Dynamic Hip Screw


The Full form of DHS is Dynamic Hip Screw. DHS or Sliding Hip Screw fixation is designed for fixation of certain types of proximal femur or hip fractures. The screw is a large cancellous lag screw that can glide freely in a metal sleeve. The sleeve is attached to a plate which is fixed to the lateral femoral cortex with screws. Weight bearing thus causes the femoral neck to impact on the femoral metaphysis, producing dynamic fracture compression. This movement is only allowed in one plane along the sleeve, maintaining fracture reduction. As bone responds to dynamic stresses, this is intended to promote remodeling and fracture healing. The idea behind the dynamic compression is that the femoral head component is allowed to move along one plane; since bone responds to dynamic stresses, the native femur may undergo primary healing: cells join along boundaries, resulting in a robust joint requiring no remodeling. Hip fractures or Proximal femur can either be classified as extracapsular or intracapsular. Intracapsular fractures involve bone that is within the ligamentous hip joint capsule, and extracapsular fractures involve bone distal to the capsule. Extracapsular fractures of the proximal femur include intertrochanteric fractures (between the greater and lesser femoral trochanters), and subtrochanteric fractures (distal to the trochanters).