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When you’re having a cast removed, why doesn’t the machine cut your limb?

A GP explains why the machine stops short of a horror movie ending.

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Published: June 1, 2023 at 10:00 am

An orthopaedic cast is usually removed with a special cast saw, which is an oscillating power tool. Whileit might look like it could cause a lot of damage, a cast saw is designed with a sharp, small-toothed bladethatrapidly oscillates back and forth over a very small angle to cut material.

This is quite different to a normal circular saw, which has a rotating blade. A cast saw needs resistance to cut, and is specially designed to slice through rigid materials such as plaster. If it comes into contact with soft tissues such as skin, there is less resistance and so the saw will not cause injury.

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Asked by: Noel Walters, via email

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