There are more than 4 million people in the US who have undergone total knee arthroplasty (TKA), making it one of the most commonly performed procedures. This number, however, would likely be much higher if it were not for its elective nature and the psychological factors behind the decision to undergo the procedure. Dr Daniel Riddle from Virginia Commonwealth University’s School of Medicine, along with his colleagues,1 found that patients who expected moderate to severe pain after the procedure were 5 times less likely to undergo TKA over a 3-year period – despite previous data indicating approximately 80% of those who undergo the procedure report improved function and a reduction in pain.2,3
The investigators used data from those enrolled in the Osteoarthritis Initiative (OAI), a privately funded, multi-center, prospective, longitudinal cohort study of knee OA administered by the US National Institutes of Health. Dr Riddle and colleagues assumed that those less able to cope with pain would expect poor outcomes from TKA, and that assumptions about pain and walking ability after the procedure would be associated with the choice to delay or forego TKA entirely.
The study sample (n=3542) was structured to evaluate patient expectations reported at the 6-year follow-up vs the incidence of TKA in these patients during the following 3 years. Twenty-six percent of the study group expected moderate or worse pain after TKA; furthermore, 21.8% anticipated moderate or worse walking difficulty when recovering from TKA.
The authors explained there was no significant association between the presence of radiographic knee OA and TKA outcome expectations among the study cohort. “This indicates that people with and without knee OA had similar expectations for pain and walking difficulty outcomes following TKA,” they noted.
The research team then identified a subset of study group (n=387) who were reportedly experiencing the most pain (Kellgren–Lawrence grade of 3 or 4, a Western Ontario and McMaster Arthritis Index pain score of ≥5) in one knee, but who had not undergone TKA at the year-six data collection – a group of patients who are likely candidates to undergo TKA. However, the analysis showed that only 19.1% had a TKA during the subsequent 3 years (visit years 7 to 9).
Additional findings included:
- 6.4% of participants with moderate or worse pain expectations at year 6 had a TKA during the 3-year follow-up period; 24.9% with expectations of either no pain or mild pain at year 6 underwent TKA
- Those who expected either no or mild pain following the procedure were almost 5 times more likely (odds ratio [OR] = 4.9, 95% confidence interval [CI] = 2.2 to 11.1, P ˂ .001) to have a future TKA compared with those who expected moderate or worse pain
- Those who expected either no or mild walking difficulty during recovery were over twice more likely (OR = 2.6, 95% CI = 1.3 to 5.4, P = .009) to have TKA in the subsequent 3 years compared with participants who expected moderate or worse walking difficulty.
Summary and Clinical Applicability
Based on the study analyses, Dr Riddle and colleagues suggest that expectations of poor outcomes following TKA are being driven by potentially modifying psychological factors. “Recognizing these factors in patients with OA and treating them may improve patients’ expectations, and lead to more appropriate and timely use of TKA,” they wrote.
The authors noted that although most people who undergo TKA report little to no pain post-procedure, a quarter of the sample in their study anticipated pain outcomes that was more than typically occurs.
“It is likely that a substantial proportion of these people have unrealistically poor expectations should a TKA be needed in the future, and may not consider TKA as a viable treatment option for their knee OA,” wrote Dr Riddle and colleagues.
“The present results,” they concluded, “emphasize the role of depression and pain catastrophizing in negatively impacting expectations of potential future TKA outcomes. These risk factors may be potentially modifiable with educational, counseling and other intervention approaches.”
- There was a small sample of study participants (n=74) who had moderate-to-severe knee OA (Kellgren-Lawrence grades of 3 or 4) and WOMAC pain scores of ≥5 who underwent TKA in years 7 to 9 of the follow-up period
- Non-numeric (ordinal) scales of pain measurement and walking expectations used in OAI data may have contributed error to the measurement of expectations.
Dr Golladay is a consultant for and has received research support from OrthoSensor, Stryker, and Cayenne Medical. Dr Golladay has stock options in and has received royalties from OrthoSensor. Dr Ghomrawi is a consultant for Optum.
- Riddle DL, Golladay GJ, Hayes A, Ghomrawi HM. Poor expectations of knee replacement benefit are associated with modifiable psychological factors and influence the decision to have surgery: A cross-sectional and longitudinal study of a community-based sample. [Published online December 2, 2016] Knee. doi:10.1016/j.knee.2016.11.009.
- Beswick AD, Wylde V, Gooberman-Hill R, Blom A, Dieppe P. What proportion of patients report long-term pain after total hip or knee replacement for osteoarthritis? A systematic review of prospective studies in unselected patients. BMJ Open. 2012;2: e000435.
- Katz JN, Mahomed NN, Baron JA, et al. Association of hospital and surgeon procedure volume with patient-centered outcomes of total knee replacement in a population-based cohort of patients age 65 years and older. Arthritis Rheum. 2007;56:568–574.
This article originally appeared on Rheumatology Advisor