经椎间孔椎间融合术联合单侧椎弓根螺钉固定的生物力学研究

摘要

目的：研究经椎间孔椎间融合术( TLIF)联合单侧椎弓根螺钉固定的生物力学稳定性及刚度。方法新鲜小牛下腰椎标本8具,加工成L4~5功能单位,测定其在屈伸、侧弯、轴向旋转6个方向上的运动范围值(ROM)及刚度值。依序测试：正常组(A组),单侧部分关节突切除加椎间盘摘除组(B组),单侧椎弓根螺钉固定组( C组),单侧椎弓根螺钉固定联合置入单枚cage组( D组),双侧椎弓根螺钉固定联合置入单枚cage组( E组)。结果与A组比较,B组ROM明显增加,而刚度值明显减小；C、D、E组ROM减小,但刚度值增加,差异均有统计学意义(P<0．05)。与B组比较,C、D、E组ROM明显减小,而刚度值明显增加,差异有统计学意义(P<0．05)。与C组比较,D、E组ROM减小,刚度值增加,差异有统计学意义(P<0．05)。与D组比较,E组刚度值增加,但前屈、侧弯、旋转5个运动方向ROM减小,差异均有统计学意义( P<0．05),后伸运动方向ROM差异无统计学意义(P>0．05)。结论 TLIF术式椎间融合联合单侧椎弓根螺钉固定可获得良好的生物力学稳定性,置入单枚cage较椎间植入自体骨的稳定性更高。%Objective To assess the biomechanical stability and stiffness of simulated transforaminal lumbar inter-body fusion ( TLLF) plus unilateral pedicle screw fixation. Methods Eight functional spinal units( L4~5 ) from fresh bovine lumbar spines specimens were investigated the range of motion( ROM) and stiffness in flexion, extension, lat-eral bending and axial rotation. Sequence testing:group A( normal low lumbar vertebrae specimen);group B( unilat-eral partial facetectomy with discectomy);group C( unilateral pedicle screw fixation);group D( single cage plus uni-lateral pedicle screw fixation); group E(single cage with bilateral pedicle screw fixation). Results Compared to group A, the ROM of group B significantly increased in all directions, but the stiffness of group B significantly de-creased, the ROM of group C,D,E significantly increased in all directions, but the stiffness significantly increased, the difference was statistically significant(P<0. 05); Compared to group B, the ROM of group C,D and E signifi-cantly increased in all directions, but the stiffness significantly increased, the difference was statistically significant ( P<0. 05);Compared to group C, the ROM of group D and E significantly decreased in all directions, but the stiff-ness significantly decreased, the difference was statistically significant(P<0. 05); Compared to group D, the stiff-ness of group E significantly decreased. The ROM of group E in flexion, left/right bending, and left/right rotation were significantly decreased(P<0. 05), but there was no significantly different in extension (P>0. 05). Conclu-sions TLIF plus unilateral pedicle screw fixation can offer dependable stability of the lumbar vertebrae. Single ana-tomical cage can be more stable and reliable than impacted morselized bone graft.