Total hip replacement – also called total hip arthroplasty – and total knee replacement (total knee arthroplasty) are surgical procedures routinely offered to treat severe osteoarthritis and joint damage. As orthopaedic surgeons, our aim is to provide patients experiencing debilitating symptoms with relief from pain and to restore function, mobility and quality of life. However, outcomes may vary and it can be difficult to predict with accuracy an individual’s likely pain and function levels after surgery.
Study into pain levels and mobility after joint replacement surgery
A study by researchers at the University of East Anglia, published in the Bone Joint Journal in 2021, set out to determine whether patients undergoing total hip arthroplasty and total knee arthroplasty follow a particular trajectory in terms of their pain levels and mobility after surgery.
Methodology
The Oxford Hip Score (OHS) and the Oxford Knee Score (OKS) were designed to assess levels of pain in patients who’ve had (or are having) total hip and total knee replacement surgery. They are one of a range of patient-reported outcome measures routinely used to assess how patients are coping and the levels of pain and function they have.
Between 2009 and 2010, 20,089 patients who’d received a total hip arthroplasty and 22,489 who’d received a total knee arthroplasty were sent OHS and OKS questionnaires. These questionnaires were sent at regular intervals – six months, one year, three years and five years after surgery. Certain criteria (including age, BMI, index of multiple deprivation, sex, ethnicity, geographical location, American Society of Anesthesiologists grade and baseline OHS and OKS score) were used to predict what sort of trajectory patients would follow in terms of their post-surgical levels of pain and functionality.
Findings
The researchers found that, on average, patients who undergo a total hip arthroplasty or total knee arthroplasty receive maximum improvement in their pain levels and functionality within 12 months of surgery. They identified two trajectories that patients are most likely to follow. The majority (70%) were categorised in the study as “level 1”. These patients experience a high level of improvement which is sustained over a five-year period. The remainder – “level 2” also experience sustained improvement, but at a lower level.
The factors that predict good 5-year outcomes
While factors like social deprivation and BMI might have been expected to predict levels of pain after surgery, researchers found this was not the case following total hip arthroplasty and of only limited value in predicting pain following total knee arthroplasty. It was a similar picture in terms of predicting someone’s function levels after surgery. However, a much more reliable way of predicting how a patient would fare in the five-year postoperative period was by assessing their pain and function levels six months after surgery.
The researchers acknowledge that their findings appear to contradict several previous studies, which appeared to show a link between factors like preoperative pain and function, age and even mental health, as a predictor of likely surgical outcomes.
However, the East Anglia study found clear links between how someone is performing six months after surgery and how they are likely to perform in the five-year postoperative period. They point out that reviewing patients at this crucial six-month juncture can provide a reliable prognosis for the next few years and may help to decide what a routine monitoring pathway should look like.
How to increase the chance of good outcomes following joint replacement
If you are due to undergo a total hip arthroplasty or a total knee arthroplasty, there are steps you can take to improve the chances of a positive outcome. We call this prehabilitation and measures might range from eating a healthy balanced diet prior to surgery through to losing weight to reduce the impact on your joints and doing exercises to improve your muscle strength.
Joseph Queally undertakes a full assessment of a patient’s overall health and wellbeing prior to joint replacement surgery and makes recommendations to ensure the best possible chances of good outcomes. If you are interested in discussing total hip arthroplasty or total knee arthroplasty, contact us for an appointment.
