改良“叉”形钢板固定股骨髁部C_1型骨折的生物力学评价

Biomechanical evaluation of fork-shaped condyle plate in the fixation of the fracture of femoral condyle

目的 :评价改良“叉”形钢板对股骨髁部C1型骨折固定的生物力学性能。方法 :18具新鲜股骨下段及胫骨上段标本随机分成 3组 ,均制成股骨髁部C1型骨折模型 ,A组 :用改良“叉”形钢板固定 ;B组 :用股骨塑形钢板固定 ;C组 :用GSH钉固定。分别在MTS试验机上进行纵向压缩试验和轴向扭转试验 ,测量标本的纵向压缩位移、横向分离位移和扭转角度。结果 :改良“叉”形钢板、GSH钉、股骨塑形钢板固定组的纵向压缩位移分别为 (0 .41± 0 .0 3 )、(0 .3 8± 0 .0 1)、(0 .81± 0 .10 )mm ;横向分离位移分别为 (0 .2 0± 0 .0 1)、(0 .19± 0 .0 1)、(0 .3 0± 0 .0 1)mm ;扭转角度为 1.62°± 0 .0 7° ,1.69°± 0 .0 6° ,4.2 6°± 0 .72°。改良“叉”形钢板和GSH钉固定明显优于股骨塑形钢板 ,具有显著性差异 (P <0 .0 1)。结论 :改良“叉”形钢板用于固定股骨髁部C1型骨折 ,具有良好的生物力学性能 ,是治疗股骨髁部C1型骨折的一种较理想的内固定器械。

Objective: To evaluate the biomechanical stability of fork-shaped condyle plate in the fixation of C_1 fracture of femoral condyle. Methods: Eighteen fresh femoral and tibial specimens were divided into three groups randomly (A,B and C) and the models of C_1 fracture of femoral condyle were made in 18 cadaver femurs (C_1 of AO classification).Group A were fixed by fork-shaped condyle plate, group B by femoral plate and group C were fixed by GSH. These three different internal fixation methods were compared through experimental stress analysis on MTS .Results: The axis compress displacement of fork-shaped condyle plate, GSH and femoral plates were 0.41±0.03, 0.38±0.01 and 0.81±0.10mm respectively. Transverse separate displacements were 0.20±0.01, 0.19±0.01 and 0.30±0.01 mm. Torsion angles were 1.62±0.07, 1.69±0.06, 4.26±0.72 degrees. There were significant differences among these three different internal fixation methods ( P <0.001). Conclusion: This study shows that fork-shaped condyle plate provides biomechanical stability for the fixation of femoral condyle fracture.