Lee Dong-Ho, Ha Jung-Ki, Chung Jae-Hak, Hwang Chang Ju, Lee Choon Sung, Cho Jae Hwan
Department of Orthopedic Surgery, Asan Medical Center, University of Ulsan College of Medicine, 388-1, PungNap-2-dong, SongPa-gu, Seoul, Korea.
Eur Spine J. 2016 Jul;25(7):2286-93. doi: 10.1007/s00586-016-4392-9. Epub 2016 Jan 25.
Recent studies suggest that cervical lordosis is influenced by thoracic kyphosis and that T1 slope is a key factor determining cervical sagittal alignment. However, no previous study has investigated the influence of cervical kyphosis correction on the remaining spinopelvic balance. The purpose of this study is to assess the effect of surgical correction of cervical kyphosis on thoraco-lumbo-pelvic alignment.
Fifty-five patients who underwent ≥2 level cervical fusions for cervical radiculopathy or myelopathy were included. All patients had regional or global cervical kyphosis, which was surgically corrected into lordosis. Radiographic measurements were made using whole spine standing lateral radigraphs pre- and postoperatively to analyze various sagittal parameters. The visual analogue scale (VAS) for neck pain and the neck disability index (NDI) were calculated. The paired t test was used to compare pre- and post-operative radiographic measures and functional scores. Correlations between changes in cervical sagittal parameters and those of other sagittal parameters were analyzed by Pearson's correlation method.
Preoperative kyphosis (11.4° ± 8.3°) was corrected into lordosis (-9.3° ± 8.1°). The average fusion levels were 3.3 ± 1.0. With increasing C2-C7 lordosis after surgery (from -3.4° ± 10.0° to -15° ± 7.9°), C0-C2 lordosis decreased significantly (from -34.6° ± 8.2° to -27.7° ± 8.0°) (P < 0.001). Thoracic kyphosis (from 24.8 ± 13.9° to 33.5 ± 11.9°) and T1 slope (from 12.8° ± 7.9° to 20.4° ± 5.2°) significantly increased after surgery (P < 0.001). However, other parameters did not significantly change (P > 0.05). Neck pain VAS and NDI scores (31.8 ± 16.2) significantly improved (P < 0.001). The degree of increasing C2-C7 lordosis by surgical correction was negatively correlated with changes in both thoracic kyphosis and T1 slope (P < 0.01).
Surgical correction of cervical kyphosis affects T1 slope and thoracic kyphosis, but not lumbo-pelvic alignment. These results indicate that the compensatory mechanisms to minimize positive sagittal malalignment of the head may occur mainly in the thoracic, and not in the lumbosacral spine.
近期研究表明颈椎前凸受胸椎后凸影响，且T1斜率是决定颈椎矢状位对线的关键因素。然而，既往尚无研究探讨颈椎后凸矫正对其余脊柱骨盆平衡的影响。本研究旨在评估颈椎后凸手术矫正对胸腰段骨盆对线的影响。
纳入55例因神经根型颈椎病或脊髓型颈椎病接受≥2节段颈椎融合术的患者。所有患者均存在节段性或整体性颈椎后凸，通过手术矫正为前凸。术前和术后使用全脊柱站立位侧位X线片进行影像学测量，以分析各种矢状位参数。计算颈部疼痛视觉模拟量表（VAS）和颈部功能障碍指数（NDI）。采用配对t检验比较术前和术后的影像学测量结果及功能评分。采用Pearson相关方法分析颈椎矢状位参数变化与其他矢状位参数变化之间的相关性。
术前的后凸（11.4°±8.3°）矫正为前凸（-9.3°±8.1°）。平均融合节段为3.3±1.0。随着术后C2-C7前凸增加（从-3.4°±10.0°至-15°±7.9°），C0-C2前凸显著降低（从-34.6°±8.2°至-27.7°±8.0°）（P<0.001）。术后胸椎后凸（从24.8±13.9°至33.5±11.9°）和T1斜率（从12.8°±7.9°至20.4°±5.2°）显著增加（P<0.001）。然而，其他参数无显著变化（P>0.05）。颈部疼痛VAS和NDI评分（31.8±16.2）显著改善（P<0.001）。手术矫正增加C2-C7前凸的程度与胸椎后凸和T1斜率的变化均呈负相关（P<0.01）。
颈椎后凸的手术矫正影响T1斜率和胸椎后凸，但不影响腰骶部对线。这些结果表明，使头部矢状位畸形最小化的代偿机制可能主要发生在胸椎，而非腰骶椎。
