ABSTRACT
BACKGROUND:Santoni put forward the cortical bone trajectory technology by changing the traditional pedicle screw placement for lumbar internal fixation in order to obtain better control of the screw and bone in 2009. OBJECTIVE:To analyze biomechanical stability of cortical bone trajectory system in the lumbar fusion. METHODS:Twenty fresh newborn calf L3/4, L5/6 motion segment specimens were obtained, and their ranges of motion were detected under different states, as normal controls. Subsequently, twenty samples were divided into cortical bone trajectory screw group and traditional pedicle screw group, which underwent cortical bone trajectory screw fixation combined with posterior lumbar fusion and traditional pedicle screw fixation combined with posterior lumbar fusion, respectively. Without destruction, ranges of motion were detected under different states in both groups. In the revision group, after the test in the traditional pedicle screw group, screw was withdrawn, and cortical bone trajectory screw was used to detect its range of motion under different states. RESULTS AND CONCLUSION:Ranges of motion at bending to the left and right, anteflexion, posterior extension and axial rotation were significantly lower in the cortical bone trajectory screw group and traditional pedicle screw group than in the normal control group (P0.05). These results confirmed that cortical bone trajectory technology combined with posterior lumbar fusion can obtain identical stability as the traditional pedicle screw fixation combined with posterior lumbar fusion. Simultaneously, it is a new choice for revision after traditional pedicle screw fixation.