The effect of drill hole location on load bearing capacity of long bones.

We investigated how load bearing capacity (LBC) of long bone differs with a bicortical drill hole in a compressive/tensile location vs. a neutral location. Group I had a hole drilled through 0°/180° ([compressive at 0°/maximum tensile at 180°]), Group II at 90°/270° ([neutral]), and Group III at 135°/315° ([tensile at 135°/compressive at 315°]). Maximum load at failure and stiffness was measured. A significant ([p < 0.05]) decrease in LBC of all Group I and Group III bones was observed. Loss of strength for Group II was statistically insignificant ([p > 0.05]). Changes in stiffness for both tibias and fibulas was not statistically significant ([p > 0.05]).