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Older adults who opt for a total knee replacement – arthroplasty – have a better quality of life compared to those who choose nonsurgical treatments for advanced osteoarthritis.
That’s one of the findings of a recent study published in the Archives of Internal Medicine. Researcher Elena Losina, PhD, and her colleagues from Brigham and Women’s Hospital and the Boston University School of Public Health, determined that total knee arthroplasty (TKA) in the Medicare population is a cost-effective procedure overall, regardless of a patient’s risk for complications as a result of surgery.
Researchers also found that the surgery is more cost effective when done at a high-volume medical center – one that does more than 200 procedures a year – than when done at a low-volume center – one that does fewer than 25 procedures a year. Outcomes were better at high- and medium-(26-200) volume centers than at those that do fewer knee replacements.
Nearly 500,000 total knee replacements were performed in the United States in 2005 at a cost of more than $11 billion. The study authors note that total knee arthroplasty is an “effective procedure that relieves pain and improves functional status in patients with end-stage knee osteoarthritis.”
A dramatic growth in the use of TKA over the next two decades is projected, primarily due to people living longer, as well as the growing obesity epidemic. While the procedure has been shown to relieve pain and improve the quality of life for those with advanced osteoarthritis, the study authors note that no research had been done in the United States on the cost-effectiveness of the surgery or on the influence of hospital volume and patient risk.
Osteoarthritis, a degenerative bone disease, is the most common form of arthritis. The condition comes from wear and tear of the knee over time, causing painful bone-on-bone contact. While there is no cure, there are some nonsurgical treatments designed to reduce pain. But when those conservative treatments fail to relieve knee pain and restore motion, the surgical approach of replacing the knee may be a treatment option. The procedure typically involves replacing damaged bone and cartilage with metal alloy and polyethylene (plastic) components.
The study was done by looking at Medicare claims for patients who had a total knee replacement in 2000, as well as cost, outcomes and quality-of-life data from national and multinational sources. A computer simulator model looked at costs and outcomes for four treatment options for patients with advanced osteoarthritis: no TKA, TKA at a low-volume hospital, TKA at a medium-volume facility, and TKA at a high-volume hospital.
TKA in the overall Medicare population(average age of 74) with advanced osteoarthritis was associated with a projected quality-adjusted life expectancy of 7.957 years compared with 6.822 years for patients not having TKA. Lifetime medical costs varied from $37,100 per person without TKA to $57,900 per person having TKA. The incremental cost effectiveness ratio for TKA was $18,300 per quality-of-life year.
The procedure appeared to be cost effective regardless of a patient’s risk for surgical complications such as infection, pulmonary embolism or pneumonia; the incremental cost effectiveness estimates ranged from $9,700 per quality-adjusted life year for those in the low risk group to $28,100 for high-risk patients. Also, the procedure was cost-effective regardless of whether it was performed at a low-, medium- or high-volume center. For high-risk patients, however, total knee replacement at a center that did few procedures wound up costing more and producing worse outcomes than having the procedure done at either a high- or medium-volume center. Overall, the procedure was most cost effective when done at high-volume centers.
In an editorial in the same issue of Archives of Internal Medicine, Stephen Lyman, PhD, and his colleagues note that the study only looked at Medicare data to define hospital volumes. While an estimated 60 percent of TKAs done in the United States are on Medicare patients, the proportion varies greatly by geographic region. Hence some hospitals may be classified as having a lower volume based on their Medicare population, when, in fact, they perform more procedures in total when including non-Medicare patients.
The study findings are also sensitive to the researchers’ estimate of quality-of-life years, and if that estimate was too optimistic, the actual cost-effectiveness findings may not be as favorable as indicated. The findings are also not based on data from randomized controlled studies, depending instead on a before-and-after design that assesses a patient’s status both prior to and after treatment. However, the editorial notes that it would be unethical to deny the procedure to some patients participating in a random design when 90 percent of patients having TKA report higher functional ability and less pain.
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This study validates what I’ve always believed: A knee replacement can improve a person’s overall quality of life. It’s a very cost-effective way of restoring a person to a more active life. I see it all the time – people young and old who were on heavy pain medication and unable to walk can now contribute to and be a part of society.
“Best of all, we see every day how this surgical procedure is helping people return to a more normal life where they can walk without pain.”
A knee replacement for someone who has been disabled because of osteoarthritis can restore that person’s ability to get a job or do volunteer work or whatever they want to do. Those who were homebound can get out and exercise. This improves their health by helping them lose weight and reduce the risk for diabetes and cardiovascular disease.
Sadly, I see a number of people who put off this procedure out of fear of surgery. Then, when they are ready for it, they have a medical condition that makes them no longer a candidate for surgery and they wind up in a wheelchair. Younger people with knee pain are often dissuaded from seeing an orthopaedic surgeon. In the past, there were fewer options for younger people, but now we can do partial knee replacements instead of waiting till the knee osteoarthritis becomes debilitating bone on bone to do a total knee replacement.
The study also validates what we have found to be true at our UK Orthopaedic Surgery Program at UK Good Samaritan Hospital. By moving the bulk of our knee and hip replacement surgeries to UK Good Samaritan, we are able to perform the procedures more cost effectively, with better outcomes than most other programs. We are considered a high-volume center with more than 600 knee replacements performed by five orthopaedic surgeons. In fact, we are the busiest hip and knee replacement facility in central Kentucky and the second busiest in the state (second only to a Louisville facility). I do more than 450 hip and knee replacements a year at Good Samaritan – most are knee replacements. We have a dedicated team of physicians and staff whose only focus is on joint replacement surgery. As a high-volume center, the whole system is geared to streamlining the process, doing things more quickly and precisely to benefit the patient. We have dedicated operating rooms and all patients go to the same inpatient nursing unit. Patients attend a presurgery class so that they and their loved ones know what to expect. Prompt physical and occupational therapy while on the nursing unit helps get patients up and walking, with assistance, by the time they go home three to four days after surgery. All of this results in lower costs, as the Medicare study demonstrated.
Other ways of reducing the cost of knee replacements include the discounts high-volume centers get from the companies that make the artificial knees, as well as keeping infection rates as low as possible. One infection can add as much as $50,000 to the cost of a patient’s hospital stay. We do everything we can to prevent infection; as a result, I have a zero infection rate with my patients, and our program overall has a very low rate compared with most other programs.
We’ve made tremendous strides at improving the procedure itself, and the types of artificial knees available that are made to fit men and women of all sizes. There is even a knee now for people with metal allergies. Best of all, we see every day how this surgical procedure is helping people return to a more normal life where they can walk without pain.
UK Orthopaedic and Sports Medicine physicians seek to improve the quality of life for patients who suffer from debilitating injuries or chronic bone and joint problems, restoring them to a healthy level of activity. UK’s orthopaedic specialists and fellowship trained surgeons are world-renowned for developing and implementing state-of-the-art techniques to diagnose, treat, research, and educate patients about bone and joint disorders. For an appointment and information, call 859-323-5533, or visit
Dr. Giordani is an orthopaedic surgeon at UK HealthCare and assistant professor of surgery at the UK College of Medicine.
Each issue of Advances & Insights summarizes an important piece of medical news, accompanied by commentary from a UK expert.
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