Patent ID: 9339311
Filing Date: 2016-05-17
CPC Classification: A61B

Claim Text:
1. A dynamic hip screw (DHS) with a rear-retaining structure, comprising: a dynamic hip screw, which comprises a lag screw, a sideplate, a sleeve, and a compression screw, wherein a rear-retaining structure, which comprises: wherein the positioning element is fixed in the fixation hole; the retaining block is mounted on an outer surface of the sideplate at a position adjacent to the lower orifice of the sleeve; the retaining block has a stopper portion opposite to the lower orifice, wherein the highest point of the stopper portion is located below the center of the lower orifice, and when the compression screw is at an initial implant position with a nail head thereof pushed up against the lower orifice, a gap exists between the highest point of the stopper portion and an end surface of the nail head of the compression screw to allow the lag screw and the compression screw to slip back in the sleeve from the initial implant position toward the lower orifice; and when the dynamic hip screw is fixed in a femoral neck fracture of a proximal femur, the higher the stopper portion is in the lower orifice, the smaller the distance that the lag screw and the compression screw are allowed to slip back in the sleeve from the initial implant position toward the lower orifice.