Arthroscopic ankle fusion-Drilling
For a 6.5 mm screw the 5mm drill is used. The 5.5 mm drill for the 8.0mm screw .Drilling is under image intensification. If the bone is soft it may be that the 6.5mm screw will not provide sound enough fixation for the arthroscopic ankle fusion .Further drilling is generally not required, simply upsize to an 8.0mm screw.