Table 2.

Landmarks and measurements used to determine cervical vertebral morphology.

Landmarks/ Measurements	Definition
C2lp	The most posterior point of C2 on the lower border
C2la	The most anterior point of C2 on the lower border
C2m	The deepest point of the concavity at the lower border of C2
C2Conc	The distance between C2m and the line connecting C2lp and C2la
C3up	The most posterior point of C3 on the upper border
C3ua	The most anterior point of C3 on the upper border
C3lp	The most posterior point of C3 on the lower border
C3la	The most anterior point of C3 on the lower border
C3m	The deepest point of the concavity at the lower border of C3
C3Conc	The distance between C3m and the line connecting C3lp and C3la
C3BAR	Ratio between the length of the base (distance C3lp − C3la) and the anterior height (distance C3ua − C3la) of the body of C3.
C4up	The most posterior point of C4 on the upper border
C4ua	The most posterior point of C4 on the upper border
C4lp	The most posterior point of C4 on the lower border
C4la	The most anterior point of C4 on the lower border
C4m	The deepest point of the concavity at the lower border of C4
C4Conc	The distance between C4m and the line connecting C4lp and C4la
C4BAR	ratio between the length of the base (distance C4lp − C4la) and the anterior height (distance C4ua − C4la) of the body of C4