ABSTRACT
Objective To compare the initial stability between anterior transpedicular screw (ATPS) fixation,anterior plate (AP) fixation and combining anterior and posterior (CAP) fixation for subaxial cervical three-column injury.Methods Six specimens of cervical spine were prepared.After measurement of the range of motion (ROM) of the intact cervical spine,the specimens were made into models of three-column injury.After the models were simulatively reconstructed using an anterior cervical cage,they were stabilized by ATPS,AP and CAP.After the ROMs of the models in the 3 fixation states were measured,the data were normalized by standardizing them to the intact state ROM which was set at 100％.The normalized ROMs of the models in the 3 fixation states were compared.Results The normalized ROMs of AP fixation state in flexion,extension,lefi lateral bending,right lateral bending,left axial rotation and right axial rotation were 119.68±8.34％,119.63±6.74％,115.20±7.91％,117.47±7.81％,120.67±5.99％ and 112.35 ± 8.42％,respectively,significantly larger than those of the intact state (P ＜ 0.05).The normalized ROMs of the other 2 states in all directions were significantly smaller than those of the intact state (P ＜0.05).The normalized ROM of ATPS state in flexion was 87.48 ± 5.31％,significantly larger than that of CAP state (69.60 ± 2.06％) (P ＜ 0.05).There were no significant differences between the normalized ROMs of ATPS state and those of CAP state in extension (65.53 ± 4.36％ versus 67.17 ± 3.10％),in left lateral bending (82.13 ± 2.85％ versus 82.30 ±4.69％),in right lateral bending (81.78 ± 3.42％ versus 81.27 ± 2.79％),in left axial rotation (83.20 ± 2.30％ versus 82.95 ± 2.40％),or in right axial rotation (83.03 ± 1.30％ versus 83.60 ± 6.56％) (P ＞ 0.05).Conclusions In subaxial cervical three-column injury,the initial stability of ATPS fixation may be superior to that of AP fixation and similar to that of CAP fixation.We believe that ATPS can provide enough initial stability for subaxial cervical three-column injury.