[Design and manufacture of the static 3 dimensional screw-plate system and its matching tools]

To design and manufacture a new type instrument and its matching tools for the proximal femur.A new type instrument of subtrochanterical fracture-static 3-dimensional screw-plate system(STDSP)was designed and manufactured. The different types of accessory instruments which adapted to STDSP,the aiming guide, and the accessory tools were also designed and manufactured, and they were tested on bones.STDSP included 3 special lag screws and 1 anatomic plate. The lag screws distributed in femoral neck like "or"shape. There was 135 degree between the lag screws and femoral shaft. The shape of the plate was similar to the anatomic structure of the proximal thighbone. The posterior screw was stably connected to the plate. The plate was affixed crosswise to the lateral and anterior side by bicortical screws. The aiming guides and all kinds of accessory tools could help to install STDSP exactly and conveniently,which was verified on cadavers and X-ray photographs.STDSP has the function of dynamic compressing in 3-dimensional space, and can match with the structure of the proximal femur preferably. STDSP may be a suitable instrument to the subtrochanteric fractures. The accessory apparatus of STDSP has simple configuration,and can let the STDSP be installed accurately, conveniently and rapidly.