镍钛记忆合金套合式交锁髓内钉的生物力学研究

Biomechanical evaluation of nickel-titanium shape-memory alloy enclosed interlocking intramedular nail

目的测定镍钛记忆合金套合式交锁髓内钉的生物力学指标,为进一步改进其临床应用提供依据。方法比较不锈钢交锁髓内钉、镍钛记忆合金套合式交锁髓内钉、6孔钢板及ender's钉对于6根新鲜肱骨标本在抗弯曲、抗扭转方面等方面的差异性。结果实验表明,镍钛记忆合金套合式交锁髓内钉在抗弯曲方面与钢板无显著性差异,优于ender's钉;在抗扭力方面与交锁髓内钉和钢板无显著性差异,优于ender's钉。结论记忆合金交锁髓内钉具有良好的生物力学特性,固定强度达到生物力学要求,而且应力遮挡小,弹性固定,记忆合金的弹性模量与骨相近,有利于骨折愈合,远端不需交锁,操作简单,便于推广利用。

Objective To study the biomechanical characteristics of Ni-Ti shape-memory alloy-enclosed interlocking intramedular nail Ni-Ti En for clinical application. Methods Six transverse fractures were induced in 6 fresh humeral shafts and fixed with Ni-Ti En, plate, interlocking intramedullary nail, and Ender nail, respectively. The specimens then underwent stress analysis for comparison of the bending strength, twisting force, and flexibility. Results The bending strength of Ni-Ti En was not significantly different from that of the plate and better than ender＇s nail; the twisting force of the interlocking intramedullary nail was comparable with the plate, but better than Ender nail. Conclusion Ni-Ti Enpossess good biomechanical property to meet the demand ofosteosynthesis, and its less stress protection, freedom of distant nail locking, flexibility and stable fixation may accelerate fracture healing.