无柄解剖形人工髋关节生物力学实验研究

本实验对一种新型无柄解剖形人工髋关节 (英文名称为 A- Fix TM :Non- stem med Anatomical Total HipProsthesis)仿真临床置换术下的早期 (无骨水泥固定 )和后期 (用骨水泥固定模拟骨组织自然生长 )状态 ,进行生物力学实验研究 ,并对照正常自然股骨和股骨颈对实验结果进行归一化系数分析比较 .结果显示 ,无柄人工髋置换术后无骨水泥固定态和骨水泥固定态的股骨头垂直位移相似 ,均略大于正常股骨态的位移。置换后无骨水泥固定态和骨水泥固定态的应变分布特征也相同 ,但与正常态相比 ,股骨颈的受拉侧和受压侧的应变值都明显降低 ,并且变化平缓。相对于正常态而言 ,置换后无骨水泥固定态的安全系数在受拉侧提高 13% ,受压侧提高 2 7.6 % ;置换后骨水泥固定态的安全系数在受拉侧提高 2 9.6 % ,受压侧提高 2 2 .1%。置换前后股骨头最大扭转角都小于 0 .3°,无骨水泥固定态的扭转角是正常态的 0 .0 2倍 ,骨水泥固定态的扭转角是正常态的 0 .0 1倍。研究表明新型无柄解剖形人工髋关节具有低应力 ,高强度和小变形 ,抗松动 ,高刚度等一系列优异的力学特性 ,为其临床应用和推广 ,提供可靠的力学依据。

Biomechanical Experiment of Non-stemmed Anatomical Total Hip Prosthesis Arthroplasty in Vitro

Biomechanical test in vitro was performed to study the biomechanical characteristics of the femoral component in the non-stemmed anatomical total hip prosthesis (A-Fix TM) arthroplasty. It mimics two stages, the early stage with cementless and the later stage with cement fixation that imitates bone ingrowth. The results were compared with that of normal proximal femur by normalized coefficient analysis. Translation of femoral head after hip replacement is slightly more than normal. The strain of femoral neck after replacement is lower than that of normal. It changes flatly. The security coefficient in early stage is raised by 13% on the tensile side and by 27.6% on the compressive side of femoral neck; that in later stage is raised by 29.6% and by 22.1% separately. The maximal torsional angle of femoral head is minimal, it is 0.02 times that of normal in early stage and 0.01 times in later stage. It demonstrated that A-Fix TM arthroplasty has the characteristics of low stress and deformation, high intensity and rigidity, and anti-loosening, thus affording mechanical evidences for its clinical use.