| 摘要 |
A compression hip screw to aid in healing of a fracture between the neck and head of a femur includes a hollow lag screw having a threaded inner end adapted to be inserted through the neck and into the head of the femur to span the fracture therebetween, a spring assembly slidably disposed within the lag screw and attached thereto, a side plate having a barrel adapted to fit over the outer end of the lag screw and a shank section for mounting to the lateral aspect of the femur, and a compression screw insertable through the barrel and into threaded engagement with the spring assembly. The compression screw seats in a recess formed at one end of the barrel and is rotatable to move the spring assembly along its threaded shaft toward the side plate. In turn, the lag screw connected to the spring assembly is urged toward the side plate which forces the femoral head against the neck of the femur to apply a compression force at the fracture therebetween. The longitudinal axes of the compression screw and spring assembly are offset from the longitudinal axes of the lag screw and barrel, so that attempted rotation of the lag screw within the barrel causes the lag screw to follow an eccentric path and frictionally engage the interior wall of the barrel to prevent such rotation.
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