DESIGN OPTIMIZATION FOR DYNAMIC HIP SCREW FIXATION IN PROXIMAL FEMUR INTERTROCHANTER FRACTURE

INTRODUCTION Surgery is treatment of choice for intertrochanteric hip fracture. As a golden standard, stable fractures should be treated with DHS system, and it had bee followed for decades. The successful rate of DHS systems is excellent in stable fractures with few complications and the technique is simple. In the hence, DHS systems in treating stable intertrochanter hip fractures dominates all over the world. As minimal invasion surgery prevailing today, however, the traditional DHS systems used in operation with a long four-holed side plate, which made the surgical incision longer than other hip surgical procedures. DHS systems with two holed side plate appeared several years ago and had been applied clinically with good results. Clinical and biomechanical researches revealed that DHS systems with two holed side plate could reach the result as the one of four holed side plate, but with smaller incision, shorter operation time and less blood loss during and after operation. In this study we simulated simple trochanteric fracture model using two holed and four holed DHS systems under one reference load (stance phase of the gait cycle). Several different situations were analysed by finite elements, and we would discuss the optimized design for screw position in two holed DHS systems that could get maximum fixation.