Structural changes in intact tubular bone after application of axial loads by external fixation

The effects of external fixation on bone structure were studied in the intact tibiofibular bone of the rabbit using three types of fixation; distractive, compressive and neutralizing. In the diaphyseal bone subperiosteal new bone formation was noted after three weeks in all fixation types. This formation was succeeded by endosteal resorption and porotic transformation of the cortical bone. An ultimate result was a widening of the medullary cavity. Torsion tests revealed weakening of the bone specimens as an end result. Axial loads, either compressive or distracting had no additional effect on the bone changes observed.