Osteoarthritis (OA) of the knee joint is a common cause of chronic pain, disability and impaired quality of life. Knee OA affects ~ 1 in 5 adults over 45 years, with many requiring major knee surgery to alleviate pain and restore mobility. However, > 1 in 5 patients will continue to suffer from pain despite surgery. It remains largely unknown who will fail to respond, and why.~Chronic postoperative pain may be linked to a particular type of pain, that is not only driven by the joint damage itself but by changes in the central nervous system (central pain). Several lines of evidence support this idea, but there is a need for a better understanding of the underlying mechanisms as well as a better tool to differentiate between peripherally- and centrally-augmented knee pain in order to identify who will benefit the most from knee surgery.~To this end, the proposed research is a feasibility study aiming to provide proof of concept for a future main trial. The study combines the diagnostic power of non-invasive imaging with experimental approaches to investigate central pain by modelling the peripheral effects of knee surgery. This will provide novel insights into the contribution of peripheral and central pain mechanisms in knee OA which can pave the way for better treatment results.~This study is expected to last for one year. It is funded by Versus Arthritis Pain Centre and forms part of a wider scientific project aiming at increasing knowledge and understanding of OA pain.
UP-KNEE study is a feasibility, double-blind, placebo-controlled randomised parallel study in participants with radiographically defined knee OA, and with self-reported chronic knee pain.