No. Do not use donut-shaped or ring-shaped cushions. They reduce blood flow to the area, which may cause sores.
That’s worth thinking about, because the logic of a ring cushion is so convincing. A hole where the sore is seems as though it should take the pressure off the sore. And it does lift pressure off the middle. The problem is what the ring does to the blood supply of the tissue it presses on, and the result can be sores rather than relief.
Ring cushions are also widely sold, often marketed for exactly this purpose. This is one of the few places where the medical advice goes against what’s on the shelf.
What to use instead is a type of support rather than a specific product: use pillows, foam cushions, booties, or mattress pads to reduce the pressure. Some pads are water- or air-filled to help support and cushion the area.
It can’t be narrowed down further here, for a good reason. The type of cushion you use depends on your wound and whether you are in bed or in a wheelchair. Talk with your health care provider about what choices would be best for you, including what shapes and types of material.
A cushion is also only half of pressure relief. The other half is movement: about every 2 hours in bed, and every 15 minutes in a wheelchair.