Knee replacement is a very common operation. It’s a very successful one too, helping to reduce pain and improve mobility for thousands of patients every year.
As with any medical procedure, though, there’s a chance that things won’t work out as planned for everybody. Over time, joint implants can wear out or fail, for a variety of reasons.
This is where revision knee replacement comes in. But what exactly does a revision procedure involve – and what are the implications? Here’s a brief guide to the key issues.
What do doctors mean by “revision knee replacement”?
“Revision replacement” or “revision surgery” is an operation to alter a patient’s original knee implant (or prosthesis). This usually means replacing the implant with a new one. In some cases, it can mean replacing part of the implant.
How common is revision surgery?
It’s quite rare. The latest data from the National Joint Registry – the gold standard when it comes to replacement statistics – says the chance of a knee replacement patient needing a revision within 13 years of their original operation is “less than 5%”. “In the great majority of patients,” they add, “the implant will last well in excess of 20 years.” That certainly fits with our experience here in the clinic. We quite commonly see patients with knee replacements that are more than 30 years old.
Why do people have knee revisions?
There are a few different reasons why you might need revision replacement. They include:
Loosening – the implant no longer attaches firmly to the bone or the surrounding ligaments
Wear – the implant surfaces begin to wear away, perhaps after many years of use
Fracture – the implant suffers sudden damage, for example during a fall
Infection – bacteria settle in the implant and the patient’s body isn’t able to clear it
Instability – damage to surrounding ligaments prevents the implant from working properly
These sorts of issues can lead to stiffness and swelling around the knee, or mobility and stability problems. They can be uncomfortable or painful too. A serious infection in a knee implant is a medical emergency and needs to be treated urgently.
Is a revision essentially the same as a first-time knee replacement?
No. Knee revision is a bigger and more complicated operation than the original procedure, particularly if the old implant is being replaced. There a few reasons for this:
Surgery time – the old implant has to be carefully removed before the new one can be introduced
Bone loss – the operation often involves removing more bone to accommodate the new implant
Fixation – the surgeon may need to place stems into the bone endings to ensure a secure fix
These factors raise the risk of potential complications, and increase the time it takes to fully recover from the surgery afterwards. It’s also worth bearing in mind that revision implants typically don’t last as long as first-time replacements.
Do I need revision surgery?
This is the key question, and one you would need to carefully explore with your consultant. Firstly, they will want to do a thorough examination to see what’s going on with your knee and why you’re experiencing problems with the original implant. They’ll likely want to order x-rays, bone scans or blood tests as part of that investigation, too. These things will help you to weigh up the pros and cons of a new operation together: the potential risks, the possible recovery time, the lifestyle impact, the “cost-benefit ratio” of undergoing the procedure. You will also need to think carefully about alternatives to revision. These range from a new course of physiotherapy or pain relief to walking aids and tailored strengthening plans. Ultimately, revision surgery is one of those areas of orthopaedic medicine that’s highly personal – very much a one-size-doesn’t-fit-all situation. While many patients do benefit from revision, it’s not the right course of action for everyone. It’s important to lay out all the facts, and think through all the implications, before pressing ahead.
For further reading…
Do I need a knee replacement? (blog)
What can the National Joint Registry tell you about knee replacements? (blog)
Information on knee replacement and some frequently asked questions (National Joint Registry article)
