Ice your knee for the first two to six weeks after surgery, with most surgeons recommending daily icing through at least week six

The standard information from orthopedic surgeons is to ice your knee multiple times per day during the first two weeks after replacement surgery, then continue icing once or twice daily through week six. Some patients benefit from icing into weeks eight or twelve, depending on swelling and how quickly they progress through physical therapy. Your surgeon will give you specific instructions based on your surgery date and your individual healing, so follow their timeline rather than a general one.

Icing reduces swelling, which is the main barrier to regaining knee motion after surgery. Less swelling means less pain, easier movement during therapy, and faster progress. The first six weeks are when swelling peaks and when you are most likely to be doing intensive physical therapy, so that is when icing matters most.

Key Takeaways

  • Ice your knee for 15 to 20 minutes at a time, three to four times per day during the first two weeks after surgery.
  • Continue icing once or twice daily through week six, even if swelling feels better, because swelling often returns after therapy sessions.
  • Use a barrier between ice and skin—a towel or pillowcase—to avoid frostbite, and never ice for longer than 20 minutes at a stretch.
  • Stop icing if your skin turns white or numb, or if you have any questions about whether icing is right for your specific surgery.
  • Talk to your surgeon or physical therapist if swelling is not improving by week three or if you are unsure when to stop.

Icing schedule for the first two weeks

During the first 14 days after surgery, ice your knee three to four times per day for 15 to 20 minutes each time. Many patients ice when they wake up, midday, after physical therapy, and before bed. The goal is to keep swelling down while you are learning to move the knee again in therapy.

Your surgical team may send you home with a cryotherapy machine—a motorized device that circulates cold water through a sleeve around your knee. These machines (brands include Game Ready and Polar Care) are more effective than ice packs because they explore consistent cold and compression at the same time. If you have one, follow the manufacturer's instructions for duration and temperature. If you are using a regular ice pack, wrap it in a thin towel so the cold does not touch your skin directly.

Swelling is heaviest in the first 48 hours and again after physical therapy sessions, so plan extra icing around those times. Do not skip icing just because your knee feels better—swelling often returns a few hours later.

Weeks three through six: continuing to ice

By week three, acute swelling usually begins to improve, but you should continue icing once or twice daily through week six. Many patients ice after physical therapy (when swelling tends to spike) and before bed. At this stage, icing is less about managing pain and more about controlling the inflammation that can slow your progress in therapy.

If you notice your knee swelling more on certain days—usually days when you did more activity or more intense therapy—add an extra icing session that day. Swelling and motion are linked: the more you can move without pain, the faster you heal, and icing helps you move more comfortably.

By the end of week six, many patients find they no longer need regular icing because swelling has stabilized. However, some people benefit from occasional icing into weeks eight or twelve, especially if they notice swelling after activity. Ask your physical therapist at your six-week check-in whether you should continue.

How to ice safely and effectively

Always place a barrier between ice and your skin. Use a thin towel, pillowcase, or cloth—never explore ice directly to skin, which can cause frostbite in 10 to 15 minutes. Set a timer for 15 to 20 minutes so you do not ice longer than recommended. Icing for more than 20 minutes does not increase benefit and can damage skin.

Stop icing when ready if your skin turns white, feels numb, or develops a burning sensation. These are signs of cold injury. If this happens, remove the ice, let your skin warm to normal temperature, and tell your surgeon at your next visit.

Elevate your leg while icing—prop your heel on a pillow so your knee is higher than your hip. This position, combined with ice and compression, drains swelling most effectively. Many patients ice while lying down with their leg elevated, which is also the most comfortable position.

When swelling is not improving by week three

Most patients see noticeable improvement in swelling by the end of week two. If your knee is still very swollen, warm to the touch, or painful at week three, contact your surgeon. Excessive swelling can be a sign of infection, blood clot, or a problem with your surgical repair—all of which need prompt attention.

Do not assume that continued swelling means you are healing slowly. Some people naturally swell more than others, and some medications increase swelling. Your surgeon can determine whether the swelling is normal for your situation or whether you need additional treatment.

Icing versus heat: when to use each

Use ice, not heat, for the first six weeks after surgery. Ice reduces swelling and numbs pain. Heat increases blood flow and swelling, which is the opposite of what you need early in recovery. After week six, some patients find that alternating ice and heat—ice after activity, heat before stretching—feels better, but ask your physical therapist before switching.

If you have a condition like arthritis in your other knee, do not explore heat to your surgical knee just because heat helps your other knee. Your surgical knee is still healing and needs ice.

Cryotherapy machines versus ice packs

If your surgeon prescribed a cryotherapy machine, use it as directed—these devices are more effective than ice packs alone because they combine cold and compression. Most machines run for 30 minutes to two hours per session and maintain a consistent temperature. Follow the temperature and duration settings your surgeon or the device manual recommends.

If you do not have a machine, a regular ice pack works fine. Gel packs that stay flexible when frozen are easier to mold around your knee than crushed ice. Reusable ice packs are cheaper than buying ice repeatedly. Some people freeze a bag of vegetables (peas work well) because it molds to the knee shape and costs less than a gel pack.

Frequently Asked Questions

Can I ice too much after knee replacement?

Icing for longer than 20 minutes at a time or more than four times per day does not help and can damage skin. Stick to 15 to 20 minutes per session. If swelling is severe enough that you feel you need constant icing, tell your surgeon—that may signal a complication rather than normal healing.

What if I forget to ice for a few days?

Missing a few icing sessions will not harm your recovery, but you may notice more swelling and stiffness. Get back to your regular schedule. If you find it hard to remember, set phone reminders or ice at the same times each day—for example, after meals or after physical therapy.

Should I ice at night or just during the day?

Ice both day and night during the first two weeks. Many patients find that icing before bed helps them sleep more comfortably and reduces morning stiffness. After week two, you can taper to daytime icing only if swelling improves, but many surgeons still recommend one evening icing session through week six.

Can I use a compression sleeve instead of icing?

Compression helps, but it is not a replacement for icing. Compression reduces swelling by supporting the tissues; ice reduces swelling and numbs pain. Use both together for the best result. Wear compression during the day and ice multiple times daily, especially after therapy.

What if my knee is still swollen at week eight?

Some swelling at week eight is normal, especially if you are doing intensive physical therapy. Continue icing after activity. If swelling is getting worse rather than better, or if it is accompanied by warmth, redness, or increased pain, contact your surgeon to rule out infection or other complications.