髋臼横行后壁骨折不同内固定方式的生物力学研究

A Biomechanical Study on Different Internal Fixation of Acetabular Transverse Posterior Wall Fractures

目的探讨不同内固定方式在髋臼横行后壁骨折内固定中的生物力学稳定性,为临床应用不同内固定方式治疗髋臼横行后壁骨折提供可靠的生物力学依据。方法 20具成人防腐尸体标本共40具半髋臼标本随机数字表法分为4组,每组5具完整骨盆。A组:后柱重建钢板联合后壁螺钉固定;B组:后柱重建钢板联合前柱拉力螺钉及后壁螺钉固定;C组:前柱重建钢板联合后柱重建钢板及后壁拉力螺钉固定;D组:后柱锁定重建钢板。应用生物力学实验机分别对各组加载至骨折端固定失败(移位>2mm)并记录各组的最大载荷,比较4组的生物力学稳定性。结果髋臼横行后壁骨折4种不同的内固定方式所能承载的最大载荷分别为:A组(823.89±106.27)N;B组(1 041.38±125.66)N;C组(1 210.19±116.27)N;D组(1 037.89±108.67)N,各组两两比较:A组所承载的最大载荷小于B、C、D组,差异有统计学意义(F=15.98;P=0.027);C组所承载的最大载荷大于B、D组,差异有统计学意义(P=0.015);B、D组差异无统计学意义(P=0.571)。结论内固定治疗髋臼横行后壁骨折时,应用前后柱双钢板、后柱锁定重建钢板及后柱重建钢板联合前柱拉力螺钉固定的生物力学稳定性均优于后柱单重建钢板,其中前后柱双钢板固定的稳定性更强;后柱锁定重建钢板与后柱重建钢板联合前柱拉力螺钉所承载的最大载荷相似。

Objective To study the biomechanical stability of different internal fixation in acetabular transverse posterior wall fractures and offer reliable biomechanical basis for applying different fixation to the clinical treatment of acetabular transverse posterior wall fractures. Methods 40 half acetabular specimens of 20 antiseptic adult cadavers were randomly divided into four groups and each group consisted of five complete pelvis. The four groups were Group A with posterior column reconstruction plate combined with the rear wall screws, Group ]3 with posterior column reconstruction plate combined with anterior column lag screw and the rear wall screws, Group C with the anterior column reconstruction plate combined with posterior column reconstruction plate and posterior wall of steel lag screws and Group D with locking reconstruction plate. The biomechanical testing machine was used to test the maximum load of each group by causing the fixation failure （displacement〉2mm） in the fracture site. Then the biomechanical stability of the four groups was compared and analyzed. Results The maximum loads of four different fixation in the acetabular transverse posterior wall fracture were （823.89 ±106.27）N in Group A, （1 041. 38±125.66）N in Group B, （1 210.19±116.27）N in Group C, and （1 037.89±108.67）N in Group D. The results of pairwise comparisons showed that the maximum load of Group A was significantly less than those of Group B, C and D respectively （F=15.98; P=0. 027）, the maximum load of Group C was significantly greater than those of Group B and D respectively .（P=0. 015）, and there were no significant differences in the maximum load between Group B and D （P=0. 571）; Conclusion The biomechanical stability of double plates in both anterior and posterior columns, posterior column locking reconstruction plate, and posterior column reconstruction plate combined with anterior column lag screw is better than that of posterior column single reconstruction plate in the treatment of acetabular transverse posterior wall fractures. The fixation with double plates in both anterior and posterior columns is the most stable, and the maximum load of the posterior column locking reconstruction plate is similar to that of posterior column reconstruction plate combined with anterior column lag screw.