removing plaster casts

[richardb]

My arm is in plaster following a skiing accident. I am told that when the plaster is ready to be removed, the hospital might use an electric saw which cuts through the plaster but which will not cut into skin. How does this work?

[Andy]

The saw uses a semi-circular blade, best described as the bottom half of a circle, which oscillates back and forth at high speed by a minute amount. As the plaster cast is hard, the saw will cut through it, but as skin is soft and flexible, the amount of movement is insufficient to cut it and the skin will move with the blade without injury. the blade is set to a depth which will only just get through the plaster and barely touch the skin.