Lenich A, Fierlbeck J, Al-Munajjed A, Dendorfer S, Mai R, Füchtmeier B, Mayr E, Hammer J
Department of Trauma- and Reconstructive Surgery, Klinikum Augsburg, Augsburg, Germany.
Technol Health Care. 2006;14(4-5):403-9.
Conventional osteosynthesis of proximal femur fractures is still affected by serious complication rates between 4-18%, even though advanced implant modifications and surgical techniques are common practice. In terms of increasing age and co-morbidity of patients this complication ratio is expected to increase even further in the immediate future. One major reason for implant failure is the decreasing stability potential of the implant due to a loss in mechanical properties of cancellous bone. Therefore, efforts in new intramedulary techniques specifically focus on the load bearing characteristics of the implant by developing new geometries to improve the implant-tissue interface. This investigation discusses first clinical results of the trochanteric fixation nail TFN (145 patients) and a biomechanical analysis of the blade/femur head interaction under different static loading conditions. The TFN shows promising performance in first clinical results. In the clinical study the overall complication rate was significantly lower compared to other similar osteosynthesis. For the investigation of the biomechanical stability of the helical TFN blade the following experiments were performed: Analysis of the axial load required for insertion of the blade by free rotation; measurement of the corresponding rotation angle for total insertion (32 mm) (n = 8); pull-out forces with suppressed rotation (n = 4); loads for rotational overwinding of the implant in the fully inserted condition (n = 4). All investigations were performed on human femoral heads. The bone mineral densities of the specimens were detected by QCT-scans. Prior to cadaveric testing the experimental set-up was validated (n = 8) by the use of synthetic foam blocks (Sawbone).
尽管先进的植入物改进和手术技术已成为常规操作，但股骨近端骨折的传统骨固定术仍受到4%至18%的严重并发症发生率的影响。鉴于患者年龄增长和合并症情况，预计在不久的将来，这一并发症比率还会进一步上升。植入物失败的一个主要原因是由于松质骨机械性能丧失，植入物的稳定性潜力下降。因此，新的髓内技术的努力特别集中在通过开发新的几何形状来改善植入物 - 组织界面，从而关注植入物的承重特性。本研究讨论了转子间固定钉TFN（145例患者）的首次临床结果以及在不同静态加载条件下刀片/股骨头相互作用的生物力学分析。TFN在首次临床结果中显示出良好的性能。在临床研究中，与其他类似的骨固定术相比，总体并发症发生率显著更低。为了研究螺旋TFN刀片的生物力学稳定性，进行了以下实验：通过自由旋转分析刀片插入所需的轴向载荷；测量完全插入（32毫米）时的相应旋转角度（n = 8）；抑制旋转时的拔出力（n = 4）；在完全插入状态下植入物旋转过绕的载荷（n = 4）。所有研究均在人体股骨头上进行。通过QCT扫描检测标本的骨矿物质密度。在尸体测试之前，通过使用合成泡沫块（Sawbone）对实验装置进行了验证（n = 8）。
