These instruments are intended to cover the entire field of bone surgery and to do it in such a manner that, from the standpoint of antisepsis, they need cause no more anxiety than would ordinary hand instruments.
There is a set of these instruments, consisting of two cross cut saws (or reciprocators), an automatic chisel and a drill, or rotator; also several attachments and many tips, such as saw blades, drills and chisel blades. These instruments are driven through a flexible shaft and by means of a Universal Motor permanently housed in a carrying case.
With these instruments any kind of sawing imaginable can be done, and done without danger, because the hand can be closed on the teeth of the saw when it is going at full speed and yet with no danger to the hand. That is why ribs may be severed without injuring the pleura, or bone flaps made in the