The effect of screw holes on bone strength

Internal fixation devices continue to be used in the fixation of foot and ankle fractures and osteotomies. Because of the increased use of fixation techniques, postoperative care following removal of internal fixation devices assumes a vital role in the success of these procedures. Using 10 fibulas from 5 cadavers, the authors tested the resistance of 5 intact fibulas and 5 contralateral fibulas with one 3.5-mm. drill hole to bending forces. The mean load at failure of the intact fibulas was 360.86 N (range 181.69-800.14 N), whereas the mean load at failure of the drilled fibulas was 215.20 N (range 66.49-600.61 N). The drilled fibulas displayed failure with the application of 59.63% of the mean load applied to the intact fibulas at failure (p = 0.007).