Principles of stable internal fixation.

The results of internal fixation can be adversely affected by implant failure before union takes place. The survival of an internal fixation device depends upon load transfer from fragment to fragment. Techniques that do not provide such a load sharing between implant and bone will lead to failure of the implant. For example, absence of contact between cortices opposite the plate will increase the forces acting on the device which will either pull out, shear or break. This review focuses on the methods of applying implant to bone to achieve stable fixation and thus restore early function without sacrificing reduction and union.