三种内固定物固定骨盆后环损伤稳定性的生物力学比较

 目的 比较张力带接骨板、2枚骶髂螺钉和可调式微创骨盆后环接骨板治疗骨盆后环纵 行骨折的固定效果。方法选择 8具成年男性非骨质疏松性骨盆标本, 保留骶髂复合体, 剔除其余软组 织, 制作右侧骶骨纵行骨折模型;±次应用张力带接骨板、2枚骶髂螺钉、可调式微创骨盆后环接骨板行 规范化固定。将标本以坐位固定于生物力学试验机, 首先以 20 N/s的速度对标本施加 0~620N的垂直 负荷, 记录标本移位程度;然后以 0.1°/s的角速度加载扭转负荷, 记录扭转角度及对应的扭矩。采用方差 分析比较不同内固定物的固定效果。结果 在垂直负荷作用下, 可调式微创骨盆后环接骨板固定骨盆 的移位与 2枚骶髂螺钉固定骨盆的移位无明显差别, 两者移位均小于张力带接骨板固定骨盆的移位。 在扭转负荷下, 可调式微创骨盆后环接骨板固定骨盆的扭矩与 2枚骶髂螺钉固定骨盆的扭矩无明显差 别, 两者均大于张力带接骨板固定骨盆的扭矩。结论 在垂直负荷和扭转负荷作用下, 可调式微创骨盆 后环接骨板固定骨盆的稳定性与 2枚骶髂螺钉固定效果相同, 两者均优于张力带接骨板。

Biomechanical comparison of the stability of posterior pelvic ring disruptions fixed with three kinds of internal fixator

Objective To compare the stability of vertical fractures of posterior pelvic ring fixed with tension band plate (TBP),two sacroiliac(SI) screws and minimally invasive adjustable plate (MIAP) for posterior pelvic ring.Methods Eight adult male pelvic specimens without osteoporosis were selected.The sacroiliac complex was retained and other soft tissue was removed.The right sacral vertical fractures were made.The fractures were reduced anatomically and fixed in turn with TBP,two SI screws and MIAP.The pelvic specimens were fastened to the biomechanical testing machine in sitting position.Vertical load,ranging from 0 to 620 N,was applied on specimens at a speed of 20 N/s and the displacement was recorded.Then the specimens were exposed to torsional load at a speed of 0.1 degree/s.The rotation degree and corresponding torque were recorded.Analysis of variance was employed to analyze the data.Results Under vertical load,the displacement of the pelvis fixed with MIAP was similar to that fixed with two SI screws.The displacement of the pelvic fractures fixed with either MIAP or two SI screws was smaller than that fixed with TBP.Under torsional load,the torque measured on the pelvis fixed with MIAP was similar to that fixed with two SI screws.The torque measured on the pelvic fractures fixed with either MIAP or two SI screws was greater than that fixed with TBP.Conclusion The posterior pelvic ring disruptions fixed with MIAP is as stable as that fixed with two SI screws,both with better stability than that fixed with TBP,under both vertical load and torsional.