Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
A, Six reference lines representing the four sides and two diagonals of a vertebral body. B, Each reference line is defined by three parameters: length, average distance from the center of rotation, and the angle extended at the center of rotation.
