Ice treatment – or cold therapy as it’s also known – has been around for a very long time. Hippocrates recommended it for wounded soldiers in the 5th century BC. Later medics began to advocate for cold water treatments in the 1600s.
Ice therapy is one of those rare ancient regimens that has stood the test of time. In fact, if anything, there’s a growing push for patients to use it as part of their recoveries, post-surgery. But what is it actually doing within your knee? And how should you use it?
What does ice treatment do?
Surgery creates a wound. And our bodies react to wounds in a very specific way. It’s called the inflammatory response. Cells that have been damaged release chemicals into the wounded area, to attack bacteria and promote healing. These chemicals also prompt blood vessels to leak fluid into surrounding tissue, which causes swelling. Although inflammation is part of the healing process, it can also trigger pain.
This is where ice comes in. Ice is a vasoconstrictor, meaning it causes the blood vessels to narrow. The theory behind applying ice to the wound is that it 1) reduces tissue-bleed. Importantly, it can also:
- ease swelling
- reduce pain
How to ice your knee
Cold therapy is a widely-used treatment for surgical wounds. That said, you should first check with your surgeon or physiotherapist that it’s appropriate for you, and how and when they’d recommend you use it. But here’s some general advice for how to go about it:
Prepare your pack – Once you know your surgery date, you can add icepacks to your pre-hospital checklist of things to prep in advance. What you’re looking for is a surface that flexes around your knee joint. The usual recommendation is a pack of frozen peas. Peas are the right size and shape to create a bespoke ice wrap
…or make your own – There are various DIY methods for making icepacks too. One is to take a zip-closure freezer bag and add a small portion of crushed ice. Some people recommend adding a few tablespoons of rubbing alcohol to the mixture. This stops it from turning into a solid block
Use early – Because tissue damage is at its worst immediately after the wound has been created, ice treatment is most effective in the first stages of recovery – particularly 24-48 hours after your surgery
Layer up – When you’re ready to apply the pack, dampen a tea towel and wrap one or two layers of it around the pack. This will help to prevent it from freezing the skin and / or nerves and causing a cold burn (see below). We usually advise post-surgery patients to apply the ice over the bandage (rather than peeling it back for application)
Apply the pack – Hold the icepack against the target area of your knee – doctors generally advise against applying to much pressure as you do so. Ten to 20 minutes is usually enough, and we certainly wouldn’t recommend any longer than half an hour
Keep an eye on your skin – Exercise some caution as you’re icing your knee, to avoid the aforementioned risk of a cold burn. University Hospital Southampton’s post-knee replacement advice is to check your skin “every five minutes.” They add: “The skin should be pink. If the skin goes white, remove the bag until the pink flush is regained.”
Repeat the treatment – You can repeat the process several times during the day – three to four times is the general advice. Allow at least 30 minutes between treatments, if not longer. We normally suggest it’s worth continuing with ice treatment while the knee is swollen. That usually means the first 2-4 weeks, using it as required thereafter
Taking care with cold therapy
Bear in mind that ice treatment may not be suitable in certain situations and conditions. It shouldn’t be applied to broken skin or an open wound. It may not be appropriate if you have a circulatory or sensory problem. You should always remove the pack if your pain increases during icing. If you’re unsure about anything, check back with us or your GP for advice.