Is Knee Replacement Surgery Right for You?

Knee replacement is a good operation for the right person at the right time. The hard part is knowing whether you are that person yet. This guide sets out who benefits, who should wait, and what to try first.

What knee replacement actually does

In an arthritic knee, the smooth cartilage covering the ends of the bones has worn away. Bone rubs on bone. That is what causes the pain, the stiffness and the grinding feeling.

A knee replacement does not give you a new knee. It resurfaces the worn ends of the bones with metal, and puts a smooth plastic spacer between them. The ligaments and muscles around the joint are yours and stay yours. That is why the result depends so much on the rehabilitation afterwards.

Who should consider knee replacement

Severe knee osteoarthritis

In advanced arthritis the cartilage is gone and the bones are rubbing directly against each other. This shows on a standing X-ray as loss of the space between the bones. Pain at this stage is usually constant rather than occasional, and it often wakes people at night.

Pain that has not responded to anything else

If pain continues despite medicines, physiotherapy and joint injections, tried properly and for long enough, surgery becomes a reasonable option. The key words are properly and long enough. Two weeks of physiotherapy that you stopped because it hurt does not count as a fair trial.

Deformity or the knee giving way

As arthritis progresses the leg can bow outwards or inwards, and the knee can feel unstable. Once the alignment changes, the load concentrates on the worn side and the wear speeds up. A knee that buckles is also a falling risk.

Your life has shrunk around the knee

This is the one that matters most and is measured least. If you have stopped walking to the market, stopped going to functions because of the stairs, or stopped travelling, the knee is deciding how you live. That is a stronger reason to operate than any X-ray finding.

Who should wait

Knee replacement is not urgent. Waiting rarely makes the operation harder, so there is time to be sure.

• Your pain comes and goes, and there are good weeks.
• You have not tried physiotherapy properly yet.
• The X-ray shows mild or moderate wear only.
• Only one part of the knee is worn. A partial knee replacement may suit you better.
• Your diabetes or blood pressure is not yet controlled. Fix that first, because it lowers the risk of infection.
• You have an infection anywhere in the body, including teeth or urine.

What to try before surgery

A large share of knee pain improves without an operation. These are worth a fair try first.

• Losing weight. Every kilogram you lose takes several kilograms of force off the knee with each step.
• Strengthening the thigh muscles. A strong quadriceps takes load off the joint. This is the single most useful exercise for knee arthritis.
• Pain medicine, used sensibly. Read our guide on how much paracetamol is safe in a day.
• A joint injection. This can settle a flare and buy time.
• Changing the activity, not stopping it. Cycling and swimming load the knee far less than stairs and squatting.

How the decision is actually made

Three things are put together: how the pain behaves, what the examination shows, and what a standing X-ray shows.

Ask for a standing X-ray specifically. A film taken lying down lets the joint space open up, so the arthritis looks milder than it is.

The X-ray alone never decides it. Plenty of people over sixty have arthritis on X-ray and very little pain. Plenty of people in real difficulty have films that look only moderate. The picture and the person have to be read together.

Recovery, honestly

Most people stand and walk with support very soon after surgery. Walking without support, driving, and stairs come back over the following weeks, at different speeds for different people.

What decides your result more than anything is doing the exercises. A knee that is not moved becomes stiff, and a stiff knee is difficult to fix later. Read more about recovery after surgery.

The realistic goal is a knee that lets you walk, sleep and manage stairs without pain. It is not a nineteen year old knee, and any surgeon who promises you one is overselling it.

Risks worth knowing

These are not common, but they are real, and you should hear them before you decide: infection, blood clots in the leg or lung, stiffness, ongoing pain in a small number of people, and loosening of the implant years later which may need revision surgery.

Frequently asked questions

How do I know if I need a knee replacement?

When pain is constant rather than occasional, wakes you at night, keeps shortening the distance you can walk, and has not responded to medicine, physiotherapy and injections tried properly. A standing X-ray and an examination together give the answer. Age on its own is not the reason, and an X-ray on its own is not the reason.

Am I too young for knee replacement?

Age matters because implants do not last forever, so a younger patient is more likely to need a revision later. That is a reason to try everything else first, not an absolute bar. If the joint is destroyed and life has stopped, age alone should not decide it.

Can both knees be done at the same time?

Sometimes, and it is called bilateral knee replacement. It suits people who are otherwise fit, because it means one anaesthetic and one recovery. It is not suitable for everyone, and it depends on your heart, lungs and general health.

What happens if I delay the surgery?

Knee replacement is not urgent, so delay is usually safe. What can happen over a long delay is that the leg bows further and the thigh muscles waste from not being used, and both of those make recovery slower afterwards. Keep the muscles working while you decide.

How long does a knee replacement last?

Most last many years, and how long depends on your age, weight, activity and the implant. Nobody can give you a guaranteed number for your own knee. If it does wear out, revision surgery is possible.

Getting an assessment

If knee pain is deciding what you can and cannot do, it is worth finding out exactly what is causing it. Call +91 6355 991 466 to arrange an assessment at Vedaant Orthopaedic Center in Surat, or read more about knee replacement surgery.

Trusted sources and further reading

This article is general information reviewed by Dr Dev Padia. For more on the conditions and treatments mentioned, see the pages below.

• Partial knee replacement — an option for one worn compartment.
• Revision knee replacement — if an implant later fails.
• OrthoInfo: Total Knee Replacement — American Academy of Orthopaedic Surgeons.
• NHS: Knee replacement — UK National Health Service.

The information on this website is for general guidance and does not replace a personal medical consultation. Please consult a qualified doctor about your own symptoms.