Measurement of the anterior body height and focal kyphotic angle. a, anterior body height of the VCF; b, posterior vertebral height of the adjacent cranial vertebra; c, posterior vertebral height of the adjacent caudal vertebra; p, estimate of the posterior body height of the VCF (average of b and c). The anterior body height ratio is a/p; U, the line parallel to the upper endplate of the cranial vertebra (red line); L, the line parallel to the lower endplate of the caudal vertebra (blue line). The focal kyphotic angle is the intersecting angle of U and L.