Haynes R C, Pöll R G, Miles A W, Weston R B
School of Mechanical Engineering, University of Bath, UK.
Med Eng Phys. 1997 Jul;19(5):446-53. doi: 10.1016/s1350-4533(97)00003-9.
The sliding compression screw is widely regarded as the optimum treatment for intertrochanteric fractures of the femur, allowing bone fragments to impact until a bony support has been established across the fracture site. This study carried out biomechanical, cadaveric tests to establish the influence of direct static loading situations on the modes of failure of the Gamma Nail compared with the Dynamic Hip Screw (DHS). Clinical studies report DHS failures of lag screws cutting-out, bending of the lag screws and cortical screws pulling out causing plate loosening. Gamma Nail failures include lag screw cut-out or fractures of the femoral shaft around the distal locking screws or nail tip. In this study each failure mode has been isolated, to establish the loads to failure under various fracture configurations. The biomechanical results indicated that the intramedullary Gamma Locking Nail can be recommended over a standard DHS in cases of subtrochanteric fracture or conditions of very poor bone quality.
滑动加压螺钉被广泛认为是股骨转子间骨折的最佳治疗方法，它能使骨碎片相互嵌紧，直至在骨折部位形成骨支撑。本研究进行了生物力学尸体试验，以确定与动力髋螺钉（DHS）相比，直接静态加载情况对伽马钉失效模式的影响。临床研究报告了DHS的拉力螺钉穿出、拉力螺钉弯曲以及皮质螺钉拔出导致钢板松动等失效情况。伽马钉的失效包括拉力螺钉穿出或股骨远端锁定螺钉或钉尖周围的股骨干骨折。在本研究中，每种失效模式都已被分离出来，以确定在各种骨折构型下的失效载荷。生物力学结果表明，对于转子下骨折或骨质非常差的情况，髓内伽马锁定钉比标准DHS更值得推荐。
