髌骨骨折多种张力带固定方式的生物力学比较

Tension-band Wiring of Patellar Fractures: A Biomechanical Investigation

目的探讨改良AO张力带固定髌骨骨折,钢丝直径、固定方式对生物力学的影响。方法截取无病变新鲜冰冻膝关节标本8个,将髌骨横行截断,建立髌骨横行骨折标准创伤模型,以三种直径钢丝、四种不同张力带固定方式固定,通过测试比较固定后骨折间的最大压力及屈伸活动前、后骨折间的位移。结果进行统计学分析,比较髌骨骨折多种张力带固定方式的生物力学特点。结果直径1.2 mm的钢丝固定后骨折间最大初始压力更大,直径1.0 mm的钢丝固定疲劳试验后骨折间位移更小。双组平行钢丝张力带固定比单组钢丝张力带固定骨折间最大压力更大,位移更小,而单组单节张力带钢丝固定最大压力最小,位移最大。结论 AO改良克氏针钢丝张力带是固定髌骨横行骨折的有效方法,能满足骨折术后的早期功能锻炼。此外,通过调整克氏针张力带固定形状方式及固定钢丝的直径能增强其固定髌骨骨折的生物力学优点。

Objective To compare the biomeehanical properties of 4 constructs of tension band wiring made of 3 different sizes stainless steel-wires. Methods Transverse fractures were simulated in 8 adult cadaver knees and fixed with Kirschner wires in combination with figure-of-8 and parallel wire configurations of 3 different sizes stainless steel-wires. Biomeehanical stability were tested by interfragmentary compression and fracture gaps after the knees, 1000 cycles of flexion-extension motions. Results Fractures were more stable fixed with Kirsehner wires in combination with parallel than figure-of-8 wire configurations. The interfragmentary compressions were bigger when the fractures fixed with 1.2 mm diameter wires, but fracture gaps were narrower when the fractures fixed with 1.0 mm diameter wires. Conclusion Patella fractures can been fixed more stable with tension-band wiring by adjusting size and constuets of stainless steel-wire.