Tierney Ryan T, Maldjian Catherine, Mattacola Carl G, Straub Stephen J, Sitler Michael R
Temple University, Philadelphia, PA.
J Athl Train. 2002 Jun;37(2):190-193.
To compare 2 methods of determining cervical spinal stenosis (Torg ratio, space available for the cord [SAC]); determine which of the components of the Torg ratio and the SAC account for more of the variability in the measures; and present standardized SAC values for normal subjects using magnetic resonance imaging (MRI). DESIGN AND SETTING: The research design consisted of a posttest-only, comparison-group design. The independent variable was method of measurement (Torg ratio and SAC). The dependent variables were Torg ratio and SAC scores. SUBJECTS: Fourteen men (age = 24.4 +/- 2.5 years, height = 181.0 +/- 5.8 cm, weight = 90 +/- 13.5 kg) participated in this study. The C3 to C7 vertebrae were examined in each subject (n = 70). MEASUREMENTS: The Torg ratio was determined by dividing the sagittal spinal-canal diameter by the corresponding sagittal vertebral-body diameter. The SAC was determined by subtracting the sagittal spinal-cord diameter from the corresponding sagittal spinal-canal diameter. The Torg ratio and SAC were measured in millimeters. RESULTS: The SAC ranged from 2.5 to 10.4 mm and was greatest at C7 in 71% (10 of 14) of the subjects. The SAC was least at C3 or C5 in 71% (10 of 14) of the subjects. A Pearson product moment correlation revealed a significant relationship between the Torg ratio and SAC (r =.53, P <.01). Regression analyses revealed the vertebral body (r (2) =.58) accounted for more variability in the Torg ratio than the spinal canal (r (2) =.48). Also, the spinal canal (r (2) =.66) accounted for more variability in the SAC than the spinal cord (r (2) =.23). CONCLUSIONS: The SAC measure relies more on the spinal canal compared with the Torg ratio and, therefore, may be a more effective indicator of spinal stenosis. This is relevant clinically because neurologic injury related to stenosis is a function of the spinal canal and the spinal cord (not the vertebral body). Further research must be done, however, to validate the SAC measure.
比较两种确定颈椎管狭窄的方法（Torg比率、脊髓可用空间[SAC]）；确定Torg比率和SAC的各组成部分中哪一个在测量值的变异性中占比更大；并使用磁共振成像（MRI）给出正常受试者的标准化SAC值。
研究设计为仅后测、比较组设计。自变量为测量方法（Torg比率和SAC）。因变量为Torg比率和SAC分数。
14名男性（年龄 = 24.4 ± 2.5岁，身高 = 181.0 ± 5.8厘米，体重 = 90 ± 13.5千克）参与本研究。对每名受试者的C3至C7椎体进行检查（n = 70）。
Torg比率通过将矢状椎管直径除以相应的矢状椎体直径来确定。SAC通过从相应的矢状椎管直径中减去矢状脊髓直径来确定。Torg比率和SAC以毫米为单位进行测量。
SAC范围为2.5至10.4毫米，71%（14名中的10名）受试者在C7处最大。71%（14名中的10名）受试者在C3或C5处SAC最小。Pearson积差相关显示Torg比率与SAC之间存在显著关系（r = 0.53，P < 0.01）。回归分析显示椎体（r² = 0.58）在Torg比率中的变异性比椎管（r² = 0.48）更大。此外，椎管（r² = 0.66）在SAC中的变异性比脊髓（r² = 0.23）更大。
与Torg比率相比，SAC测量更多地依赖于椎管，因此可能是椎管狭窄更有效的指标。这在临床上具有相关性，因为与狭窄相关的神经损伤是椎管和脊髓（而非椎体）的函数。然而，必须进行进一步研究以验证SAC测量。
