The principle of applying dynamic compression depends on relative movement between the bone and the plate as the screw is tightened.
Insertion of screw in compression mode for transverse fracture (application of compression plate)
Insertion of screw in compression mode for oblique fracture (application of compression plate)
For one-third tubular plates the universal spring-loaded DCP drill guide is used without pressing it against the bone. The guide is placed against the edge of the plate hole, distal to the fracture.
For LC-DCP plates, the DCP drill guide with a gold collar is used. The arrow should point in the direction of the fracture.
In LCP combi holes, the universal spring-loaded DCP drill guide without pressure against the bone can be used in the non-threaded portion of the hole.
The hole is drilled through both cortices.
A depth gauge is used to determine the screw length.
If self-tapping screws are used add 2 mm to the screw length so that the portion of the screw in the far cortex is fully threaded.
The hole is tapped.
If self-tapping screws are used, this step can be omitted.
As the screw is tightened, the head displaces in relation to the plate, moving the bone sideways with it in relation to the plate.
After the screw has been tightened, the fracture gap should have closed and now be compressed.