PDF(Pubmed)
Abstract：
To compare the biomechanical properties of several anterior pelvic ring external fixators with two new configurations in the treatment of Tile C pelvic fractures, in order to evaluate the effectiveness of the new configurations and provide a reference for their clinical application. A finite element model of a Tile C pelvic ring injury (unilateral longitudinal sacral fracture and ipsilateral pubic fracture) was constructed. The pelvis was fixed with iliac crest external fixator (IC), anterior inferior iliac spine external fixator (AIIS), combination of IC and AIIS, combination of anterior superior iliac spine external fixator (ASIS) and AIIS, and S1 sacroiliac screw in 5 types of models. The stability indices of the anterior and posterior pelvic rings under vertical longitudinal load, left-right compression load and anterior-posterior shear load were quantified and compared. In the simulated bipedal standing position, the results of the vertical displacement of the midpoint on the upper surface of the sacrum are consistent with the displacement of the posterior rotation angle, and the order from largest to smallest is IC, AIIS, ASIS + AIIS, IC + AIIS and S1 screw. The longitudinal displacement of IC is greater than that of the other models. The displacements of ASIS + AIIS and IC + AIIS are similar and the latter is smaller. In the simulated semi-recumbent position, the vertical displacement and posterior rotation angle displacement of the midpoint on the upper surface of the sacrum are also consistent, ranking from large to small: IC, AIIS, ASIS + AIIS, IC + AIIS and S1 screw. Under the simulated left-right compression load state, the lateral displacements of the highest point of the lateral sacral fracture end are consistent with the highest point of the lateral pubic fracture end, and the order from large to small is S1 screw, IC, AIIS, ASIS + AIIS and IC + AIIS, among which the displacements of S1 screw and IC are larger, and the displacements of ASIS + AIIS and IC + AIIS are similar and smaller than those of other models. The displacements of IC + AIIS are smaller than those of ASIS + AIIS. Under the simulated anterior-posterior shear load condition, the posterior displacements of the highest point of the lateral sacral fracture end and the highest point of the lateral pubic fracture end are also consistent, ranking from large to small: IC, AIIS, ASIS + AIIS, IC + AIIS and S1 screw. Among them, the displacements of IC and AIIS are larger. The displacements of ASIS + AIIS and IC + AIIS are similar and the latter are smaller. For the unstable pelvic injury represented by Tile C pelvic fracture, the biomechanical various stabilities of the combination of IC and AIIS are superior to those of the external fixators of conventional configurations. The biomechanical stabilities of the combination of ASIS and AIIS are also better than those of the external fixators of conventional configurations, and slightly worse than those of the combination of IC and AIIS. Compared with sacroiliac screw and conventional external fixators, the lateral stabilities of IC + AIIS and ASIS + AIIS are particularly prominent.
摘要：
比较几种骨盆前环外固定器与两种新配置治疗TileC骨盆骨折的生物力学特性。评价新构型的有效性,为其临床应用提供参考。建立了TileC骨盆环损伤（单侧纵向骶骨骨折和同侧耻骨骨折）的有限元模型。骨盆用髂骨外固定器(IC)固定,前髂下棘外固定器(AIIS),IC和AIIS的组合，髂前上棘外固定器（ASIS）和AIIS的组合，S1和5种型号的骶髂螺钉。前后骨盆环在垂直纵向载荷下的稳定性指标，对左右压缩载荷和前后剪切载荷进行量化和比较。在模拟双足站立位置，骶骨上表面中点垂直位移的结果与后旋转角度的位移一致，从最大到最小的顺序是IC，AIIS,ASIS+AIIS,IC+AIIS和S1螺钉。IC的纵向位移大于其他模型的纵向位移。ASIS+AIIS和IC+AIIS的位移相似，后者较小。在模拟的半卧位中，骶骨上表面中点的垂直位移和后旋转角位移也一致，从大到小的排名：IC，AIIS,ASIS+AIIS,IC+AIIS和S1螺钉。在模拟左右压缩载荷状态下，骶骨外侧骨折端最高点的侧向位移与耻骨外侧骨折端最高点一致，从大到小的顺序是S1螺丝，IC,AIIS,ASIS+AIIS和IC+AIIS，其中S1螺钉和IC的位移较大，ASIS+AIIS和IC+AIIS的位移与其他模型相似且较小。IC+AIIS的位移小于ASIS+AIIS的位移。在模拟前后剪切载荷条件下，骶骨外侧骨折端最高点和耻骨外侧骨折端最高点的后位移也一致,从大到小的排名：IC，AIIS,ASIS+AIIS,IC+AIIS和S1螺钉。其中,IC和AIIS的位移较大。ASISAIIS和ICAIIS的位移相似，后者较小。对于以TileC骨盆骨折为代表的不稳定骨盆损伤，IC和AIIS组合的生物力学各种稳定性优于常规配置的外部固定器。ASIS和AIIS组合的生物力学稳定性也优于常规配置的外固定器。比IC和AIIS的组合略差。与骶髂螺钉和常规外固定器相比,IC+AIIS和ASIS+AIIS的横向稳定性尤为突出。
