Weeks 0 to 2: straighten first
You will be standing within a day and home in one to three. The knee is swollen, warm and stiff, and it will stay that way for longer than you expect. Two jobs matter in this fortnight: get the knee fully straight, and keep the swelling under control.
Targets
- Extension: the back of the knee flat on the bed. Rest with the heel on a rolled towel for 10 minutes, four to six times a day.
- Bend: toward 90 degrees by the end of week two. Heel slides, 10 repetitions every waking hour.
- Walking: two crutches or a frame. Short walks around the home every hour, then outside to the end of the road.
- Swelling: ice for 15 to 20 minutes, four times a day, with the leg raised above hip height.
Keep pillows out from under the knee. It feels kinder and it lets the joint stiffen in a bent position, which changes how you walk for good. Straight is the position that takes effort now and pays for years.
Weeks 2 to 6: build the bend
The wound is closed, the clips or stitches are out at around two weeks, and pain starts to ease. This is the window for range. Surgical teams look for about 90 degrees by week six, and a knee that is short of that gets discussed for a manipulation under anaesthetic.
Targets
- Bend: 90 degrees early in this phase, 110 by week six. Measure it weekly with a phone app so you see the trend.
- Walking: down to one crutch at around week three or four, none by week four to six. Hold it in the opposite hand.
- Strength: sit-to-stand from a dining chair, 3 sets of 10. Mini squats holding the worktop. Step-ups on the bottom stair.
- Bike: a static bike from week three or four. Start by rocking the pedals back and forth until a full turn comes.
- Stairs: one at a time, good leg up first, operated leg down first.
Weeks 6 to 12: get strong
Walking is comfortable enough that many people stop here. The operated leg is still far weaker than the other one, and that gap is what shows up as a limp at month six.
Targets
- Bend: 115 to 120 degrees, enough for stairs, a low sofa and a bicycle.
- Strength, three sessions a week: leg press, step-ups on to a full stair, sit-to-stand without hands from a lower seat, heel raises.
- Balance: stand on the operated leg for 30 seconds beside a worktop.
- Walking: 30 minutes without a stick by week 12.
- Stairs: alternate feet, up and down.
Months 3 to 12: finish the job
Most daily life is back by month three. Swelling and warmth after a busy day continue for three to six months, and for some people up to a year. Improvement carries on for the full twelve months when the strength work continues.
Cycling, swimming, golf, doubles tennis and long walks are all realistic. Kneeling stays uncomfortable for many people and is safe to practise on a cushion. Running and jumping sports are generally discouraged, so ask your surgeon about anything specific.
The dates people ask about
These are typical. Your surgeon sets the rules for your knee.
- Driving: around week six, once you can do an emergency stop. Tell your insurer.
- Desk work: weeks four to eight. Start with half days and get up every 30 minutes.
- Work on your feet: weeks 10 to 12 or later.
- The Tube and buses: from about week six for short trips outside rush hour. Use step-free stations and take a seat.
- Flying: short-haul from about six weeks and long-haul from about three months, after checking with your surgical team because of clot risk.
- Sleeping through the night: often the last thing to settle, at around weeks 8 to 12.
Stop and get seen if
- A calf that is swollen, hot and painful, or sudden breathlessness or chest pain. Call 999.
- A wound that is red, hot, leaking or opening, or a fever.
- Pain that is getting worse week on week after the first fortnight.
- A knee that suddenly gives way, locks or will not take weight.
- Bend stuck under 90 degrees at week six. Call your surgical team.
Straight answers
How long is the recovery from a knee replacement?
Most people are walking without aids by week six and back to normal daily life by month three. Strength and swelling keep improving until about month twelve.
What is the hardest week?
Weeks two and three for most people. The hospital pain relief has stepped down, sleep is poor and the bending work is at its most uncomfortable. It is also when the exercises matter most, so take your prescribed pain relief 30 to 40 minutes before each session.
How much should it bend by week six?
About 90 degrees as a minimum, with 110 a good result. If you are stuck below 90, tell your surgical team that week.
When does hands-on rehab help?
From around week two, once the wound is closed. Supervised rehab in the first three months gives better range and function than a sheet of home exercises alone. Lymphatic drainage helps with swelling, and soft tissue work eases the thigh and calf.