dynamic hip screw
Dynamic hip screws (DHS) are a femoral head-sparing orthopedic device used to treat femoral neck fractures. It is sometimes referred to as a pin and plate.
Neck fractures that are undisplaced and hence have a low risk of avascular necrosis (Garden I and II fractures) can be treated with head-preserving surgery and internal fixation. If there is a high risk of femoral head avascular necrosis (Garden III and VI fractures), femoral head resection and hip hemiarthroplasty is preferred .
Following reduction, the fracture is internally fixed by applying a large lag screw through the neck, which is held laterally by a lateral femoral plate. The lag screw can slide in the plate along the longitudinal axis of the femoral neck, allowing compression of the fracture which aids healing. If sliding has taken place, the lateral end of the lag screw may protrude laterally from the plate.
Some surgeons will also insert a derotation screw into the neck (usually superior to the lag screw) to limit rotation which can cause non-union.
- non-union or malunion
- implant complication, e.g. screw or plate fracture (2% )
- avascular necrosis