People on higher incomes are happier with new knees

May 21, 2013

Knee replacement surgery is a very common procedure. However, it does not always resolve function or pain in all the recipients of new knees. A study by Robert Barrack, MD and his colleagues from the Washington University School of Medicine wanted to determine if any socioeconomic factors were associated with less successful outcomes of knee replacement surgery. Their study, which appears in Clinical Orthopaedics and Related Research, published by Springer, found that lower-income individuals reported higher levels of dissatisfaction and poorer function than those with higher incomes.

Knee replacement surgery has improved enormously over the years since its inception and now includes much better and more focused component design, smaller , better and improved post-surgical care and rehabilitation. However, research into outcome measures has tended to focus on the type of component used or surgical technique rather than other factors which might affect the success of surgery, especially in younger patients. It is important, therefore, to determine whether patients are benefitting from these improvements and elucidate what factors might affect a good outcome.

The researchers analyzed more than 600 patients with an average age of 54 undergoing total knee replacement surgery at one of five major total joint centers in different parts of the United States. They were all asked details about such as education, income and employment, gender, and ethnicity and completed a retrospective questionnaire to assess their degree of satisfaction with the results of their surgery.

There was a clear relationship between income and levels of satisfaction. The study found less satisfaction with the results and greater functional limitations after the in individuals from households reporting an annual income of less than $25,000 a year. No other socioeconomic factor was related to levels of overall satisfaction with the procedure, however women and minority patients were more likely to express following TKA. Employment status and educational level had the least impact on satisfaction or function as perceived by the patient. Barrack and his colleagues point out that although this is not a causative association, it is nonetheless significant.

The authors offer a number of explanations for these findings. Previous studies citing similar associations have suggested that patients from lower income households may receive less post-acute care rehabilitation. This could have a significant negative impact on results of . It has also previously been reported that ethnic minority patients are more likely to be seen at low-volume hospitals. All the subjects in this study were seen at high-volume specialist centers which may be why the general levels of are quite low (around 10 percent) and explain the minimal impact of minority status on the results.

The authors conclude: "It is certainly possible, based on our results, that , particularly household income, may be strongly associated with satisfaction and functional results. Future studies should be directed to determining the causes of this association, and if further studies do, in fact, confirm this hypothesis, then studies of clinical results after total knee arthroplasty should consider stratifying patients by socioeconomic status."

Explore further: Lower-income patients fare better than wealthier after knee replacement, study finds

More information: Barrack, R.L. et al (2013). Impact of socioeconomic factors on outcome of total knee arthroplasty. Clinical Orthopaedics and Related Research. DOI 10.1007/s11999-013-3002-y

Related Stories

Lower-income patients fare better than wealthier after knee replacement, study finds

November 10, 2012
Patients who make $35,000 a year or less report better outcomes after knee replacement surgery than people who earn more, research by Mayo Clinic and the University of Alabama at Birmingham shows. The lower-income patients ...

Sexual function improves significantly after hip or knee replacement surgery

March 19, 2013
Osteoarthritis of the hip or knee, affecting millions of Americans each year, is known to limit sexual activity. New research presented today at the 2013 Annual Meeting of the American Academy of Orthopaedic Surgeons (AAOS) ...

Not all patients benefit equally from hip or knee replacement, study finds

April 4, 2013
Only half of people with arthritis who had a hip or knee replacement reported a significant improvement in pain and mobility after surgery, according to a new study led by Women's College Hospital and the Institute for Clinical ...

Knee replacement not an 'easy solution' for obese patients

October 24, 2012
Obese patients have a greater risk of complications following total knee replacement surgery, including post-surgical infections, according to a new literature review recently published in the Journal of Bone and Joint Surgery ...

Men play post-op catch-up

June 29, 2011
Although women generally have worse knee function and more severe symptoms before undergoing surgery for knee replacement than men, they recover faster after the operation. Men take longer to recover but, after a year, they ...

Computer-navigated total knee replacement

November 21, 2012
For many years, the use of computer-assisted navigation has been touted as improving the positioning, sizing and alignment of replacement knee joints, resulting in greater durability of joints and overall improvement in patient ...

Recommended for you

Drug therapy from lethal bacteria could reduce kidney transplant rejection

August 3, 2017
An experimental treatment derived from a potentially deadly microorganism may provide lifesaving help for kidney transplant patients, according to an international study led by investigators at Cedars-Sinai.

Exploring the potential of human echolocation

June 25, 2017
People who are visually impaired will often use a cane to feel out their surroundings. With training and practice, people can learn to use the pitch, loudness and timbre of echoes from the cane or other sounds to navigate ...

Team eradicates hepatitis C in 10 patients following lifesaving transplants from infected donors

April 30, 2017
Ten patients at Penn Medicine have been cured of the Hepatitis C virus (HCV) following lifesaving kidney transplants from deceased donors who were infected with the disease. The findings point to new strategies for increasing ...

'bench to bedside to bench': Scientists call for closer basic-clinical collaborations

March 24, 2017
In the era of genome sequencing, it's time to update the old "bench-to-bedside" shorthand for how basic research discoveries inform clinical practice, researchers from The Jackson Laboratory (JAX), National Human Genome Research ...

The ethics of tracking athletes' biometric data

January 18, 2017
(Medical Xpress)—Whether it is a FitBit or a heart rate monitor, biometric technologies have become household devices. Professional sports leagues use some of the most technologically advanced biodata tracking systems to ...

Financial ties between researchers and drug industry linked to positive trial results

January 18, 2017
Financial ties between researchers and companies that make the drugs they are studying are independently associated with positive trial results, suggesting bias in the evidence base, concludes a study published by The BMJ ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.