髋臼后柱骨折模型建立及髋臼后柱骨折钢板内固定和拉力螺钉内固定稳定性比较

Model establishment of posterior column fracture of the acetabulum and biomechanical evaluation of the stability between plate and lag screw internal fixation

背景:目前手术治疗已成为移位髋臼骨折治疗的金标准,累及髋臼后柱骨折的发生率较高,但选择何种内固定方法治疗髋臼后柱骨折较为适宜尚无定论。目的:建立髋臼后柱骨折模型,比较髋臼后柱骨折钢板内固定和拉力螺钉内固定的稳定性。方法:取成年防腐半骨盆标本20个,建立髋臼后柱骨折模型。将骨折模型标本随机分为钢板内固定组和拉力螺钉内固定组,进行轴向压缩实验,比较两种固定方式骨折断端的水平位移和剪切刚度。结果与结论:钢板内固定组和拉力螺钉内固定组骨折断端的水平位移分别为(1.64±0.17)mm和(1.70±0.20)mm;剪切刚度分别为(392.40±41.22)N/mm和(386.33±50.07)N/mm。两组间水平位移以及剪切刚度相比,差异均无显著性意义(P>0.05)。提示髋臼后柱骨折模型可用于评价髋臼后柱骨折不同内固定的稳定性,髋臼后柱骨折拉力螺钉内固定与钢板内固定的稳定性无显著性差异。

BACKGROUND： Surgery has become gold standard to treat fracture of acetabulum. The incidence of posterior column fracture of affected acetabulum is high. The appropriate treatment for posterior column fracture of acetabulum remains controversial. OBJECTIVE： To establish the model of posterior column fracture of acetabulum, and evaluate the stability of internal fixation with the plate and lag screw for the posterior column fracture of acetabulum. METHODS： A total of 20 preserved cadaveric semipelvic specimens were randomly divided into two groups. Models of isolated posterior column fracture of acetabulum were established. The models were fixed with plate or lag screw. Under vertical compression load, the horizontal displacements of the fracture site were measured and the shear rigidity of two fixation conditions was compared. RESULTS AND CONCLUSION： The horizontal displacements of the fracture site fixed with plate and lag screw were （1.64 ± 0.17） mm and （1.70 ± 0.20） mm. The shear rigidity fixed with plate and lag screw were （392.40 ± 41.22） N/mm and （386.33 ± 50.07） N/mm. The differences of both horizontal displacements and shear rigidity between the two groups were not significant （P〉 0.05）. The fracture model provides an ideal tool for biomechanical evaluation of the stability of internal fixation for the posterior column fracture of acetabulum. There was no significant difference in the stability of internal fixation with the plate and lag screw for the posterior column fracture of acetabulum.