Dynamic axial fixation. A rational alternative for the external fixation of fractures

Conventional external fixation systems neither inhibit motion at the fracture site sufficiently to permit primary bone healing, nor do they allow sufficient motion to encourage adequate external callus formation. Healing with such systems is therefore prolonged. These methods are usually reserved for the most severe fractures when internal fixation may be contraindicated. A unilateral, dynamic axial fixation system (Orthofix - registered trademark) is described which allows for simple conversion from a rigid to a dynamic mode, and so can be readily adapted to the changing physiological patterns of fracture repair. In 288 fresh fractures a success rate of 94% was achieved, with an average time to healing of 4.4 months. The incidence of pin-track infection was only 0.6%. The contribution which the mechanical and design features of the apparatus make to the results obtained is discussed. It is suggested that the system is capable of extending the range of indications for an externally mounted system to include many cases which would formerly have been treated by internal fixation, plaster cast or traction.