Chen I H, Vasavada A, Panjabi M M
Division of Neurosurgery, Veterans General Hospital, Taipei, Taiwan, Republic of China.
J Spinal Disord. 1994 Apr;7(2):93-101. doi: 10.1097/00002517-199407020-00001.
Spondylotic myelopathy is a result of decreased spinal canal space due to degeneration. The space also may change with physiological movements. The knowledge of the normal physiological changes is necessary for a better understanding of the clinical symptoms. Using a novel technique, we measured the changes in disk bulge, ligamentum flavum bulge, and anteroposterior canal diameter in response to tension-compression forces (up to 40 N each) and combined loading: 2 Nm of flexion or extension moment combined with 20 N compression force in five human cadaveric lower cervical spine specimens (C4-C7). From tension to compression, the average disk bulge changed 1.13 mm or 10.1% of the original canal diameter. The ligamentum flavum bulge changed 0.73 mm or 6.5% of the canal diameter. From flexion to extension the average disk bulb changed 1.16 mm or 10.8% of the canal diameter, whereas the ligamentum flavum bulge changed 2.68 mm or 24.3% of the canal diameter. Most of the changes in the bulges occurred with a small load application around the neutral position of the spine. The results of this study demonstrate that ligamentum flavum bulge can contribute significantly to canal encroachment in extension and that a flexed posture increases the sagittal diameter of the spinal canal.
脊髓型颈椎病是由于退变导致椎管空间减小的结果。该空间也可能随生理运动而变化。了解正常的生理变化对于更好地理解临床症状是必要的。我们采用一种新技术，在五具人类尸体下颈椎标本（C4 - C7）中，测量了椎间盘膨出、黄韧带膨出以及椎管前后径在张力 - 压缩力（各高达40 N）和联合加载作用下的变化：2 Nm的屈曲或伸展力矩与20 N压缩力联合作用。从张力到压缩，椎间盘平均膨出变化了1.13 mm，占原始椎管直径的10.1%。黄韧带膨出变化了0.73 mm，占椎管直径的6.5%。从屈曲到伸展，椎间盘平均膨出变化了1.16 mm，占椎管直径的10.8%，而黄韧带膨出变化了2.68 mm，占椎管直径的24.3%。大多数膨出变化发生在脊柱中立位附近施加小负荷时。本研究结果表明，黄韧带膨出在伸展时可显著导致椎管侵占，并且屈曲姿势会增加椎管矢状径。
