Cervical motion segment percent contributions to flexion-extension during continuous functional movement in control subjects and arthrodesis patients.
Cervical motion segment percent contributions to flexion-extension during continuous functional movement in control subjects and arthrodesis patients.
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DOI：
10.1097/brs.0b013e318289378d
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发表时间：
2013-04-20
期刊：
影响因子：
3
通讯作者：
Kang JD
中科院分区：
文献类型：
--
作者：
Anderst WJ;Donaldson WF 3rd;Lee JY;Kang JD
病例对照精确量化并比较无症状受试者与单节段前路关节融合术患者在连续、功能性屈曲-伸展过程中椎间节段对颈椎屈曲-伸展的贡献。传统上使用在完全屈曲和完全伸展时收集的单个图像来确定节段对颈椎屈曲-伸展的贡献。这些计算忽略了中程运动，并假设在整个屈曲-伸展运动范围（ROM）内对运动的贡献百分比保持不变。6例单节段（C5/C6）前路关节融合术患者和18例无症状对照受试者进行屈曲-伸展，同时以每秒30张图像采集双平面X线片。先前确认的跟踪过程确定了连续屈曲-伸展期间的三维椎体位置，精度为亚毫米。节段百分比贡献C2/C7屈伸的混合效应模型被开发，以确定在每个运动节段内，运动节段之间，以及对照组和关节融合术患者之间的百分比贡献的差异在整个ROM。C2/C3，C3/C4和C4/C5运动节段的最大贡献在中等范围的运动。相反，C5/C6和C6/C7运动节段，在ROM的开始和结束附近做出了最大贡献。关节固定术患者的C4/C5运动节段的贡献在整个活动范围内显着增加，从总屈伸ROM的30%增加到95%（平均增加5.1%）和关节融合术患者的C6/C7运动节段的贡献在整个屈曲-伸展ROM中显著增加（平均贡献率增加8.9%）。颈椎运动节段对屈伸运动的贡献在屈伸运动过程中变化显著。相对于对照组，在整个活动范围内，对活动的贡献百分比变化最大的发生在C6/C7运动节段，这表明在C5/C6关节融合术后，临床观察到C6/C7而不是C4/C5相邻节段退变发生率增加的潜在机械机制。
Case-control. To precisely quantify and compare intervertebral segmental contributions to cervical spine flexion-extension during continuous, functional flexion-extension in asymptomatic subjects to single-level anterior arthrodesis patients. Segmental contributions to cervical flexion-extension have traditionally been determined using single images collected at full flexion and full extension. These calculations neglect mid-range motion, and assume percentage contributions to motion remain constant throughout the entire flexion-extension range of motion (ROM). 6 single-level (C5/C6) anterior arthrodesis patients and 18 asymptomatic control subjects performed flexion-extension while biplane radiographs were collected at 30 images per second. A previously validated tracking process determined three-dimensional vertebral position with sub-millimeter accuracy during continuous flexion-extension. Mixed-effects models of segmental percentage contribution to C2/C7 flexion-extension were developed to identify differences in percentage contribution within each motion segment, among motion segments, and between control and arthrodesis patients over the full ROM. The C2/C3, C3/C4 and C4/C5 motion segments made their maximum contributions during the mid-range of motion. The C5/C6 and C6/C7 motion segments, in contrast, made their maximum contributions near the start and end of the ROM. Arthrodesis patients’ contribution from the C4/C5 motion segment increased significantly over the range of motion from 30% to 95% of the total flexion-extension ROM (average increased contribution of 5.1%) and arthrodesis patients’ contribution from the C6/C7 motion segment increased significantly over the entire flexion-extension ROM (average increased percentage contribution of 8.9%) in comparison to controls. Cervical motion segment contributions to flexion-extension change significantly during the flexion-extension motion. The largest change in percentage contribution to motion, relative to controls, occurs at the C6/C7 motion segment, over the entire range of motion, suggesting a potential mechanical mechanism for the clinical observation of increased incidence of adjacent segment degeneration at C6/C7 rather than at C4/C5 following C5/C6 arthrodesis.