Augat Peter, Rapp Stefan, Claes Lutz
Institute of Orthopaedic Research and Biomechanics, University of Ulm, Helmholtzstrasse 14, 89081 Ulm, Germany.
J Orthop Trauma. 2002 May;16(5):311-6. doi: 10.1097/00005131-200205000-00004.
To evaluate a modified sliding hip screw for the fixation of trochanteric fractures that provides increased fixation strength in osteoporotic bones and allows for the safe intraoperative application of bone cement.
Biomechanical cadaver study.
Unstable trochanteric fractures were simulated by osteotomy in nine pairs of cadaveric femurs and stabilized by a standard sliding hip screw randomly assigned to the left or right femur. The contralateral femur was stabilized with a newly designed hip screw, which was augmented with low-viscosity bone cement.
Femoral bone mineral density was measured by dual x-ray absorptiometry and quantitative computed tomography. Fixation stability of the hip was assessed after dynamic loading by displacement measurement of the femoral head in a simulated one-leg stance configuration.
Modification of the hip screw together with cement augmentation significantly (p < 0.05) increased the initial stability of the fracture fixation technique. The total displacement of the femoral head was reduced by 39 percent on average using cement augmentation in the modified screw compared with the standard sliding hip screw. The largest improvement in initial fixation stability was found for the most osteoporotic bones.
This modified hip screw augmented with bone cement can significantly enhance the initial fixation stability of trochanteric fractures in osteoporotic femurs.
评估一种改良型滑动髋螺钉用于转子间骨折固定，该螺钉可增强骨质疏松性骨的固定强度，并允许在术中安全应用骨水泥。
生物力学尸体研究。
通过在九对尸体股骨上进行截骨术模拟不稳定转子间骨折，并用随机分配至左侧或右侧股骨的标准滑动髋螺钉进行固定。对侧股骨用新设计的髋螺钉固定，并用低粘度骨水泥增强。
通过双能X线吸收法和定量计算机断层扫描测量股骨骨密度。在动态加载后，通过模拟单腿站立姿势下股骨头的位移测量来评估髋关节的固定稳定性。
髋螺钉的改良与骨水泥增强显著（p < 0.05）提高了骨折固定技术的初始稳定性。与标准滑动髋螺钉相比，在改良螺钉中使用骨水泥增强后，股骨头的总位移平均减少了39%。在骨质疏松最严重的骨中，初始固定稳定性改善最大。
这种用骨水泥增强的改良髋螺钉可显著提高骨质疏松性股骨转子间骨折的初始固定稳定性。
