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, nonmyelopathic 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 Torg-Pavlov ratio eliminates errors related to magnification, a problem with determination of spinal canal stenosis from direct measurements of plain cervical 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 patients with cervical spondylotic myelopathy requiring surgical decompression were compared with radiographs of 88 nonspondylotic, nonmyelopathic patients. The Torg-Pavlov ratio was computed for each level from C3 to C7. Results. The study showed that the Torg-Pavlov ratio is significantly smaller (P < 0.001) in myelopathic patients (mean 0.72 +/- 0.08) compared with the control patients (mean 0.95 +/- 0.14). This was so when individual levels 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 Torg-Pavlov ratio (P = 0.0001). Conclusions. The Torg-Pavlov ratio is significantly lower in patients with cervical spondylotic myelopathy compared with a nonspondylotic, nonmyelopathic population. It could possibly be used to predict the likelihood of developing cervical spondylotic myelopathy.