The bone fragment of an oblique fracture is inclined to slip over each other. The bone plate should be applied to function as a compression plate and buttress plate.
If a plate is immobile to the fragment which forms an acute angle with the fracture. Then axial compression is generated because of which fragment is displaced and the reduction is lost.
On the other hand, if the plate is immobile to the fragment which forms an obtuse angle along with the fracture. Then axial compression is generated, and spike of the conflicting fragment is driven against the plate. accordingly, displacement is prevented, and axial compression is achieved.
Double Plating –
Usually double plating of the bone is not required. It is exceptional when bone quality is less than the optimal. Also, double plating may be called in a fracture configuration where solid bone contact on the cortex opposite the plate is improbable. Always second plate should be smaller both in length and size, then the major fixation plate as two plate of a similar length act as severe stress riser at their ends. Generally, double plating is used to fixed subtrochanteric and supracondylar fracture of the femur.