Fig. 3.

Mean angular range of motion over the entire specimen (T7–T12) was significantly reduced after instrumenting the two fusion from T9 to T11 (*p < 0.0001) and was further reduced in all bending modes, except for extension after the fusion was extended to T8–T9 (UIV) with either hooks, hybrid, or pedicle screws (^# p < 0.05). Average total specimen motion was significant greater in torsion when bilateral hooks were used in comparison with hybrid and bilateral pedicle screws (^† p < 0.05). Errors bars represent ± 1 standard deviation. Abbreviation: UIV, upper-instrumented vertebrae.