CAJ | 학술논문

目的比较胸腰椎骨折后路单节段椎弓根钉固定与结合骨水泥强化固定的生物力学效果.方法在8具新鲜小牛胸腰椎标本(T11～L3)的L1椎体上制作不完全爆裂骨折模型.标本依次行单节段椎弓根钉固定及单节段椎弓根钉固定+骨水泥强化固定.对标本施加扭矩为4 Nm的疲劳载荷共2 000次,加载频率为0.5 Hz.经脊柱三维运动测量系统测量完整、骨折、固定和周期性加载后固定节段前屈、后伸、左侧屈、右侧屈、左旋转和右旋转运动时固定节段的角位移运动范围(ROM).结果两种固定状态及疲劳后各方向ROM均明显小于正常及骨折状态(P<0.05);单节段椎弓根钉固定结合骨水泥强化固定状态前屈、后伸、侧屈、旋转ROM分别为0.40°、0.53°、0.86°、0.55°,疲劳后前屈、后伸、侧屈、旋转ROM变化值分别为0.10°、0.07°、0.19°、0.08°,均小于单纯单节段椎弓根钉固定组,尤其在旋转和前屈方向,差异有统计学意义(P<0.05).结论两种固定方式均可重建脊柱骨折的即刻稳定性并具有良好的抗疲劳载荷效果.但在前屈和旋转方向,单节段椎弓根钉固定并骨水泥强化优于单纯单节段椎弓根钉固定.
목적 비교흉요추골절후로단절단추궁근정고정여결합골수니강화고정적생물역학효과.방법 재8구신선소우흉요추표본(T11～L3)적L1추체상제작불완전폭렬골절모형.표본의차행단절단추궁근정고정급단절단추궁근정고정+골수니강화고정.대표본시가뉴구위4 Nm적피로재하공2 000차,가재빈솔위0.5 Hz.경척주삼유운동측량계통측량완정、골절、고정화주기성가재후고정절단전굴、후신、좌측굴、우측굴、좌선전화우선전운동시고정절단적각위이운동범위(ROM).결과 량충고정상태급피로후각방향ROM균명현소우정상급골절상태(P<0.05);단절단추궁근정고정결합골수니강화고정상태전굴、후신、측굴、선전ROM분별위0.40°、0.53°、0.86°、0.55°,피로후전굴、후신、측굴、선전ROM변화치분별위0.10°、0.07°、0.19°、0.08°,균소우단순단절단추궁근정고정조,우기재선전화전굴방향,차이유통계학의의(P<0.05).결론 량충고정방식균가중건척주골절적즉각은정성병구유량호적항피로재하효과.단재전굴화선전방향,단절단추궁근정고정병골수니강화우우단순단절단추궁근정고정.
Objective To compare the biomechanical properties of mono-segTnent pedicle instru-mentation and its combination with bone cement fixation in treatment of thoracolumbar fractures. Meth-ods Eight fresh specimens of calf spines ( T11 -L3 ) were used for development of incomplete burst frac-ture models at the vertebral body of L1. Mono-segment pedicle instrumentation and its combination with vertebroplasty were respectively applied in each specimen subsequently to restore spinal stability. A cyclic loading with pure moment of 4 Nm was applied to specimens, with load frequency of 0.5 Hz for 2 000 cy-cles. Range of motion (ROM) at flexion/extension, left/right lateral bending and left/right axial rotation of the fixated segment at different status of intact, injury, fixation and cyclic loading was determined by spinal three-dimensional instability test system. Results ROM after treatment with two fixation tech-niques and that at different directions after cyclic loading were distinctly smaller than that of intact and fractured models (P <0.05 ). Under mono-segment pedicle instrumentation combined with bone cement fixation, ROM at flexion, extension, lateral bending and axial rotation was 0.40°, 0. 53°, 0.86° and 0.55° respectively and that after cyclic loading was 0.10°, 0.07°, 0.19° and 0.08°respectively, which were all lower than those of monosegmental fixation, especially at flexion and axial rotation, with statisti-cal difference (P <0.05 ). Conclusions Both fixation techniques can provide instant stabihty of the fractured spine and have good fatigue resistance effect. However, mono-segment pedicle instrumentation is inferior to mono-segment pedicle instrumentation plus bone cement fixation in treatment of fractured verte-bral body at flexion and axial rotation.