Keeping osteocytes alive: a comparison of drilling and hammering k-wires into bone.

In this study, the insertion time and histological effects of drilling and hammering K-wires into bone are described. The insertion time was measured while drilling or hammering K-wires into the femurs and tibias of ten rabbits. Four K-wires, inserted into one hind limb, were used for histological examination directly after insertion and four K-wires inserted into the contralateral hind limb were used for the same measurements 4 weeks later. The specimens were scored for presence, or absence, of osteocytes, fragmentation of the bone edges, haemorrhage, microfractures, cortical reaction and callus formation around the pin track. The insertion time needed for drilling in K-wires was significantly longer than that of hammering. Drilling also resulted in the disappearance of the osteocytes in almost all sections while hammering did not have this effect but did result in more microfractures. Hammering K-wires may be a superior technique because it prevents osteonecrosis and requires a shorter insertion time.