不同固定位置及方向张力带钢板对重建骨盆后环稳定性的影响

Influence of different fixed positions of tension band plate on stability of reconstructed posterior pelvic ring

目的比较3种不同固定位置及方向的张力带钢板对重建骨盆后环稳定性的影响。方法选取8具成人防腐骨盆标本,制成不稳定性骨盆后环损伤模型。每具骨盆标本后环用3种不同位置张力带钢板进行固定,固定位置1:钢板固定在双侧髂后上棘水平、钢板两端指向耻骨联合;固定位置2:钢板固定在髂后上棘上方水平、钢板两端指向前方;固定位置3:钢板固定在髂后上棘下方水平、钢板两端指向前上方。将固定好的骨盆标本置于生物力学试验机上,分别依次予以0~600 N的垂直加载和0~8 N·m扭转加载,测量并记录整体骨盆垂直位移和扭转角度,计算骨盆的轴向刚度和扭转刚度;在垂直加载时测量并记录损伤侧骶髂关节在垂直、水平和前后方向上骶骨与髂骨的相对位移以及骶骨相对于髂骨在矢状面上的旋转。结果在0~600 N垂直载荷下,固定位置1的整体骨盆环垂直位移最小(P均<0. 05),轴向刚度最接近完整骨盆。在0~8 N·m扭转载荷下,固定位置1的扭转角度最小(P均<0. 05),扭转刚度最接近完整骨盆。在0~600 N的垂直载荷下,骨盆后环骶髂关节在垂直、左右和前后方向上位移以及在矢状面上的旋转位移,固定位置1均最小(P均<0. 05)。结论在垂直和扭转载荷下,张力带钢板选择在髂后上棘水平、钢板两端指向耻骨联合固定,可为骨盆环的整体固定及后环固定提供更好的生物力学稳定性。

Objective To compare the effects of three different fixed positions of tension band plate on the stability of reconstructed posterior pelvic ring.Methods Eight adult pelvic specimens were selected to make the damage models of unstable pelvic ring.Each damage model was fixed with tension band plates at three different positions.The fixed position 1:the plate was fixed at the posterior superior iliac spine and both ends of the plate were pointed to the symphysis ossium pubis;the fixed position 2:the plate was fixed above the posterior superior iliac spine and both ends of the plate were pointed to the front horizontally;fixed position 3:the plate was fixed below the posterior superior iliac spine,and both ends of the plate were pointed to the anterosuperior.The fixed damaged pelvis specimens were placed on the biomechanical test machine,and the vertical loading of 0-600 N and the torsion loading of 0-8 N·m were respectively performed,the vertical displacement and torsion angle of the whole pelvis model were measured and recorded,and the axial rigidity and torsion rigidity of the pelvis model were calculated.The relative displacement between the sacrum and the iliac bone in the vertical,horizontal and posteroanterior direction of the injured sacroiliac joint and the rotation of the sacrum on the sagittal plane relative to the iliac bone were measured and recorded under the vertical loading.Results Under the vertical load of 0-600 N,the vertical displacement of the integral pelvic model fixed with fixed position 1 was the smallest(P<0.05),and the axial stiffness was the closest to the intact pelvis.The torsion angle of the pelvic model fixed with fixed position 1 was the smallest under the 0-8 N·m torsion load(P<0.05),and the torsion rigidity was the closest to the intact pelvis.Under the vertical load of 0-600 N,in term of the relative displacement between the sacrum and the iliac bone in the vertical,horizontal and posteroanterior direction of the injured sacroiliac joint and the rotation of the sacrum on the sagittal plane relative to the iliac bone,the model fixed with fixed position 1 was the smallest(P<0.05).Conclusion Under vertical and torsional loads,the effect of tension band plate fixed at the posterior superior iliac spine with both ends of the plate to the symphysis ossium pubis is the best,which provides better biomechanical stability for the overall fixation and posterior ring fixation of the pelvic ring.