Fixation Of The Fracture

Fixation of the fracture is the responsibility of the orthopaedic surgeon, but in choosing the method he has also to ensure that his choice does not conflict with the needs of the soft tissue injury. The essence of the method used is that it should provide rigid fixation of the fracture, and the potential alternatives are plaster of Paris, with or without a window, internal fixation using plate and screws, intramedullary nail fixation and external fixation frame.

 

With plaster of Paris fixation there is no access to the area of skin loss unless a large window is cut. A window of adequate size is likely to affect fixation of the fracture adversely, and on these grounds is undesirable. However, if a window is to be avoided, the skin cover used at the time of primary treatment has to be restricted to split skin grafting at the very most, and it is therefore not an option where skin damage is a significant part of the total injury.

Even without a window, plaster of Paris fixation alone may not be considered capable of providing the rigid fixation regarded as essential when the fracture
is unstable.
Internal fixation using plates and screws may be an effective method in the closed tibial fracture but in the compound fracture with skin loss its role is more open to question.

The site of skin loss nearly always overlies the subcutaneous surface of the tibia, and addition of the incisions and dissection required to expose the bone to insert an anteriorly applied plate extends the area of soft tissue damage to an undesirable degree, in the surface where the tibia is most vulnerable from the point of view of overlying skin necrosis. Application of the plate to the posterior surface is an alternative, but the posterior approach has not become standard practice in this context.

In the comminuted fracture particularly, the
method is unlikely to be the one of choice, and even in the absence of comminution it has the serious disadvantage of adding considerably to the amount of bone exposed and soft tissue dissected.
Intramedullary nail fixation might appear to have adverse factors.

It might well be felt that the exposure of the entire medullary cavity to the surface, which the insertion of such a nail entails, would invite the spread of infection from end to end of the bone. The fact that it is being successfully used, admittedly in conjunction with the provision of well-vascularised flap cover, would indicate that this fear is largely
groundless.

Viewed in relation to the provision of skin cover it has the considerable virtue that its use does not place any restraints on the method of providing skin cover selected by the plastic surgeon.
The external fixation frame also has the virtue of leaving the fracture site unimpeded from the point of view of providing skin cover.

 

The transfixion pins inserted into the bone at a distance from the fracture provide virtually absolute stability without interfering with the fracture site once the frame has been set up. The absence of interference with the soft tissues, damaged or undamaged, at or around the fracture site, allows the two components of the injury, bone and soft tissue, to be managed with minimal reference one to the other.

Almost the only aspect of the bony fixation which may affect soft tissue management is the site of insertion of the pins. This determines the line of the interconnecting bar, and thought should be given to this aspect to ensure that it does not make the reconstruction which the plastic surgeon wishes to use less easy technically, or even impossible. With this proviso, it leaves the entire range of reconstructive techniques available for use.