Biomechanical comparisons of dynamic fixators with rod-rod and screw-spacer joints on lumbar hybrid fixation

•The hybrid fixation can protect the transition segment and suppress junctional problems.•The cable pretension of the screw-spacer system has a minor effect on the construct behavior.•The screw-spacer system transmits higher loads onto the transition disc.•The rod-rod system comparatively constrains the transition segment.•The rod-rod system induces higher compensations to the adjacent segments.