CAJ | 학술논문

目的基于计算机控制的六自由度机器人全新试验装置,更好地模拟人体在自然状态下的复杂运动.比较3椎体4枚、5枚与6枚椎弓根钉固定术治疗胸腰椎爆裂骨折的生物力学稳定性效果.方法采用6具国人新鲜脊柱尸体标本(T_(11)～L_(13)),椎体切除法模拟失去前柱支持、完全不稳定L_1椎体爆裂骨折.试验分跨节段3椎体4枚椎弓根钉固定组、3椎体5枚椎弓根钉固定组和3椎体6枚椎弓根钉固定组.应用混合力-位移控制加载的六自由度机器人全新试验装置对标本进行前屈,后伸,左侧弯、右侧弯及左轴向旋转和右轴向旋转6种运动方式,对固定节段(T_(11)～L_3)的运动范围(ROM)进行测试并计算刚度值,比较各组间差异.结果随着螺钉数的增加,固定节段(T_(11)～L_3)的运动范围逐渐减小,刚度逐渐增大;轴向旋转时,6钉组、5钉组的运动范围小于4钉组(P<0.05),6钉组刚度大于4钉组(P<0.05)、5钉组刚度与4钉组的差异无统计学意义(P>0.05);6种不同加载方向下,6钉组与5钉组的运动范围与刚度的差异均无统计学意义(P>0.05);屈伸、侧弯状态下,3种不同固定方式之间差异不具有统计学意义(P>0.05).结论对于胸腰椎爆裂骨折,经骨折椎3椎体6枚钉或5枚钉的固定方式可以提高生物力学稳定性,稳定效果要优于传统的4枚钉固定,而6枚钉与5枚钉固定稳定性的差异不明显.
목적 기우계산궤공제적륙자유도궤기인전신시험장치,경호지모의인체재자연상태하적복잡운동.비교3추체4매、5매여6매추궁근정고정술치료흉요추폭렬골절적생물역학은정성효과.방법 채용6구국인신선척주시체표본(T_(11)～L_(13)),추체절제법모의실거전주지지、완전불은정L_1추체폭렬골절.시험분과절단3추체4매추궁근정고정조、3추체5매추궁근정고정조화3추체6매추궁근정고정조.응용혼합력-위이공제가재적륙자유도궤기인전신시험장치대표본진행전굴,후신,좌측만、우측만급좌축향선전화우축향선전6충운동방식,대고정절단(T_(11)～L_3)적운동범위(ROM)진행측시병계산강도치,비교각조간차이.결과 수착라정수적증가,고정절단(T_(11)～L_3)적운동범위축점감소,강도축점증대;축향선전시,6정조、5정조적운동범위소우4정조(P<0.05),6정조강도대우4정조(P<0.05)、5정조강도여4정조적차이무통계학의의(P>0.05);6충불동가재방향하,6정조여5정조적운동범위여강도적차이균무통계학의의(P>0.05);굴신、측만상태하,3충불동고정방식지간차이불구유통계학의의(P>0.05).결론대우흉요추폭렬골절,경골절추3추체6매정혹5매정적고정방식가이제고생물역학은정성,은정효과요우우전통적4매정고정,이6매정여5매정고정은정성적차이불명현.
Objective To compare the stability effect of the fixation segment using the new test system based robotics to simulate the complex human movement at natural state about the three-level fixa-tion by using four, five or six pedicle screws in treatment of thoracolumbar burst fractures. Methods Six human cadaveric spines were dissected from T_(11)-L_3. The inferior half part of L_1 vertebral bodies and L_1-L_2 dises were resected to mimie an unstable L_1 burst fracture with loss of anterior column support. Specimens were tested in accordance with the following order:intact, 4,5 and 6 pedicle screws fixation at the three-level fixation. The range of motion (ROM) of the fixation segment (T_(11)-L_3) was measured with the six-freedom degree robotics system controlled by mixed force and displacement during flexion, exten-sion, lateral bending and axial torsion, when the stiffness was calculated. One-way statistieal analysis was used for analyzing the collected data. Results With increased number of screws, the ROM of the fixa-tion segment (T_(11)-L_3) was gradually decreased and the stiffness gradually increased. The ROM under ax-ial rotation of six and five screws group became smaller than four screws group (P < 0.05). The stiffness under axial rotation of six screws group was higher than four screws group (P < 0.05). There was no sta-tistical difference between five screws group and four screws group in regard of the stiffness in axial rota-tion (P > 0.05). There were no significant differences in ROM and stiffness under six different loading directions between six screws group and five screws group (P > 0.05). No statistical difference was observed for three fixation modes in aspects of ROMs and stiffness under flexion-extension or lateral ben-ding (P > 0.05). Conclusions Three-level fixation of burst fractures with five or six screws offers im-proved biomechanical stability compared with traditional four screws fixation. But the difference is insig-nificant between six and five screws fixations.