This is the editor's interpretation of a paper published in the orthopaedic literature in 2009 - our attempt to make relevant medical articles accessible to lay readers. If you want to read the original it is easy to ask your librarian to obtain a reprint for you from any medical library.
The authors address the problem of distressing pain in patients who have had total knee replacement but in whom investigations have revealed no obvious cause for the pain.
The authors discuss the most common causes of pain persisting after total knee replacement, and the investigations - clinical evaluation, blood tests, diagnostic imaging and microbiological analysis - used to try and unravel the problem.
They stress that such pain must be investigated early, and that it is important to involve a pain specialist. The investigating team also needs to be multidisciplinary, involving clinicians from various disciplines and including the family doctor. Tackling the problem early may avoid anxiety and depression, together with the health problems that may accompany these symptoms. The authors feel that a pain clinic offers the best environment, as generally longer appointment slots allow for for detailed investigation.
While investigations are underway, analgesics need to be adequate. After the initial pain of the knee replacement has been covered with pain killers (analgesics), if pain persists it is likely that the routine post-op prescriptions have ended, and physiotherapy may also have ended, so continuing and increasing pain may lead to inactivity and stiffness of the joint. The World Health Organisation (WHO) have published an 'analgesic ladder' - a stepwise progression of pain management - to help clinicians manage the patients pain adequately while investigations are continuing.
The authors go on to discuss several possible causes of persistent pain after total knee replacement, and the KNEEguru suggests that you try and obtain the original article to read about these in detail. Briefly their list includes -
Wrapping up their paper, the authors emphasise that the investigation and management of the persistently painful knee after total knee replacement requires a multi-disciplinary approach. They stress that it is important to adequately manage the pain during the period of investigation. In those patients where there are no immediate indications for surgery, they have found that most patients find their pain settles if given time and adequate pain management and revision surgery should not be rushed into on the basis of pain alone.