1.西南医科大学附属医院 骨科;2.四川省骨科置入器械研发及应用技术工程实验室;3.西南医科大学附属医院 临床医学研究中心
背景 骨盆松质骨含量丰富，普通骶髂经皮拉力修复骨质疏松的骶髂关节损伤易固定失效，开发能更有效把持松质骨的拉力钉具有重要意义。 目的 探究新型骶髂拉力钉的生物力学性能。 方法 用临床中常用的骶髂经皮拉力钉作为对照。使用聚氨酯材料模拟松质骨，利用Instron力学试验机测试新型骶髂拉力钉的抗拔出性能。采用骨盆标本，分析新型骶髂拉力钉修复正常站立姿态骶髂关节损伤的力学效果，测试固定的静态刚度和动态稳定性，以正常骨盆、骶髂经皮拉力钉-单钉修复、骶髂经皮拉力钉-双钉修复骶髂关节损伤为对照。 结果 拉力钉拔出后的聚氨酯材料破坏情况，新型骶髂拉力钉组的破坏更小。新型骶髂拉力钉抗拔出的有效把持位移平均约为（8.81±0.21）mm，显著大于骶髂经皮拉力钉平均位移（0.60± 0.02）mm。但骶髂经皮拉力的最大抗拔出力显著大于新型骶髂拉力钉的最大抗拔出力。骶髂关节损伤修复后的刚度，采用一枚骶髂新型骶髂拉力钉显著高于采用两枚普通骶髂经皮拉力钉。骶髂关节损伤组的位移振幅最大，为（0.995±0.021）mm；正常组的位移振幅第二大，为（0.520±0.011）mm；其余组别的位移振幅较为接近，但P均小于0.05，存在显著性差异。新型骶髂拉力钉修复的的动态稳定性最优，略优于骶髂经皮拉力钉双钉修复组，骶髂关节损伤组的稳定性最差。骶髂新型骶髂拉力钉能有效修复骶髂关节损伤。 结论 骶髂新型骶髂拉力钉能更有效的把持松质骨，具有一定的临床实用性。
Background: The pelvis contains abundant trabecular bone, and conventional percutaneous sacroiliac lag screws may exhibit fixation failure when used to repair sacroiliac joint injuries in patients with osteoporosis. The development of a screw that can effectively hold trabecular bone has significant clinical implications. Objective: To investigate the biomechanical performance of a newly developed sacroiliac lag screw. Methods: A commonly used percutaneous sacroiliac lag screw was used as a control. Polyurethane material was used to simulate trabecular bone, and the pullout resistance of the Novel Sacroiliac Spiral Blade Screw was tested using an Instron mechanical testing machine. Pelvic specimens were used to analyze the mechanical effects of the Novel Sacroiliac Spiral Blade Screw in repairing sacroiliac joint injuries under normal standing conditions. Static stiffness and dynamic stability were measured, with the normal pelvis, percutaneous sacroiliac lag screw - single screw repair, and percutaneous sacroiliac lag screw - double screw repair as controls. Results: The damage to the polyurethane material after screw extraction was less pronounced in the Novel Screw group. The average effective holding displacement for the Novel Screw was approximately (8.81±0.21) mm, significantly greater than the average displacement of the percutaneous sacroiliac lag screw (0.60±0.02) mm. However, the maximum resistance to pullout for the percutaneous sacroiliac lag screw was significantly higher than that for the Novel Screw. The stiffness after repair of sacroiliac joint injuries was significantly higher when using a single Novel Screw compared to using two percutaneous sacroiliac lag screws. The displacement amplitude was highest in the sacroiliac joint injury group, with a value of (0.995±0.021) mm. The normal group had the second highest displacement amplitude, with a value of (0.520±0.011) mm. The displacement amplitudes in the other groups were similar but significantly different with P-values less than 0.05. The dynamic stability was the best in the novel screw repair group, slightly better than the percutaneous sacroiliac lag screw - double screw repair group, and the worst in the sacroiliac joint injury group. The novel sacroiliac lag screw effectively repaired sacroiliac joint injuries. Conclusion: The novel sacroiliac lag screw can effectively hold trabecular bone and has practical clinical utility.