髋臼横形骨折内固定稳定性的生物力学评估

Biomechanical evaluation of transverse acetabular fracture fixation

目的探讨髋臼横形骨折的最有效内固定方法。方法用左右配对的24个髋关节标本,按不同的内侧顶弧角截骨,建立横形骨折模型。分别用前柱钢板加后柱螺钉(P+S)、前柱螺钉加后柱钢板(S+P)、后柱双钢板(N/P×2)及前柱单钢板(P/N)等4种方法对骨折模型进行内固定,然后加载垂直压缩载荷,通过测试骨折的纵向、水平位移和轴向刚度,以比较各内固定方法的稳定性。结果4种内固定方法中,在加载800N时,S+P、P+S、N/P×2和P/N组的骨折纵向位移分别为3.99mm、4.09mm、5.07mm和5.66mm,平均水平位移分别为:0.015mm、0.016mm、0.022mm和0.025mm,平均轴向刚度分别为:205.77N/mm、207.52N/mm、162.3N/mm和146.67N/mm。F检验显示前、后各2组间差异有显著意义(P<0.05)。结论髋臼横形骨折内固定以前柱钢板+后柱螺钉、前柱螺钉+后柱钢板方法较理想,其中前柱螺钉+后柱钢板最佳。

Objective To conduct a biomechanical evaluation of the four internal fixation methods to treat transverse acetabular fracture and find the b est one. Methods The transverse acetabular fracture models were created by osteo tomy in 12 pairs of embalmed cadaveric hip joints, and fixed with one of the fou r different methods: an anterior column plate (P/N), an anterior column plate w ith a posterior column screw (P+S), a posterior column plate with an anterior screw (S+P) and two posterior column plates (N/P×2). The biomechanical stabi lity was evaluated on longitudinal displacement, level displacement and stiffnes s measurements for fixed fracture fragments which were under 800 Newton vertical compression load. Results The longitudinal displacement in S+P was 3.99mm, in P+S 4.09mm, in N/P×2 5.07mm and in P/N 5.66mm; the level displacement in S+P was 0.015mm, in P+S 0.016mm, in N/P×2 0.022mm and in P/N 0.025mm; the average stiffness in S+P was 205.77N/mm, in P+S 207.52N/mm, in N/P×2 162.36N/mm and i n P/N 146.67N/mm. There were significant differences between the groups of S+P and P+S and the groups of N/P×2 and P/N (P< 0.05). Conclusion S+P and P+S of the four internal fixation methods can be better ways for treatment of transv erse acetabular fractures, and S+P is the best.