The pedicles of lumbar vertebrae were measured both directly and
radiographically to determine the differences between the sexes and the
accuracy of radiographic measurement. The lumbar pedicles of cadavera of
forty-nine patients--twenty-four men and twenty-five women--who died
between the ages of sixty and ninety-eight years were measured directly and
on radiographs. The pedicles of lumbar vertebrae from fifty-one
patients--twenty-three men and twenty-eight women--between the ages of
twenty and fifty years who had low-back problems were measured on
radiographs and computerized tomographic scans. Comparison revealed that
the average transverse and sagittal diameters of the pedicles and the
distance from the posterior aspect of the laminar cortex to the anterior
aspect of the cortex of the vertebral body along the central axis of the
pedicles were 5 to 20 per cent greater in men, but the transverse and
sagittal angles of the pedicle did not differ significantly between the
sexes. Measurements on radiographs and computerized tomographic scans of
the transverse angles of the pedicles and of the distances from the
posterior aspect of the laminar cortex to the anterior aspect of the cortex
of the vertebral body from the second to the fifth lumbar vertebra were
greater than direct measurements, even without magnification. Direct
measurements of the diameters of the transverse and sagittal diameters of
the pedicle of the fifth lumbar vertebra, however, were greater than the
radiographic measurements.