A cast is often used for treatment of a broken bone, post-surgical recovery, and for other ailments that require immobilization. Casts are made of one of two materials: plaster or fiberglass. Once it is time for the cast to come off, a cast saw is used to remove the cast. Learn about how a cast saw works, how safe it is, and what you can do to make this a less frightening experience.
How It Works
Cast saws have a sharp, small-toothed blade that rapidly vibrates back and forth; it does not spin around like a circular saw. Against the firm surface of the plaster or fiberglass, the cast saw will cut through the material. However, against your skin, the cast saw simply moves the skin back and forth with the vibration, not cutting into the skin.
Is It Safe?
Cast saws are very safe, but they should only be used by personnel who have been trained in their proper use and how to avoid problems. Improper use of a cast saw, or use of a cast saw that has worn blades, can cause problems. Cast saws are safe, but there are possible complications of their use that can occur. Many people tell stories of being cut or burned by a cast saw, but with proper use, these injuries should not occur.
What Can Go Wrong?
There are a few problems that can occur with the use of a cast saw, and it is important that the device is used by someone knowledgeable with proper cast saw techniques. While a physician should know proper cast saw techniques, many cast techs, physician assistants, and medical assistants are also qualified in using this device.
A recent study found that the most common reasons patients had complications from the use of a cast saw were worn out blades, insufficient cast padding, or improper training and experience. The rate of injury from a cast saw is right around 1%, therefore the risk is small, but not nonexistent. The most common problems include:
- Burns: Skin burns are the most common problem that occur when removing a cast. Because of the vibration of the cast saw blade, high temperatures can result from the friction of the blade against the cast material. If the blade heats up and contacts the skin, a burn can occur. Lighter pressures to prevent heating of the blade, and allowing a warm blade to cool, can help prevent this problem. Skin temperatures have been shown to be higher when cutting through fiberglass cast material.
- Cuts: Small skin lacerations are uncommon, but can occur. The teeth of the saw blade can be sharp enough to cut the skin. If ample padding is under the hard cast material, a skin laceration is unlikely.
Making It Easier
Many patients, especially younger children, are frightened of cast saws, but there are some things that can be done to make the experience less traumatic.
- Explain to kids what is happening. Don't let the doctor or tech rush in and start removing the cast without showing the patient the equipment and how it works. Fear of the unknown is usually much worse than the fear of the saw.
- Show the patient that the saw will not cut the skin. Skin lacerations are the most common fear, and demonstrating that the saw will not cut your skin can help. I always press the blade of the running cast saw against my hand to demonstrate that it's safe.
- Bring headphones. A cast saw can be noisy, and often the noise is more upsetting than the actual feeling of the saw. Ear muffs, headphones, or a noise-cancelling device can help.
Even with these steps, some patients are still upset and frightened. Taking time, and addressing the patient's concerns can help. Unfortunately, some kids are too young to understand, and that's where a promise of an ice cream treat may be the only thing that helps get you through!
Shuler FD and Grisafi FN. "Cast-saw burns: evaluation of skin, cast, and blade temperatures generated during cast removal" J Bone Joint Surg Am. 2008 Dec;90(12):2626-30.
Shore BJ, et al. "Epidemiology and Prevention of Cast Saw Injuries: Results of a Quality Improvement Program at a Single Institution" J Bone Joint Surg Am, 2014 Feb 19;96(4):e31 1-8.