Chen I H, Liao K K, Shen W Y
Department of Neurosurgery, Taipei Municipal Chung-Shiao Hospital, Taiwan, R.O.C.
Zhonghua Yi Xue Za Zhi (Taipei). 1994 Aug;54(2):105-10.
Cervical canal encroachment can be properly assessed from lateral cervical radiographs either by defining its magnification rate or by a ratio-method. Data of the latter obtained from Chinese males with cervical myelopathy were compared with the data of general population in different age groups.
A total of 200 Chinese males were included in this study. Half of them had undergone decompressive procedures for cervical myelopathy, while the remaining 100 cases were volunteers. Sagittal diameters of cervical canal and vertebra were measured from C3 to C6 on lateral cervical radiographs, while ratios (Torg-Pavlov's ratios) of the two reflected the extent of sagittal canal encroachment. Cut-off values and discriminant rates of these parameters in different age groups were obtained by discriminant analysis. The tube-to-film distance was set as 40 inches.
In myelopathic group (age < 55 y/o), Torg-Pavlov's ratios, as expressed by mean +/- standard deviation, were 0.77 +/- 0.12 for C3, 0.75 +/- 0.14 for C4, 0.80 +/- 0.14 for C5, and 0.81 +/- 0.15 for C6. In control group (age < 55 y/o) the ratios were 0.94 +/- 0.12, 0.95 +/- 0.13, 0.97 +/- 0.13, and 0.97 +/- 0.13 respectively. In myelopathic group (age > or = 55 y/o), the ratios were 0.76 +/- 0.09, 0.71 +/- 0.10, 0.73 +/- 0.11, and 0.76 +/- 0.11; while in control group (age > or = 55 y/o), the ratios were 0.93 +/- 0.10, 0.89 +/- 0.09, 0.88 +/- 0.11, and 0.91 +/- 0.12 respectively. The cutoff values and their discriminant rates are also presented.
The differences of canal sagittal diameter as well as Torg-Pavlov ratio between myelopathic and control group of Chinese males in individual age group were statistically significant. It is concluded that congenitally narrow cervical canal is a major predisposing factor to cervical spondylotic myelopathy.
颈椎管狭窄可通过颈椎侧位X线片确定其放大率或采用比值法进行准确评估。将中国男性脊髓型颈椎病患者采用比值法获得的数据与不同年龄组的普通人群数据进行比较。
本研究共纳入200名中国男性。其中一半因脊髓型颈椎病接受了减压手术，其余100例为志愿者。在颈椎侧位X线片上测量C3至C6节段的颈椎管矢状径和椎体矢状径，两者的比值（Torg-Pavlov比值）反映矢状椎管狭窄程度。通过判别分析得出不同年龄组这些参数的临界值和判别率。管片距离设定为40英寸。
在脊髓型颈椎病组（年龄<55岁），C3、C4、C5、C6节段的Torg-Pavlov比值，以均值±标准差表示，分别为0.77±0.12、0.75±0.14、0.80±0.14和0.81±0.15。对照组（年龄<55岁）的比值分别为0.94±0.12、0.95±0.13、0.97±0.13和0.97±0.13。在脊髓型颈椎病组（年龄≥55岁），比值分别为0.76±0.09、0.71±0.10、0.73±0.11和0.76±0.11；而对照组（年龄≥55岁）的比值分别为0.93±0.10、0.89±0.09、0.88±0.11和0.91±0.12。还列出了临界值及其判别率。
中国男性脊髓型颈椎病组与对照组在各年龄组的椎管矢状径以及Torg-Pavlov比值差异具有统计学意义。得出先天性颈椎管狭窄是颈椎病性脊髓病的主要易感因素的结论。
