Knee replacement problems: When is revision surgery needed?

Photo of patient and doctor talking

If complications such as an arise, revision surgery on the knee replacement can’t be avoided. For other problems, you should only have surgery again if the doctors are sure what the cause of the problem is and it can be treated with a surgical procedure. If you don’t feel sure about it, you can get a second opinion.

Further (revision) surgery is performed on about 5 to 10% of all artificial knee joints within 10 years. It’s not always easy to tell whether revision surgery is needed when problems with a knee replacement arise. There are three possible situations:

  • An acute complication: Revision surgery may be needed after an or a bone fracture, for example.
  • Problems with the knee replacement: Revision surgery is often needed when there are problems with the knee replacement itself, such as loose parts. Sometimes there are other treatment options, or there are medical or personal reasons against revision surgery.
  • Knee problems with other causes: Your knee may have problems that have nothing to do with the knee replacement or the joint. Then it’s not a good idea to have revision surgery, and it might even make things worse.

If your doctor advises you to have revision surgery, ask what they suspect is causing the problem and whether there are alternative treatments available. Your doctor is then required to tell you that you have the right to a second opinion free of charge before any revision surgery. It’s important to go to a specialist who has experience in the planned procedure.

What are the possible causes of pain despite having a joint replacement?

A joint replacement can relieve the pain caused by advanced osteoarthritis of the knee in many people. But up to 20 out of 100 people who have the procedure continue to experience problems afterwards. That could have many possible causes, such as:

  • An artificial joint that doesn’t fit well or hasn't been implanted properly
  • Pinched soft tissue
  • Problems with the kneecap
  • An to the artificial joint material or to the bone cement

It is normal for the knee to hurt a little for the first year following the surgery. Sometimes dissatisfaction with a prosthesis is down to having expectations that were too high.

The cause of the problem doesn't always have to do with the knee joint itself. Other possible causes include:

  • Tendon problems
  • Bursitis (an in the small, fluid-filled sacs often found near joints in the body)
  • Pain extending from your back down to your leg (such as caused by a slipped disc, for example)
  • Pain or muscle weakness caused by osteoarthritis of the hip
  • Vascular disease of the leg
  • Chronic pain disorder

Anxiety, worrying and mental illness such as can make the pain worse.

But it's important to know that you should only have revision surgery if a cause has been found for the problems – and if the procedure is expected to help. Sometimes it’s not possible to find a cause. The chances that revision surgery will be successful are low then.

An exact needs to be based on a detailed discussion of the problem. The doctor needs to know exactly what’s wrong – such as where and how severely your knee hurts, how the pain feels, and when you experience it. After that, your knee, the alignment of your leg and your posture will be examined. Blood tests and x-ray imaging can help to rule out complications like and to check the position of the parts of the knee replacement.

Loosening of the knee replacement

Revision surgery is most commonly used when parts of the knee replacement have become loose. That could be due to any of the following causes, such as:

  • Material wear and bone loss
  • Heavy strain – for instance in some jobs, or from playing intensive sports or being very overweight
  • Improper anchoring of the parts of the replacement joint

Problems caused by a loose knee replacement can only be treated with revision surgery. Sometimes there are reasons not to have revision surgery – for instance if someone is already very old and has a lot of other illnesses that would make surgery too risky.

An unstable knee

An unstable knee can cause various problems. Your knee may feel like it could give way. Or it might be painful or swollen. Sometimes it is going down stairs that is especially difficult.

The possible causes of an unstable knee include the following:

  • Ligament problems, such as a weak median (facing the other knee) collateral ligament or lateral (facing away from the other knee) collateral ligament
  • Parts of the knee replacement that aren’t positioned correctly
  • Illnesses such as rheumatism or muscle or nerve diseases
  • Being very overweight

Revision surgery may be needed if you have an unstable knee This type of surgery involves making corrections, exchanging parts of the knee replacement, or implanting a knee replacement that offers better support (a non-constrained or semi-constrained prosthesis). Depending on the cause and the severity of the symptoms, other treatments might be suitable, such as physical therapy to strengthen your muscles, or a knee brace or splint (knee bandage or orthesis).

Problems with the kneecap

After surgery your kneecap can slip sideways out of its groove. That could be caused by weak or injured ligaments in your knee or by the knee replacement not being correctly positioned. Here there may be various treatment options as well, such as physical therapy, ligament or joint capsule surgery, or the exchange of parts of the knee replacement.

Sometimes osteoarthritis gets worse and damages the cartilage underneath the kneecap. That can cause pain in the front part of the knee, especially when standing up or climbing stairs. The inner side of the kneecap can be replaced in revision surgery. But pain in the front part of the knee might also be caused by something else, such as overuse. Surgery isn’t a good idea if that is the cause.

