Working in an orthopaedic surgery department is quite enlightening. Along with discussions about ceramic vs metal implants and cartilage regeneration (I work with a team of researchers looking at how to create replacement cartilage), the topic of what counts as a surgical success in knee surgery also comes up from time to time. Knee joint replacement isn’t as successful as hip joint replacement for a number of reasons including the complex nature of the joint, the way the joint capsule is disrupted during surgery, and the knee can apparently feel quite different from the original knee.
What this means is there can be quite a mismatch of expectations for people who believe very strongly that there should be no pain and they should have a completely normal knee joint after surgery. In fact, in the NZ National Joint Registry, the main reason recorded for knee joint revision is pain.
Naturally, the problem of pain after surgery is something surgeons and researchers are also interested in. Many studies have shown psychological factors such as catastrophising (thinking the worst) and low mood are associated with poorer outcomes (Riddle, Wade. Jiranek, & Kong, 2010; Roth, Tripp, Harrison, Sullivan & Carson, 2007; Shelby, Somers, Keefe, Pells, Dixon & Blumenthal, 2008). The outcomes looked at so far include length of stay in hospital at the time of surgery, analgesia use during surgery, increased disability after surgery and revision rates.
Now, one solution to this problem could be simply not performing joint replacement surgery in people who are depressed and tend to think the worst. The problem is that two of the strongest predictors for looking for treatment are – you guessed it: low mood and catastrophising (and disability). Another solution is to provide intervention after surgery to target the people who tend to become fearful – perhaps an enhanced level of physiotherapy for this group, while the less vulnerable may even require less. Some studies have also looked at giving better education about what the surgery entails and the expected outcomes, and doing this before the person undergoes surgery, while another study has looked at providing a pain coping skills training course prior to surgery (Riddle, Wade, Jiranek & Kong, 2011). The outcomes from this last approach were promising, although it was a very small sample size, and the follow-up was for only two months.
There are a number of problems with implementing any of these approaches in clinical practice, at least in the system I’m most familiar with (NZ):
- Many orthopaedic surgeons still discount the importance of psychological factors, and consider the information they provide completely adequate for presurgical preparation
- It’s difficult to give someone different or special treatment based on psychological factors within a usual clinical setting without also inadvertently giving people a label that may change how they are responded to
- Any additional intervention will have an up-front cost (not good for cost accountants!)
- These treatments need specially trained clinicians who understand the measures being used, the rationale for treatment, and the type of treatment needed – and because these are psychological factors and surgery is conducted in a “physical” hospital, this is unfamiliar territory for many
- Patients may not be very comfortable with a treatment that focuses on thoughts, emotions and pain
It seems to me, and from the results from a recent study looking at analgesic use after surgery, that an argument simply based on the cost of failing to go ahead with effective management of psychosocial factors would make sense. Here’s the detail:
Fuzier, Serres, Bourrel, Palmaro, Montastruc and Lapeyre-Mestre (2014) conducted a large study of patients in the Midi-Pyrenees region of France. They examined the medical records of all 1939 patients who had knee arthroplasty, and compared the drug use (what was dispensed) at four times – 12 months before surgery, 2 months before surgery, and 10 months before and after the knee surgery. What they found was an increase in analgesic, antineuropathic and opioid drug use in the 12 months after surgery. The actual percentage of patients requiring more medication is astonishing: 47% of people needed more analgesia, 8.6% needed more antineuropathic medications, and 5.6% needed more opioids. That’s a whole lot of drugs!
These researchers also analysed a number of other variables associated with the medication changes, and made some more understandable findings:
- people having total knee replacement surgery were at a greater risk of using more medication than those having unicompartmental surgery (half a joint)
- people with high levels of preoperative pain along with “psychiatric vulnerability” were at greater risk of having increased neuropathic medications prescribed
- but older people were less likely to be prescribed additional medications
Unfortunately, this study didn’t identify the particular “psychiatric vulnerabilities” of the patients who participated – from the paper it looks like data was extracted from clinical records, so psychiatric disorders such as depression, anxiety and so on are the likely culprits. We don’t therefore know whether catastrophising contributed to the medication use – but given the results from at least 20 studies I have in my database, I think it’s probably likely.
Medications are not cheap. While they’re quick to prescribe, dispense and take, they cost not only in fiscal terms (which is a serious consideration, nevertheless), but also in side effects – and more importantly, in loss of personal locus of control. What I mean by this is that these are people who haven’t been given the opportunity to develop pain self management skills. They will continue to catastrophise, and perhaps even more so after surgery because their fears have been confirmed. Maybe it’s cheaper and more humane to bite the bullet and begin giving people appropriate psychosocial treatment before, during and after surgery.
Fuzier, R., Serres, I., Bourrel, R., Palmaro, A., Montastruc, J., & Lapeyre-Mestre, M. (2014). Analgesic drug consumption increases after knee arthroplasty: A pharmacoepidemiological study investigating postoperative pain PAIN®, 155 (7), 1339-1345 DOI: 10.1016/j.pain.2014.04.010
Riddle, D. L., Keefe, F. J., Nay, W. T., McKee, D., Attarian, D. E., & Jensen, M. P. (2011). Pain coping skills training for patients with elevated pain catastrophizing who are scheduled for knee arthroplasty: a quasi-experimental study. Archives of Physical Medicine & Rehabilitation, 92(6), 859-865.
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.
Roth, M. L., Tripp, D. A., Harrison, M. H., Sullivan, M., & Carson, P. (2007). Demographic and psychosocial predictors of acute perioperative pain for total knee arthroplasty. Pain Research & Management, 12(3), 185-194.
Shelby, Rebecca A., Somers, Tamara J., Keefe, Francis J., Pells, Jennifer J., Dixon, Kim E., & Blumenthal, James A. (2008). Domain specific self-efficacy mediates the impact of pain catastrophizing on pain and disability in overweight and obese osteoarthritis patients. Journal of Pain, 9(10), 912-919.