Orthopaedic Biomechanics Made Easy

Introduction to fracture fixation

The principles of fracture fixation are as follows:

Reduce the fracture

This can be achieved by: indirect method (i.e. closed reduction), which does not require exposure of the fracture; or direct method (i.e. open reduction), which involves formal exposure of the fracture. A fracture can also be reduced by a percutaneous method, which involves a limited direct access to the fracture to aid closed reduction.

Intra-articular fractures ideally require ‘anatomic’ reduction, to restore the articular surface. In contrast, extraarticular fractures usually only require ‘adequate’ (i.e. non-anatomical) reduction, as the goal is to restore the length, rotation and alignment of the bone, which usually does not require perfect reduction of the fracture.

Hold the fracture reduced until it is united

This can be achieved by external fixation or by internal fixation methods. The fracture does not heal any quicker whether treated by one method or the other. However, different fixation methods have different mechanisms for maintaining fracture reduction; some methods permit closed/adequate reduction, whilst other methods enable open/anatomic reduction. A fixation device is redundant once the fracture has healed.

Rehabilitation

This helps to reduce tissue oedema, preserve joint motion, improve muscle power and restore normal function of the limb. Internal fixation provides immediate skeletal stability and generally permits early rehabilitation and return to function.