四种不同内固定治疗胫骨平台后外侧剪应力骨折的生物力学研究

目的 比较4种不同内固定方式治疗胫骨平台后外侧剪应力骨折的生物力学性能.方法 将40具人工合成右侧胫骨模型根据胫骨平台后外侧剪应力骨折的形态学特征建立胫骨平台后外侧剪应力骨折模型,随机分成4组(n=10):A组采用前外侧2枚拉力螺钉固定,B组采用前内侧有限接触动力加压钢板(LC-DCP)固定,C组采用外侧解剖锁定钢板固定,D组采用后外侧支撑钢板固定.测量4组在轴向载荷500、1000及1500 N下的垂直位移和最大失效载荷.结果 A、B、C、D组在500 N载荷下骨折块的相对位移分别为(0.459±0.045)、(0.365±0.035)、(0.264±0.025)、(0.128±0.018)mm,在1000 N载荷下骨折块相对位移分别为(1.058±0.091)、(0.882±0.053)、(0.551±0.053)、(0.440±0.068)mm,在1500 N载荷下骨折块的相对位移分别为(1.559±0.097)、(1.466±0.079)、(1.291±0.077)、(0.832±0.130)mm,同一载荷下D组与其他3组比较差异均有统计学意义(P＜0.05).A、B、C、D组失效载荷分别为(1870±156)、(2520±186)、(2816±190)、(3465±210)N,D组与其他3组比较差异均有统计学意义(P＜0.05).结论 后外侧支撑钢板固定组抗载荷力学性能最佳,对固定胫骨平台后外侧剪应力骨折有明显的生物力学优势.

Biomechanical analysis of various fixations for the posterolateral shearing tibial plateau fracture

Objective To compare and analyze the biomechanical strengths of 4 different fixations for the posterolateral shearing tibial plateau fracture. Methods The posterolateral shearing fracture models were created in 40 synthetic tibia (SYNBONE, right) and randomly assigned into 4 groups. Group A was instrumented with 2 lag screws, group B with anteromedial LC-DCP, group C with lateral locking plate,and group D with posterolateral buttress plate. Vertical displacements of the posterolateral fragments and failure loads were measured under axial loads from 500 N to 1500 N. Results The vertical displacements in groups A, B, C and D were respectively(0. 459 ±0. 045) mm, (0. 365 ±0. 035) mm, (0. 264 ±0. 025)mm and (0. 128 ± 0. 018) mm under axial loads of 500 N, (1. 058 ± 0. 091 ) mm, (0. 882 ± 0. 053 ) mm,(0.551±0.053) mm and (0.440±0.068) mm under 1000 N, and (1.559±0.097) mm, (1.466±0. 079) mm, (1. 291 ±0. 077) mm and (0. 832 ±0. 130) mm under 1500 N. The differences between the 4 groups were statistically significant ( P ＜ 0. 05) . The loads to failure in groups A, B, C and D were respectively (1870 ± 156) N, (2520 ± 186) N, (2816 ± 190) N and (3465 ±210) N. The differences between the 4 groups were statistically significant ( P ＜ 0. 05 ). Conclusion The posterolateral buttress plate may be the biomechanically best fixation method for the posterolateral shearing tibial plateau fracture.