Investigation of inflammation in knee replacement patients
Research type
Research Study
Full title
Investigating inflammation as a cause of pain following total knee replacement
IRAS ID
255571
Contact name
Nicholas Kalson
Contact email
Sponsor organisation
The Newcastle upon Tyne Hospitals NHS Foundation Trust
Duration of Study in the UK
1 years, 6 months, 1 days
Research summary
Research Summary
Total knee replacement (TKR) for arthritis is one of the most commonly performed operations (three million annually worldwide). Although most patients have reduced knee pain post-surgery, 20% (>600,000) don’t, and many regret having the operation. Outcomes have not improved since 1980 despite better implant design and surgical technique.
In most cases a cause, such as an incorrectly positioned implant, cannot be found so no treatment is available for this remorseless pain. There is an urgent need to discover the cause(s) of pain.
We have recently found that patients in pain, having repeat surgery on their TKR for scarring inside the joint causing reduced knee movement, have dramatic inflammation in the knee. This suggests an exaggerated inflammatory response after surgery could be responsible for pain generation. Several molecules (proteins) that cause inflammation and pain were found; excitingly they could be targeted by specific medications that interfere with their function to reduce inflammation levels and potentially pain. This research aims to determine whether patients with pain, with no identifiable or treatable cause, have knee inflammation. To do this we will analyse the liquid inside the TKR, which we know from our previous research is a valuable source of information on knee inflammation.
If we find inflammation, in particular those molecules that are associated with pain and can be targeted by medicine, a new treatment opportunity is provided e.g. injecting medicine into the knee to dampen down inflammation and reduce pain, giving patients a normal life and avoiding further expensive knee surgery.Summary of Results
Total knee replacement (TKR) is a proved and effective treatment for arthritis, with more than 100,000 performed each year in England and Wales. However, 10-20% of patients continue to suffer pain following knee replacement surgery. The cause for this is not currently known and there are no treatment options.
In this study we have explored whether there is chronic inflammation in the knees of patients with persistent pain following TKR.
We have, for the first time, obtained fluid samples from patients with painful knee replacements and patients with well-functioning, pain free knee replacements.
We have studied this fluid in the laboratory and found elevated levels of inflammatory and pain mediators.
This gives us new insight into the cause of pain in this large patient group.
We are now using this information to treat patients with anti-inflammatory agents and to modify our surgical technique to reduce inflammation post TKR. Ultimately we aim to improve outcomes for this patient population and reduce the incidence of chronic pain.
REC name
North East - Newcastle & North Tyneside 1 Research Ethics Committee
REC reference
19/NE/0359
Date of REC Opinion
31 Jan 2020
REC opinion
Further Information Favourable Opinion