Fig. 2From: Application of dual-trajectory screws in revision surgery for lumbar adjacent segment disease: a finite element studyFour instrumentation constructs with different configurations for ASDz revision surgery. A Original internal fixation removed and traditional trajectory (TT) screws extended. B Original TT screws retained and dual-trajectory screws extended. C Original internal fixation removed and CBT screws extended. D Original CBT screws retained and dual-trajectory screws extended. E Configuration of the designed cage. F Bone graft and cage had successful interbody fusionBack to article page