骶髂关节螺钉复合骶髂螺栓内固定对骨盆后环Denis-Ⅰ型骨折固定疗效的影响

Effect of internal fixation with sacroiliac joint screw combined with sacroiliac screw on Denis-Ⅰfracture fixation of posterior pelvic ring

目的比较单枚骶髂关节螺钉和单枚骶髂关节螺钉连接骶髂螺栓治疗骨盆后环Denis-Ⅰ型骨折固定疗效。方法将6具成人新鲜尸体非骨质疏松骨盆标本随机编号,保留骶髂复合体,剔除其余软组织,固定骨盆标本分别测定在施加0~800 N垂直载荷方向和0~8 N·m扭转载荷方向正常组骨盆后环的位移值,骨盆标本模拟Denis-Ⅰ型骨盆骶髂关节脱位,模型标本分别分组为:正常组、单枚骶髂关节螺钉固定组和单枚骶髂关节螺钉连接骶髂螺栓组分别固定骨盆后环Denis-Ⅰ型骨盆骶髂关节脱位,对固定后的骨盆标本测定其施加垂直载荷方向和扭转载荷方向骨盆后环的位移值。结果表明分别在垂直载荷(800 N)作用下,单枚骶髂关节螺钉连接骶髂螺栓固定组骨盆后环位移值略低于单枚骶髂关节螺钉固定组小,差异无统计学意义(P>0.05)。在扭转载荷(0~8 N·m)作用下,单枚骶髂关节螺钉连接骶髂螺栓固定组骨盆的位移值显著低于单枚骶髂关节螺钉固定组,差异有统计学意义(P<0.05)。结论生物力学测试表明在垂直载荷与扭转载荷作用下单枚骶髂关节螺钉连接骶髂螺栓固定组较单枚骶髂关节螺钉固定组更可增加骨盆后环的抗扭转载荷的强度。

Objective To compare the effect of single sacroiliac joint screw and a single sacroiliac joint screw connecting sacroiliac bolt in the treatment of Denis-Ⅰtype fractures of the posterior pelvis.Methods Six non-osteoporotic pelvic specimens of fresh adult cadavers were randomly numbered,and divided into normal group,single sacroiliac joint screw fixation group and single sacroiliac joint screw connecting sacroiliac bolt group.The sacroiliac complex of all the 6 cadavers were preserved,and the remaining soft tissues were removed.The fixed pelvic specimens were determined to be normal at 0~800 N vertical load direction and 0~8 N·m torsional load direction.Set the displacement value of the posterior pelvic ring,and pelvic specimens simulate Denis-Ⅰpelvic sacral fracture.All the specimens were fix the pelvic posterior ring sacroiliac joint fracture,and the displacement of the posterior pelvic ring in the direction of vertical load and torsional load on the fixed pelvic specimen were measured.Results Under the action of vertical load(800 N),the displacement value of the posterior pelvic ring was smaller in the single sacroiliac joint screw connecting sacroiliac screw fixation group than that in the single sacroiliac joint screw fixation group,but there was no statistically significant difference between the two groups(P>0.05).Under the torsional load(0~8 N·m),the displacement value of the pelvis was smaller in the single sacroiliac joint screw connecting sacroiliac screw fixation group than the single sacroiliac joint screw fixation group,and the difference between the two was statistically significant(P<0.05).Conclusion The results of biomechanical test showed that the single sacroiliac joint screw connecting sacroiliac bolt fixation can increase the strength of the posterior pelvic ring against torsional load more than the single sacroiliac joint screw fixation under the action of vertical load and torsional load.