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2-23). Conventional plating is being increasingly replaced by using internal fixators (Fig. 2-24). These devices, like the PC-Fix, are splints which do not require being pressed “plate-like” to bone. Thus, the area of contact can be reduced to small points isolated from each other. When developing these implants it was realized, at the same time, that by fixing the screw heads within the plate of the PC-Fix, the length of the screws could be reduced to unicortical dimensions only. This allows safe use of self-drilling selftapping screws because the sharp drill bit tip of the screw no longer protrudes from the remote Fig.

After about 13 weeks, the callus healing has stabilized the fracture. Strain conditions will have to be taken into account when judging whether bony bridging or non-union will occur. The stage of remodeling may take from a few months to several years. 2 Complex multifragmentary fractures tolerate more motion between the fragments than simple ones. Much of the vascular supply to the callus area derives from the surrounding soft tissue. Stimulation of callus formation seems limited and may be insufficient if too large a fracture gap persists.

Buttressing is an important technique around the metaphyseal ends of the long bones. 2). 2-14). Radiologically, only minor changes can be observed: Under absolutely stable fixation, there is minimally visible callus formation or none at all. The fact that the fragment ends are closely apposed means that there is no actual fracture gap to be seen on the x-ray (Fig. 2-15). This renders the judgement of fracture healing difficult. A gradual disappearance of the fracture gap, with trabeculae growing across it, is a good sign, while a widening of the gap may be an indirect sign of instability.