Revision Knee Replacement
Unfortunately some patients with a knee replacement have problems with their knee. This can occur early or much later following many years of successful function and pain relief with knee replacement.
There a number of causes of pain and functional problems following knee replacement and some of these are treatable with a revision knee replacement. This involves removing the old implant and starting again, rebuilding the knee using more complicated implants.
When there is a reversible cause for the patient’s symptoms, revision knee replacement performed by an experienced revision knee surgeon, will yield good results.
If you are experiencing problems with your knee replacement such as pain, instability, stiffness, swelling, change in shape of the knee/leg or functional disturbances then it is sensible to investigate this further. After listening to your story and problems, we would examine the problem knee and usually arrange certain test which may include blood tests and specialist X-rays or scans. Occasionally we will suggest that biopsy or arthroscopy of your total knee may be necessary to help reach a diagnosis. In some cases, for example with infection or loosening we will offer you a revision knee replacement (‘re-do knee replacement’) which would mean a short spell in hospital and then a recovery period similar to a standard knee replacement with good results (as presented and published by our group).
Problems with knee replacements which occur early (first few years)
The kind of problems that can occur very early are often due to technical issues creating instability or pain and stiffness. Unfortunately infection of the joint replacement happens in approximately 1% of all knee replacements, but this rate can be higher if there are additional risk factors.
When we treat infection in joint replacement this should be part of a multidisciplinary team (MDT), with careful discussion with microbiologists to establish the causative organism and the most appropriate antibiotic treatment. However antibiotics alone are very rarely the right option for long term management of an infected knee replacement, instead the treatment requires surgery either to retain the original implant but changing mobile components (for example the plastic liner) or revision surgery, either in one or two surgical stages often separated by many months.
There are three partners of Knee Specialists (Andrew Porteous, Nick Howells and James Murray) who work as part of the regional MDT for the management of prosthetic joint infection, based at the Avon Orthopaedic Centre within Southmead Hospital.
Problems with knee replacements later on in their life (usually from 10 years onwards)
Unfortunately infection can also happen late, due to spread from other sites in your body. For example if you have a well-functioning knee replacement that starts becoming hot, swollen and painful, particularly if you have had a recent infection, then you should seek specialist advice.
More commonly after about 10 years of service, knee replacements may start to fail by the implant loosening from the bone. The movement can then cause erosion of the supporting bone making subsequent revision knee surgery more complicated. Another way that implants can fails is by the plastic (really Ultra-high molecular weight polyethylene) bearing surface wearing thin and even breaking. This can create a very significant reaction which often causes swelling, pain and sometimes bone erosion.
In summary if a previously well-functioning knee replacement becomes painful or swollen then it is very worthwhile for this to be investigated.
Other causes of pain
There has been a lot of research demonstrating that unfortunately a group of patients have persistent pain following knee replacement in approximately 2/10 patients. This is usually less than the knee pain of arthritis and often improves with time. There are a number of theories around this, but it is important to assess whether there is any underlying cause that could be corrected, for example infection. However despite careful assessment sometimes we may find that there is no surgically remedial cause for your pain, but at least this will allow us to direct you to the appropriate specialist pain management services.