Best Way to Sleep After ACL Reconstruction
Ask anyone who has had an ACL reconstruction about the first week and sleep usually comes up before pain does. The knee throbs as soon as you lie down. You can’t find a position that feels safe. You wake at 3am, the ice pack has gone warm, and you’re not sure whether you’re allowed to bend the leg at all.
This is normal, and it does get better, usually faster than people expect. How you set yourself up at night makes a real difference in the meantime. Some of the details matter for more than comfort, too. Where you put the pillow, for example, can affect how well your knee straightens in the weeks ahead.
Why Are the First Few Nights So Difficult?
A few things work against you at once in the early days.
- The nerve block wears off. Many patients have a local anaesthetic block during surgery. It can keep the knee comfortable for the first several hours, then fade during the first night. Pain that seems to arrive out of nowhere at 2am is often just this.
- Swelling behaves differently when you lie down. During the day you’re up on crutches, moving about. At night the leg is still for hours, and a lot of patients notice more throbbing and tightness.
- You’re not used to lying still on your back. Most people naturally sleep on their side or front. Being told to stay on your back, with a leg propped up, is uncomfortable in its own right.
- There may be a second sore spot. With a hamstring graft, the back of the thigh can ache. With a patellar tendon graft, the front of the knee is tender and kneeling or pressure there hurts.
- Worry. Many patients lie awake afraid of damaging the graft by moving in their sleep. That fear is understandable, but a graft is fixed securely at the time of surgery and ordinary shifting in bed won’t pull it loose.
The Best Sleeping Position After ACL Reconstruction
For the first couple of weeks, the best position for most people is on your back, with the operated leg straight and raised on pillows. It keeps the knee still, lets swelling drain, and protects the one thing that matters most early on: getting the knee fully straight.
How to set up your pillows
Stack two or three pillows lengthways under your calf and heel so the whole lower leg is supported and the foot is higher than the knee. The back of the knee itself should have nothing under it. It should be able to sag gently towards straight. A foam leg wedge does the same job and doesn’t slide around during the night, which some patients find worth buying.
Why you shouldn’t put a pillow behind your knee
This is the single most common mistake, and it’s easy to see why people make it. A pillow tucked under a sore knee feels lovely. The knee relaxes into a slightly bent position and the ache eases.
The problem is that eight hours a night with the knee bent teaches it to stay bent. Losing full straightening (extension) is one of the complications surgeons work hardest to avoid after ACL reconstruction, because it’s much easier to prevent than to fix. A knee that won’t fully straighten causes a limp, puts extra load on the front of the joint and can hold back the whole rehab programme. Patient guidance from UCSF Health gives the same advice: pillows under the heel and calf, never behind the knee.
If your knee is already struggling to straighten, or you notice a clunk when it does, read our article on knee clicking after ACL reconstruction, which covers the cyclops lesion, one of the causes of lost extension.
What About Other Sleeping Positions?
Sleeping on your side
Side sleeping is possible once the early pain and swelling have settled. Lie on your good side, with a firm pillow between your knees so the operated leg doesn’t drop forward and twist. Many patients manage this within the first couple of weeks, but it varies a lot from person to person. We’ve covered this in detail in when you can sleep on your side after ACL surgery.
Sleeping on your front
Best avoided for the first few weeks. Lying face down puts pressure on the front of the knee, which is sore after a patellar tendon graft, and it’s hard to keep the leg from twisting as you turn over. Once the knee straightens fully and swelling has gone down, lying on your front for short periods is actually a common physio exercise for extension, but that’s done awake and on purpose, not all night.
Sleeping in a recliner
Some people sleep better in a reclining chair for the first few nights, especially if getting in and out of bed is a struggle. That’s fine, as long as the footrest supports the calf and heel and the knee isn’t left bent for hours. Tip the chair back far enough that the leg is raised and the knee can straighten.
Should You Sleep With Your Knee Brace On?
It depends on what your surgeon has asked for, and it’s worth being clear about this before you leave hospital. Many ACL reconstructions don’t need a brace at all. Where one is used, often because a meniscus was repaired at the same time, you may be asked to wear it at night for the first few weeks, usually locked straight. That protects the repair and holds the knee in extension while you sleep.
If you do sleep in a brace, check the straps haven’t tightened as swelling changes, and look at the skin underneath for red marks or pressure areas. Our guide to knee braces after ACL reconstruction explains when they’re used and why.
A Bedtime Routine That Helps
Ice before bed
Ice or a cold therapy device for around 20 minutes before you settle reduces the evening throbbing. Keep a thin cloth between the ice and your skin, and don’t fall asleep with an ice pack on, as it can burn the skin. If you have a cold therapy machine, follow the instructions you were given about how long to run it.
