刊：
影响因子：
3
通讯作者：
P. Newton
中科院分区：
文献类型：
--
作者：
M. Marks;Christian F Stanford;A. Mahar;P. Newton
研究设计。对现有矢状位脊柱平衡X线测量方法准确性的正常队列评估。目标。目的：检查在获得胸腰椎侧位X线片时，在各种常用站立姿势下测量矢状面垂直轴的有效性和可靠性。背景数据摘要。矢状面垂直轴是一种被广泛接受的脊柱整体矢状面排列的X线测量方法。然而，正常受试者在功能体位时并未测量到矢状面垂直轴，因为在拍摄脊柱侧位X光片时，手臂必须抬起。这项研究的目的是量化重复功能位置和X线位置之间的矢状轴测量的差异，以确定在X线测量矢状轴的潜在误差的大小。方法：研究方法。15名健康女性青少年身上贴着反光标记，覆盖在C7和S1的棘突上。在同步采集侧位X线片期间，通过运动捕捉系统记录标记位置。使用标记数据计算的矢状轴与通过使用人体测量校正的X线片获得的矢状轴测量相匹配，以将辐射限制在一次曝光中。检查了四种不同肩、膝屈曲和地面行走的站立姿势。用重复测量的方差分析比较每个站位和步态的平均矢状轴。房内和房间矢状轴测量的可重复性也被确定。结果。功能位(松弛站立：0.9±2.0 cm，整个步态：4.5±2.0 cm)的矢状位垂直轴为正值(位于S1前方C7)，而肩部屈曲导致负矢状位垂直轴(-4.6±3.2)和骨盆后方旋转。膝关节屈曲可使矢状轴相对前移。在放松站立和单独屈肩站立的试验间和心房内可靠性方面没有观察到差异。在涉及膝关节屈曲的重复试验中观察到变异性增加。结论。从常用的站立姿势(肩部屈曲)对X线片上的矢状轴进行测量，得到的矢状轴比在功能体位时观察到的矢状轴后移至少3到4厘米。受试者重新定位导致在矢状面垂直轴上至少有0.8厘米的试间变异，而受试者保持每个站立姿势的变化对总体测量误差的贡献很小。在分析的体位中，肩部屈曲(45°)是侧位X线片的最佳体位，因为对矢状面垂直轴测量的重复性影响最小。然而，所有的摄影姿势都没有重现受试者功能性站立姿势的脊柱平衡。
Study Design. Normal cohort evaluation of the accuracy of existing methods for radiographic measurement of sagittal spinal balance. Objectives. To examine the validity and reliability of sagittal vertical axis measurements during a variety of standing positions commonly used while obtaining lateral thoracolumbar spine radiographs. Summary of the Background Data. The sagittal vertical axis is a widely accepted radiographic measurement of global sagittal alignment of the spine. However, the sagittal vertical axis has not been measured in normal subjects while in functional positions because the arms must be elevated during acquisition of a lateral spinal radiograph. The purpose of this study was to quantify differences in sagittal vertical axis measurements between repeated functional positions and radiographic positions to identify the magnitude of the potential error in measuring the sagittal vertical axis radiographically. Methods. Reflective markers were attached to 15 healthy female adolescents, overlying the spinous processes of C7 and S1. Marker positions were recorded by a motion capture system during simultaneous acquisition of a lateral radiograph. Sagittal vertical axis calculation, using marker data, was matched to sagittal vertical axis measurement obtained by radiograph using anthropometric corrections to limit radiation to a single exposure. Four standing positions with varying shoulder and knee flexion as well as overground walking were examined. The mean sagittal vertical axis for each standing position and during gait was compared using a repeated measures analysis of variance. Intratrial and intertrial repeatability of sagittal vertical axis measurements was also determined. Results. The sagittal vertical axis was positive (C7 anterior to S1) for the functional positions (relaxed standing: 0.9 ± 2.0 cm, and throughout gait: 4.5 ± 2.0 cm), whereas shoulder flexion resulted in a negative sagittal vertical axis (-4.6 ± 3.2) and posterior rotation of the pelvis. Adding knee flexion resulted in a slight relative shift in the sagittal vertical axis anteriorly. No differences were observed in intertrial and intratrial reliability for relaxed standing and standing with shoulder flexion alone. Increased variability was observed between repeated trials involving knee flexion. Conclusions. Measurement of the sagittal vertical axis on radiographs from commonly utilized standing positions (shoulders flexed) results in an sagittal vertical axis that is at least 3 to 4 cm more posterior than a sagittal vertical axis observed during a functional position. Subject repositioning resulted in an intertrial variability of at least 0.8 cm in sagittal vertical axis, while variation as the subject held each standing posture had little contribution to overall error of measurement. Of the analyzed positions, shoulder flexion (45°) alone was the best position for a lateral radiograph due to minimal compromise to repeatability of sagittal vertical axis measurement. However, none of the radiographic positions reproduced the spinal balance of the subject’s functional standing posture.