不同固定方式对儿童肱骨近端不同高度骨折稳定性影响

目的 通过有限元方法比较不同固定方式对不同高度的不稳定型儿童肱骨近端骨折稳定性的影响。 方法建立不同高度(P1、P2、P3、P4)的儿童肱骨近端横行骨折模型,使用弹性髓内针(髓内针组)及不同构型的克氏针进行固定(4 针组、3A 组、3B 组),然后导入 ANSYS 2019 中,模拟上肢重力以及前屈、后伸、内收、外展、内旋、外旋 7 种工况,分析肱骨远端最大位移、内固定最大应力的平均值。 结果 所有高度肱骨远端最大位移的平均值均在 4 针组最小,内固定物最大应力的平均值在 P1 和 P4 高度时弹性髓内针最低,P2 和 P3 高度则是 4 针组。 结论 弹性髓内针固定在骨折面较低时优于 3 针固定,4 枚克氏针则在所有高度优于弹性髓内针固定。

Effects of Different Fixation Methods on Stability of Pediatric Humeral Proximal Fractures at Varying Heights

Objective To compare the effects of different fixation methods on stability of pediatric humeral proximal unstable fractures at different heights by using the finite element method. Methods Different pediatric humeral transverse fracture models at varying heights were created and fixed by elastic stable intramedullary nailing (ESIN) and Kirschner wire with different configurations. These models were imported into ANSYS 2019 to simulate seven working conditions, namely, the upper limb gravity, anterior flexion, posterior extension, adduction, extension, internal rotation and external rotation. The mean maximum displacement of the distal humerus and the mean maximum stress of the internal fixation were analyzed. Results The mean maximum displacement of the distal humerus was lowest in four-pin group at each height, while the average maximum stress on internal fixation was the smallest for ESIN at P1 and P4 heights. For P2 and P3 heights, the four-pin group had the lowest stress levels. Conclusions ESIN is superior to 3-pin fixation in lower fracture planes, while 4-pin Kirschner wires are more effective than ESIN at all heights.