A comparison of two methods for inserting lag screws.

This study compared the accuracy of two accepted methods of inserting lag screws. The ability of the two techniques to produce concentrically drilled holes between the inner and outer cortices, the ability to accurately overdrill a small hole, and the displacement of the cortices following application and tightening of the lag screw were investigated using an experimental model of bony cortices. The results indicate that when the gap between the cortices is large, both methods of lag screw insertion are equally inaccurate. For smaller gaps between the cortices, the drill guide technique is more accurate than the other.