Sagittal evaluation of elemental geometrical dimensions of human vertebrae.

Geometrical configuration and dimensions of the human vertebra were investigated using radiographs of 157 normal healthy adult men. Measurements were based on five bony reference points, which can be defined in radiographs. The measurements permit the determination of nine dimensions that can be used for anthropometrical evaluation of the cervical and lumbar vertebrae. A simplified model of the vertebra in the sagittal plane is presented and serves as a basis for the geometrical measurements. In the cervical region, average width exceeded average height of vertebral bodies C3 to C7, while in C2 the average width was smaller than the average height; C7 was the longest and C3 the shortest cervical vertebra. In the lumbar region, average width exceeded average height of the vertebral bodies. Values for width and height did not differ significantly from L1 to L5; L3 was the longest and L5 the shortest lumbar vertebra.