腰椎前路椎间融合手术中关节突螺钉与椎弓根螺钉的生物力学比较

摘要

目的：探讨关节突螺钉（translaminar facet screw，TFS）与椎弓根螺钉（pedicle screw，PS）在前路椎间融合术（anterior lumbar interbody fusion，ALIF）中的力学稳定性，以及2种后路固定螺钉在 ALIF 对相邻节段的影响是否一致。方法采用正常成人新鲜尸体腰椎标本，将16具标本随机分为无手术组（intact）、ALIF 组、ALIF + TFS 组、ALIF + PS 组，在400N 压力和75N/ m 速率件下，比较各组刚度、相邻节段活动度和椎间盘压力。结果与 intact 组比较，ALIF 组在前屈度、侧弯度、轴向旋转度方面增加，而后伸度减少。在 ALIF + TFS 组、ALIF + PS 组和 ALIF 组的比较中，ALIF 组在前屈度、侧弯度、轴向旋转度方面明显增加，而 TFS 固定和 PS 固定提供的稳定性相当（差异无统计学意义），但 TFS 在椎间盘压力方面对相邻节段影响更小。结论 TFS 固定可以与 PS 固定提供同样的力学稳定性，TFS 固定是2节段 ALIF 理想的固定方法。%Objective To explore the mechanical stability of translaminar facet screw( TFS) and pedicle screw( PS)in anterior lumbar interbody fusion( ALIF)and whether the two posterior instrumentations have the same influence on the adjacent segments in two level anterior lumbar interbody fusion. Methods Normal adult human fresh corpses were used as spine samples,16 lumbar spines were randomed into no surgery group( intact),ALIF group,ALIF + TFS group and ALIF + PS group. Under 400N compressive preload and 75N/ m speed,comparisons were performed in the stiffness,motion range of adjacent segments and intervertebral disc pressure among different groups. Results Compared with intact group,ALIF group showed increase in flexion,lateral bending axial rotation,but decrease in extension. Comparisons among ALIF group,ALIF + TFS group and ALIF + PS group,ALIF group also showed increase in flexion,lateral bending,axial rotation,and the fixation stability by TFS and PS were similar, the difference was no significant,but TFS exerted less compressive stress on the adjacent segments of intervertebral discs. Conclusion TFS can provide the stability equivalent to PS in two-segment ALIF, TFS is the ideal choice in the operation.