Knee arthritis (osteoarthritis) means the cartilage cushioning the knee joint has worn thinner, and the bone and tissues around it have changed. It causes pain, stiffness and swelling, especially after activity or first thing in the morning.
The treatments with the best evidence are EXERCISE and, if you carry extra weight, losing some of it. They’re recommended for everyone with knee arthritis, at every stage.
Knee arthritis doesn’t always get steadily worse. Many people have good years and bad patches. Knee replacement is for when the knee is limiting your life despite doing the basics well.
Symptoms
- Aching in the knee, worse after walking, stairs or standing a long time
- Stiffness first thing in the morning or after sitting, usually easing within half an hour
- Swelling that comes and goes
- Creaking or grinding
- The knee feeling weak or like it might give way
- Pain that flares for days or weeks, then settles
Pain mainly around or behind the kneecap, worse on stairs and squats, can also be runner’s knee, especially in younger, active people.
Your X-ray isn’t the whole story
- How bad the X-ray looks and how bad the knee feels often don’t match
- Some people with “severe” X-rays walk miles with little pain. Others with mild changes struggle
- Your pain, strength and what you can do matter more than the picture
- “Bone on bone” doesn’t mean exercise will damage it. Movement feeds cartilage and strengthens the muscles that protect the joint
An arthritic knee still needs loading. Strong thigh muscles are the knee’s best shock absorber.
What helps
- Strengthening: especially the thigh (quadriceps) and hip muscles. Sit-to-stands, step-ups, mini squats, leg presses. Two to three times a week, building up over 8 to 12 weeks
- Staying active: walking, cycling, swimming and water exercise. Some ache during activity is fine if it settles within a day
- Weight loss, if needed: each pound (about half a kilo) lost takes roughly four pounds of load off the knee with every step. Losing around 1 in 10 of your body weight can make a real difference to pain
- Pain relief: anti-inflammatory gels rubbed on the knee are a good first choice. Tablets can help in flares; ask your doctor what suits you
- A steroid injection: can calm a bad flare for a few weeks. It’s a short-term help, not a fix
- A walking stick in the OPPOSITE hand during flares, and supportive, cushioned shoes
What doesn’t help much
- Keyhole “clean-out” surgery (arthroscopy) for arthritis: did no better than exercise in trials. Guidelines strongly advise against it
- Gel injections (hyaluronic acid): major guidelines don’t recommend them routinely
- Glucosamine and chondroitin: little benefit in good-quality trials
- PRP injections: some small studies look promising, but a large trial found them no better than a placebo injection. Major guidelines don’t recommend them, and they’re often expensive
- Complete rest: weakens the muscles and makes the knee stiffer
When to think about knee replacement
- Pain is limiting your daily life, sleep or work despite a proper go at exercise, weight management and pain relief
- If only one part of the knee is worn, a partial replacement may be an option. See partial knee replacement
- Getting stronger before surgery helps recovery. How far your knee bends beforehand also predicts how far it bends afterward
- Recovery takes about a year. See knee replacement recovery week by week
Get it checked soon if
- The knee is hot, red and very swollen, especially with a fever
- It suddenly locks and won’t straighten
- You can’t put weight on it after a fall or twist
- Your calf is swollen, warm or painful
See your doctor or physio if
- Pain is keeping you awake or stopping you walking
- You’ve done 12 weeks of strengthening with no change
- The knee keeps giving way
Knee locking or catching may be a meniscus problem. See meniscus tear.
Strong thighs, lighter load, and keep moving. The X-ray doesn’t decide how you feel.