“It’s there and I’m stuck with it” – chronic knee pain after knee joint replacement
I share an office with an Emeritus Professor of Orthopaedic Surgery. He snorted at me one day, and showed me the stats from our national joint register database where I saw that while the main reason given for revision of a total hip joint was dislocation, and pain was the sixth most common reason given; in the case of revision of knee joint replacements, persistent pain was the most common reason given.
Some studies have shown between 6 – 30% of people receiving total knee joint replacements have ongoing pain months after their immediate post-surgical recovery. With knee joint replacement such a common surgery for osteoarthritic knees, and some reports of up to 33% of the adult population having OA of the knee, that’s a lot of people who continue to have pain!
It’s not clear why some people go on to develop chronic pain after surgery, but some vulnerabilities include having had persistent pain in the past, having psychosocial factors present such as unhelpful beliefs (hurt = harm) or depression, anxiety or other psychopathology, and having other unhelpful health habits such as smoking. It’s certainly an aspect of post-surgical pain that I’m interested in because of the large number of surgeries that are performed – and the relatively high rate of dissatisfaction with the outcome (one study estimated 1 in five people were not happy with the outcome, and satisfaction with pain relief varied from 72-86% and with function from 70-84% for specific activities of daily living, Bourne, Chesworth, Davis, Mahomed & Charron, 2010).
How well people accept, adapt to, or cope with persistent pain after a total knee replacement varies. In a study by Jeffery, Wylde, Blom, and Horwood (2011) qualitative methodology was used to begin to understand how people live with pain when the ‘fix’ they were hoping for doesn’t work out as well as they wanted.
These participants were recruited 12 months after TKJR, a procedure they’d had in the UK’s National Health Service. They all reported moderate to severe pain (as part of another research study), and had not had revision surgery. Because of the methodology employed, quite a small group of participants were interviewed (a total of 28 were interviewed until ‘data saturation’). Data saturation, in this case, occurred when interview transcripts had been coded using thematic analysis, and no new codes emerged. (Thematic analysis has some similarities with grounded theory, btw, but differs in that isn’t a complete methodology)
Cutting to the chase, several themes emerged from this analysis:
- The degree of acceptance or adjustment to ongoing pain wasn’t related to the degree of pain experienced
- Adjustment or acceptance depended on various factors including whether they were better, or worse off since surgery, as well as the input pre- and post-surgery by the surgeon
- Participants reported they felt abandoned by surgeons – and discussed the kinds of support they would have liked
It’s important not to over-interpret the findings from this study, but I did think it interesting that about half of the respondents didn’t appear overly concerned about their pain – the authors of the study thought this indicated acceptance. These participants said things like
“. . .it’s just a case of you’ve gotta face up to it and you’ve gotta get on with life and you’ve gotta accept it” (John, age 74 years).
“. . .Once again, it’s part of my life, you know, I just don’t, I don’t think about it much. . .” (Phyllis, age 81 years).
The other half of the participants were not as accepting, and said things like
“Depressed, totally depressed, sad, miserable, charred off, all the things that go with that that you can think of” (Dennis, age 59 years).
“. . . I just don’t know what to do with it.. . . I was in so much pain I said to my husband, and it’s only him I’d tell, I wouldn’t tell the family, I said if I don’t do something I shall, well I shall jump off the bridge” (Sally, age 75 years).
The important point was made by the authors: the degree to which people accepted their pain was almost always related to “…individuals’ perceptions of improvement or deterioration in circumstances since their TKR. Those perceiving an improvement in pain or functioning expressed little distress and a more accepting attitude.”
One of the other studies I looked at while researching this post was a paper by Riddle, Wade, Jiranek and Kong (2010) which identified that pre-surgical pain catastrophising predicted post-surgical pain outcomes.
I wasn’t surprised at this – it makes sense that someone who catastrophises is likely to (a) be predisposed to having an over-active amygdala which will influence the way in which the whole sensitive nervous system responds to a planned insult to the body and (b) also interpret post-operative pain in an equally alarmed way. This doesn’t bode well for post-surgical recovery involving mobilising on a painful and possibly swollen knee, and especially in any hospital system that wants people discharged as soon as possible so the bed can be available for someone else.
We need to be cautious, though, about the way the Riddle, et al., study is interpreted – conclusions we can draw from many studies such as the Bourne, et al., (2010), Jeffery, et al., (2010), and many non-joint-replacement studies on back pain and disability show that it’s the distress, or how well the person adjusts to having ongoing pain, and the impact that this has on function, treatment seeking and well-being in general, not the pain intensity that seems to matter.
Returning to the Jeffrey, et al. (2011) study, presurgical preparation by the surgeon seemed to play an important role in how well people accepted ongoing pain. Those that had been advised that pain is likely seemed to view pain as normal, and were therefore more able view the pain as able to be tolerated.
Where am I going with this? The main points I want to make are these:
- post-TKJR pain is common, with up to 30% of people continuing to have pain for 12 months after surgery
- persistent pain is the most common reason for revision of TKJR
- the degree of pain is not directly related to distress or function
- there are several vulnerability factors that can be identified before surgery that are correlated with post-surgical pain
- at least some of these factors can be addressed before surgery, while how we respond immediately after surgery can also have an impact
Maybe one of the best ways we can help people cope is to inform people prior to surgery that persistent pain afterwards is common, therefore not an indicator of something awful - then after surgery, give people with risk factors such as catastrophising, health anxiety, distress, low mood and limited social resources adequate and appropriate chronic pain self management sooner rather than later.
