Fig. 5.

Median ROM (dark plot) and NZ (bright plot), minimal and maximal values for flexion/extension in degrees. 1.) stable testing, 2.) testing after destabilization and cage insertion, 3a) additional non-constrained screw and rod system with lateral mass screws 3b) with pedicle screws instead of lateral mass screws; 4a) constrained screw and rod system with lateral mass screws 4b) with pedicle screws instead of lateral mass screws, 5.) 360°, 6.) anterior plate