The Torg-Pavlov ratio in cervical spondylotic myelopathy - A comparative study between patients with cervical spondylotic myelopathy and nonspondylotic, nonmyelopathic population

Study Design. A radiologic study to compare the Torg-Pavlov ratios between patients with cervical spondylotic myelopathy and a nonspondylotic, nonmyel opathic population. Objectives. To determine and compare the Torg-Pavlov ratios between the two groups of patients. Summary of Background Data. Patients with congenital cervical spinal canal stenosis are more likely to develop cervical spondylotic myelopathy. The To rg-Pavlov ratio eliminates errors related to magnification, a problem with determination of spinal canal stenosis from direct measurements of plain ce rvical spine radiographs. There has only been one other study that directly compares the Torg-Pavlov ratio between patients with cervical spondylotic myelopathy and a normal control population. Methods. The preoperative plain lateral cervical spine radiographs of 28 pa tients with cervical spondylotic myelopathy requiring surgical decompressio n were compared with radiographs of 88 nonspondylotic, nonmyelopathic patie nts. The Torg-Pavlov ratio was computed for each level from C3 to C7. Results. The study showed that the Torg-Pavlov ratio is significantly small er (P < 0.001) in myelopathic patients (mean 0.72 +/- 0.08) compared with t he control patients (mean 0.95 +/- 0.14). This was so when individual level s and the mean values were compared. Age was also found to be a significant factor (P = 0.002), although lesser in magnitude when compared with the To rg-Pavlov ratio (P = 0.0001). Conclusions. The Torg-Pavlov ratio is significantly lower in patients with cervical spondylotic myelopathy compared with a nonspondylotic, nonmyelopat hic population. It could possibly be used to predict the likelihood of deve loping cervical spondylotic myelopathy.