And perhaps surgeons could remember that surgery is not a quick fix for up to one third of their knee joint replacement patients.
Bourne, R. B., Chesworth, B. M., Davis, A. M., Mahomed, N. N., & Charron, K. D. (2010). Patient satisfaction after total knee arthroplasty: who is satisfied and who is not? Clinical Orthopaedics & Related Research, 468(1), 57-63.
Jeffery, A., Wylde, V., Blom, A., & Horwood, J. (2011). “It’s there and I’m stuck with it”: Patients’ experiences of chronic pain following total knee replacement surgery Arthritis Care & Research, 63 (2), 286-292 DOI: 10.1002/acr.20360
Riddle, D. L., Wade, J. B., Jiranek, W. A., & Kong, X. (2010). Preoperative pain catastrophizing predicts pain outcome after knee arthroplasty. Clinical Orthopaedics & Related Research, 468(3), 798-806.
Not sure why medicine is so resistant to consider osteoarthritis a chronic pain condition. It’s still one of the last bastions of the biomedical model, the ‘if it hurts, we just cut it out and replace it with a new one’ idea. We learned years ago that this doesn’t work with most chronic pain conditions (think amputating limbs with neuropathic pain), so why should we expect it will work with other types of chronic pain? Just because we can see joint space narrowing on an x-ray doesn’t necessarily mean that’s the pain generator, right? How often has that been shown in chronic LBP or neck pain?
What would happen if we flipped this question around? When it ‘works’, what is the mechanism behind that? I would propose that sitting a patient down, showing them an x-ray of their joint before the surgery, and then one after the surgery, has got to be one of the best placebo mechanisms available. It’s right there, in black and white in front of you – you should feel better now.
Just my two cents worth.
Hi Dave
I think it could be because by comparison with LBP the results from joint replacement can be quite successful – a 60% positive outcome rate is pretty good by comparison with most other chronic pain conditions! And it’s intuitively appealing too – if we think of the human body as simply an organic biomechanical machine rather than a dynamic, constantly remodelling organism!
I still have arguments with one or two docs who don’t want to recognise that OA has a central sensitisation component (mind you, one of those docs doesn’t ‘believe in’ central sensitisation!).
What is remarkable is that the participants in this study were moderately to severely affected by pain – and yet half of this sample were fairly accepting of this and not terribly distressed by their pain. Now if only I could get the docs to understand that having pain is not inevitably associated with needing or even wanting treatment!
What a great post, Bronnie.
Thank you for this.
I absolutely agree with you that early pre- and post-rehabilitation could greatly benefit from the approaches and strategies that we traditionally find in a pain management environment and early detection of the risc factors is paramount. And considering the neurobiological science behind cybernetics in biological systems there is a central mechanism that plays a big and a hugely underestimated part.
I would add, though, a very important point regarding ongoing post-surgical pain. This point deals with peripheral, spinal and central mechanisms. In many of these studies it doesn’t look like they have calibrated the studies in terms of dominating pain mechanisms. Kehlet, Jensen and Woolf have looked at some of the biggest risc factors for on-going post-surgical pain (Kehlet 2006) and found that neuropathic pain is a major component.
Given the circumstances in the surgical environment it is very likely that a neuropathic pain state can develop: It could be present but unrecognized prior to surgery, it could develop in relation to the surgical techniques and it could technically develop in relation to the positioning of the patient during the procedure.
The problem of course with neuropathic pain is that you can find it present in a spectrum from a mild to a severe state (eg. CRPS). One of the major clinical problems with this condition is that it makes for a very uncontrollable post-surgical recovery: it’s often extremely sensitive to mechanical stimuli (kind of makes movement therapy quite a challenge…), it has spontaneous, latency and wind-up capabilities and it often wrecks the patients sleep hygiene.
I can certainly imagine several psychosocial factors being influenced by the neuropathic component including fear-avoidance in relation to hyperpatia and paroxysms and a challenge in pacing movement, exercise and activity with latency and wind-up phenomena.
I work with post-surgical patients in an out-patient orthopeadic setting and I personally believe that the neuropathic component is a potential bomb under the recovery period. Therefore it needs to be identified as early as possible and measures be taken accordingly (although that is quite the challenge in a mono-professional setting like the one I’m in).
Just had to add this point to a brilliant post. Thanks.
Love to have you back on the web.
Kehlet H, Jensen TS, Woolf C (2006) Persistent postsurgical pain: risk factors and prevention. Lancet 367: 1618-25
Kind regards
Adam Bjerre
Physiotherapist
Denmark
Thank you so much Adam! And I couldn’t agree with you more about under-recognised neuropathic pain post-surgically. A study I’m about to start on (once the quake dust has settled a little) is identifying the number of people presenting for joint replacement who have pre-existing central sensitisation (eg the Yunus cluster of problems such as irritable bowel syndrome, depression, TMJ dysfunction, migraine etc) – then follow these people up to see how this influences the prevalence of persistent pain. It will be interesting! At least in your patient’s case, they have an informed and enthusiastic clinician working with them – all the best with your work, I know how hard it can be without an interdisciplinary team alongside you.