A backstop structure of a dynamic hip screw (DHS) is disclosed. The dynamic hip screw comprises a tension bolt, a side fixing plate, a sleeve and a pressing bolt. The backstop structure, which is attached to the side fixing plate, comprises a stop part that is located relative to a lower-level aperture of the sleeve. The height of the highest point of the stop part at the lower-level aperture of the sleeve is inversely proportional to the backward slip distance of the tension bolt and the pressing bolt from an insertion position toward the lower-level aperture of the sleeve within the sleeve. The more the height of the highest point of the stop part at the lower-level aperture of the sleeve is, the less the backward slip distance.一種股骨動態固定器(Dynamic Hip Screw,DHS)之後擋結構,該股骨動態固定器包括一拉力螺釘、一側固定板、一套筒以及一加壓螺釘;該後擋結構附加於該側固定板上,該後擋結構的擋止部相對於該套筒的低位孔口,該擋止部的最高點在該低位孔口中的高度,與允許該拉力螺釘以及該加壓螺釘在該套筒中從一植入位置向該低位孔口方向滑退的距離成反比;該擋止部的最高點在該低位孔口中的高度愈高,該滑退的距離愈小。1‧‧‧拉力螺釘2‧‧‧側固定板200‧‧‧固定孔201‧‧‧容置槽202‧‧‧連通部203‧‧‧凸出部3‧‧‧套筒4‧‧‧加壓螺釘401‧‧‧釘頭402‧‧‧端面6‧‧‧高位孔口7‧‧‧低位孔口8‧‧‧後擋結構10‧‧‧擋塊11‧‧‧擋止部30‧‧‧定位件
