Dynamic Hip Screw

Dynamic hip screws are used for internal fixation of fractures of the femoral neck and intertrochanteric region. The screw is a large cancellous lag screw that glide freely in a metal sleeve. The sleeve is attached to a side plate that is fixed to the lateral femoral cortex with screws. Weight bearing cause the femoral head to becomes impacted on the femoral neck producing dynamic compression of the fracture. The shaft of the lag screw slides down the sleeve maintaining reduction of the fracture as compression occurs.


Assembled dynamic hip screw. The lag screw for the femoral head is within in sleeve of the side plate. The side plate shows the fixation screws that are inserted into the femoral diaphysis. The two upper screws are cancellous screws and lower four screws are cortical screws. Dynamic hip screw transfixing an intertrochanteric fracture of the right femur. A cannulated cancellous screw that serves as a lag screw has also been inserted to increase compression and to control rotation of the femoral head. Note the lesser trochanter has been fractured off the femur and has been displaced medially.