The Evaluation Of The Biomechanical Stability Of CPC And DHS System In Fixation In The Intertrochanteric Fracture With Osteoporosis

Intertrochanteric fracture occurs at the point between the base of femoral neck and smaller trochanter. Because it always occurs in elderly patients who always have osteoporosis and may need special attention to other diseases, it is difficult to deal with in clinic. Non-union is almost impossible for good blood supply , but bed ulcer, bronchopneumonia and urol infection may happen, and original disease may get serious after deep vein emblosis a long time of bed-lying, hip vuras , short and external rotational deformity may form after the union of bone, while morbility in open reduction and internal fixation is only about 13%,so many scholars oppoint surgery. DHS(Dynamic hip screw), angle plate and intramedullary nail are good choices for trochanteric fracture. DHS is choiced by many scholars for its better mechanical character, but it also has some complications, such as loosen of screw, erode of femoral head by screw. We test some biomechanical indexs of DHS in the treatment of type A1 intertrocharteric fracture which was enhanced by CPC, in order to find a new way to reduce the loosen of DHS. [Objective] To evaluate the biomechanical stability of CPC and DHS system in fixation in the intertrochanteric A1 fracture. [Methods] 12 fresh old men's femoral specimens which were made into intertrochanteric A1 fractures were divided into two groups randomly (A, B). Group A was fixed by CPC and DHS system, group B by simple DHS system. Methods were compared through experimental stress analysis on CSS-10. [Result] The axis compress displacement of CPC and DHS system and simple DHS system were (0.92±0.03)mm ,(1.91±0.05)mm, respectively when compress rich 600N . Torsion angels were (1.40 ±0.03) °,(2.29 ±0.11) °respectively .There were significant differences among these two different fixation methods (P<0.05). The greatest axial pullout strength of A group was 3625N ,B group was 2380N , There were significant differences between A and B (P<0.05). In this experiment, CPC enhanced DHS not only keep the property of DHS, but also improves its stability,...