Variations in the Torg-Pavlov Cervical Ratio with Regard to Age and Sex. A Comprehensive Anatomical and Morphometric Study on Contemporary Cadaveric Specimens

SUMMARY: The Torg-Pavlov ratio is a method used to detect cervical stenosis. A Torg-Pavlov ratio ≤0.80 suggests significant stenosis. This ratio is obtained by dividing the anteroposterior diameter of the cervical canal by the anteroposterior diameter of the vertebral body. The aim of this study was to evaluate these parameters and determine if there are significant differences with respect to sex and age. This is an anatomical and comparative study in which 1020 cervical vertebrae from C2-C7 from an osteological collection were evaluated. We determined the anteroposterior diameter from the vertebral body, the anteroposterior diameter from the vertebral canal and the Torg-Pavlov ratio. The pieces studied were divided into groups according to sex and age, resulting in six groups of study. A statistical analysis was made to determine the significance of the differences between sex and age groups. The size of the vertebral body diminished form C2-C3 and increased from C4-C7. The canal diminished form C2-C4 and increased from C5-C7. The Torg-Pavlov ratio decreased from C2-C7. The body and the canal were higher in men, while the Torg-Pavlov ratio was higher in women. With age, in men, the size of the body increased, the canal maintained its size, and the Torg-Pavlov ratio diminished significantly. In the group of women ≥60 years, the size of the body decreased, and the canal and the Torg-Pavlov ratio increased. In men, the Torg-Pavlov ratio is determined by the vertebral body and canal, because these did not show differences in most of the age groups. While in women, it is determined mostly by the spinal canal because it presented more variability between the age groups.