A stiff knee

Sometimes you aren’t able to fully extend or flex your knee after getting a knee replacement. Possible causes include

  • Parts of the knee replacement that aren’t positioned correctly
  • Ligament problems
  • Joint infections or adhesions (tissue sticking together)
  • Pain

Another cause is inflammation, which causes the connective tissue in the knee to multiply. That can result in the formation of a solid, thick capsule that limits your range of motion. Doctors call this hardening of tissue arthrofibrosis (frozen knee).

Depending on the cause, a frozen knee can be treated with physical therapy, medication or special knee ortheses. Sometimes the knee is extended and flexed using an anesthetic to loosen the adhesions. This may also be done as part of arthroscopy (keyhole surgery). Revision surgery can’t always be prevented, though.

Getting a second opinion for partial knee replacements

A second opinion can be particularly worthwhile for people who have so far only had a partial knee replacement. Because it is comparatively easy to replace a partial knee replacement with a full knee replacement, revision surgery is often recommended too hastily, even when it is not actually needed.

It's best to consult a doctor with a lot of experience if you'd like a second opinion on revision surgery for a partial knee replacement. That is important because problems with partial knee replacements are not always easy to assess. X-rays may show lighter areas around the parts of the replacement joint, for instance. They can be, but are not automatically, a sign that the partial knee replacement has become loose. These kinds of lighter patches are often normal side effects of the operation and don't require treatment. The quality of the examination and the x-ray imaging can also affect this assessment.

When is urgent revision surgery needed?

Urgent revision knee surgery is needed if there are acute complications or an emergency. This is particularly the case if

  • the knee joint that has been operated on becomes infected, or
  • a bone in the knee region is broken in an accident or fall.

A joint occurs after about 1 out of every 100 operations. Most joint infections develop during the first weeks or months after the joint replacement has been implanted. A reddened, painful and warm joint is a sign of an . The joint can also become stiff and swollen. Fever and a surgical wound that is not healing or is weeping (releasing fluid) can also be signs of a joint . It's important to seek medical advice quickly if you have these symptoms.

In rare cases, a knee replacement can become infected years after surgery if from other parts of the body spread to the joint through the blood. There is often no swelling or reddening at all in these sorts of late infections. Instead, the typical signs are chronic pain or problems caused by the knee replacement loosening.

A joint can sometimes be successfully treated at an early stage by cleaning the wound, rinsing the joint, and using . Then the knee replacement doesn't have to be removed. But it might be necessary to exchange the knee replacement. Sometimes one operation is enough. Two procedures are often needed, though. In the first operation, the infected knee replacement is replaced by a dummy containing . It remains in the joint for 2 to 6 weeks, depending on which germs have infected the joint. A new joint is implanted in the second procedure.

Carr AJ, Robertsson O, Graves S et al. Knee replacement. Lancet 2012; 379(9823): 1331-1340.

Chang MJ, Lim H, Lee NR et al. Diagnosis, causes and treatments of instability following total knee arthroplasty. Knee Surg Relat Res 2014; 26(2): 61-67.

Crawford DA, Berend KR, Lombardi AV. Management of the Failed Medial Unicompartmental Knee Arthroplasty. J Am Acad Orthop Surg 2018; 26(20): e426-e433.

Hönle W, Ndubuisi O, Scheller A et al. [Painful total knee arthroplasty - operative and conservative therapy]. MMW Fortschr Med 2019; 161(14): 56-64.

Kalson NS, Borthwick LA, Mann DA et al. International consensus on the definition and classification of fibrosis of the knee joint. Bone Joint J 2016; 98-B(11): 1479-1488.

Thompson R, Novikov D, Cizmic Z et al. Arthrofibrosis After Total Knee Arthroplasty: Pathophysiology, Diagnosis, and Management. Orthop Clin North Am 2019; 50(3): 269-279.

IQWiG health information is written with the aim of helping people understand the advantages and disadvantages of the main treatment options and health care services.

Because IQWiG is a German institute, some of the information provided here is specific to the German health care system. The suitability of any of the described options in an individual case can be determined by talking to a doctor. can provide support for talks with doctors and other medical professionals, but cannot replace them. We do not offer individual consultations.

Our information is based on the results of good-quality studies. It is written by a team of health care professionals, scientists and editors, and reviewed by external experts. You can find a detailed description of how our health information is produced and updated in our methods.

Comment on this page

What would you like to share with us?

We welcome any feedback and ideas - either via our form or by We will review, but not publish, your ratings and comments. Your information will of course be treated confidentially. Fields marked with an asterisk (*) are required fields.

Please note that we do not provide individual advice on matters of health. You can read about where to find help and support in Germany in our information “How can I find self-help groups and information centers?

Über diese Seite

Created on January 12, 2022

Next planned update: 2025


Institute for Quality and Efficiency in Health Care (IQWiG, Germany)

How we keep you informed

Follow us on Twitter or subscribe to our newsletter or newsfeed. You can find all of our films online on YouTube.