Time your pain relief
In the first week, regular pain relief works better than waiting until the pain builds. Many patients find it helps to take a dose as prescribed shortly before bed, so it’s working when they’re trying to fall asleep. Don’t add sleeping tablets or extra medication that hasn’t been prescribed, as some combine badly with post-operative painkillers.
Getting in and out of bed
Sit on the edge of the bed first. Then swing both legs in together, hooking your good foot under the ankle of the operated leg to lift it, or guiding it with your hands. To get out, reverse the process. Keep your crutches within reach of the bed, not across the room. Our article on how long you’ll use crutches after ACL reconstruction covers the early weeks on crutches.
Plan the night-time toilet trip
Falls in the first week tend to happen at night, half-asleep, on the way to the bathroom. Leave a lamp or night light on, clear the route of rugs and cables, and always use your crutches, even for a few steps. It sounds obvious. It’s also the advice patients most often ignore.
Keep moving during the day
Doing your physio exercises and the ankle pumps you were shown helps circulation and reduces stiffness, and a day of gentle activity makes it easier to sleep. Lying on the sofa all day and then trying to sleep all night rarely works well.
Does Sleep Actually Affect Your ACL Recovery?
There’s reasonable evidence that it does. A study of 89 athletes recovering from ACL reconstruction, published in Biology of Sport, found that those with better sleep quality during rehab were more likely to meet the criteria to be discharged back to sport. The link was strongest at around four and a half months after surgery. Lower insomnia and anxiety scores before rehab started were also linked with a better chance of getting there.
That doesn’t mean one bad week will set you back. It does mean that if sleep is still poor a month or two after surgery, it’s worth raising with your physio or surgeon rather than just putting up with it.
How Long Will Sleep Be Difficult?
Everyone is different, but this is the pattern most patients follow.
| Time after surgery | What’s typical |
|---|---|
| First 2 to 3 nights | The hardest stretch. Nerve block wears off, swelling peaks, back sleeping with the leg raised |
| Week 1 to 2 | Pain easing, fewer wake-ups. Still mostly on your back, perhaps trying the good side with a pillow between the knees |
| Week 2 to 4 | Many patients sleep on their side comfortably. Brace may still be needed at night if your surgeon asked for it |
| Week 4 to 6 onwards | Most people are back to their usual position. An occasional ache after a hard physio session is normal |
If you’re well behind this timeline, our article on why ACL recovery can take longer than expected may help.
When Is Night-Time Pain a Warning Sign?
Most bad nights are just part of healing. Contact your surgical team if you notice any of the following:
- Pain that is getting worse over several days rather than better
- A knee that is increasingly hot, red or swollen, or you have a temperature or feel shivery. See our guide to infection after ACL surgery
- Pain, tenderness or swelling in the calf, which can be a sign of a blood clot (DVT)
- Wound leakage that continues or changes colour
- Numbness or tingling in the foot that doesn’t settle once you change position or loosen the brace
Sudden breathlessness or chest pain after surgery needs emergency help. Call 999.
How Mr Webb Approaches Recovery at Night
Sleep is worth planning before you go home, because the first few nights are when most questions come up and there’s no one around at 3am to answer them. Mr Webb’s priorities at night are simple. Keep the knee straight. Stay on top of swelling and pain relief so you get enough rest to do your physio properly the next day. If sleep is still a problem a few weeks in, that’s usually a sign something needs adjusting, whether that’s pain relief, swelling control or the rehab plan itself.
If you’re considering ACL reconstruction, or you’re recovering from one and things don’t feel right, Mr Webb sees patients at his clinics in London and Surrey.
Frequently Asked Questions
Can I bend my knee in bed after ACL surgery?
Yes. Gentle bending as part of your exercises is encouraged. What you want to avoid is spending the whole night with the knee bent over a pillow. Moving the leg as you shift position in your sleep won’t damage the graft.
How many pillows should I use under my leg?
Usually two or three, placed under the calf and heel so your foot sits higher than your knee. Use enough to raise the leg comfortably, with nothing directly behind the knee.
Is it normal for my knee to hurt more at night?
Yes, especially in the first week. The leg is still for hours, you’re not distracted, and the nerve block from surgery often wears off during the first night. It should gradually ease. Pain that is getting worse rather than better should be checked.
When can I sleep normally after ACL reconstruction?
Most people are back to their usual sleeping position somewhere between two and six weeks after surgery. If you sleep on your front, that usually takes a little longer.
Can I sleep on my operated side?
Not in the early weeks. Lie on your good side with a pillow between the knees first. Lying on the operated side puts direct pressure on the wound and swollen tissues, so leave that until the knee is comfortable to the touch.
This article gives general information about sleeping after ACL reconstruction and is not a substitute for the advice your own surgical team gives you. If you’ve been given specific instructions about positioning or bracing, follow those.
Book a consultation with Mr Mark Webb at his London or Surrey clinics, or call +44 20 3824 2298.