Patient selection for bilateral total knee replacement needs improvement

September 29, 2012
"The take home message of this paper is that we are fighting an uphill battle, because people are getting sicker, despite us attempting to limit risk by choosing younger people to do these procedures in," said Dr. Memtsoudis. "We have to start thinking of other interventions other than patient selection that we can implement in order to reduce these complications." Credit: Hospital for Special Surgery

Because there are more risks with having a total knee replacement in both legs at the same time than having a knee replacement in one leg, doctors in recent years have been selecting younger and healthier patients for the bilateral procedure. Now a new study by researchers at Hospital for Special Surgery has revealed that although patients are younger and healthier than those undergoing only one-sided surgery, they are becoming sicker and some complication rates have risen.

"Although we are selecting younger people, we can't ignore the fact that the population in general is getting sicker," said Stavros Memtsoudis, M.D., Ph.D., director of Critical Care Services at Hospital for Special Surgery (HSS) in , who led the study. "Many of the complications that we studied didn't decrease over time as you would expect with younger patients and better health care, and some of the complications even increased." The study is published online ahead of print in the journal Clinical Orthopaedics and Related Research.

Rising levels of obesity appear to be driving the complication rates, as well as the increase in the utilization of total knee replacements. Obesity puts extra on joints and bones and can cause premature .

To conduct their research into trends regarding bilateral total knee replacements, researchers at HSS turned to the Nationwide Inpatient Survey, sponsored by the Agency for Healthcare Research and Quality (AHRQ). This is the largest inpatient database available in the United States that includes information on patients of all ages. It collects data from about 20% of all hospitalizations in the U.S. The study investigators identified 258,524 bilateral performed between 1999 and 2008. The number of annual bilateral procedures increased by 75%. In 1999, bilateral procedures accounted for 3.7% of all operations and in 2008, they accounted for 6% of the operations.

The average age of patients undergoing bilateral knee replacement decreased by 2.5 years from 1999 to 2008. As the years marched on, patients presented with higher rates of comorbidities, including renal failure, neurologic disease, liver disease, diabetes, and chronic obstructive pulmonary disease. Obesity increased by 131% during the study period. The only comorbidity that decreased was congestive heart failure.

Over the time period studied, the researchers identified a 3% increase in pneumonia, a 6% increase in pulmonary embolism, and a 3% increase in nonmyocardial infarction cardiac complications.

"The take home message of this paper is that we are fighting an uphill battle, because people are getting sicker, despite us attempting to limit risk by choosing younger people to do these procedures in," said Dr. Memtsoudis. "We have to start thinking of other interventions other than patient selection that we can implement in order to reduce these complications."

On a positive note, the investigators also found that absolute in-hospital mortality rates decreased at an average rate of 10% per year. The researchers attribute this decrease to advances in medicine and increased use of telemetry and observation in the last 10 to 15 years. "With advances in medicine and monitoring, we have been able to counteract this extreme event of mortality. If you get a complication and it is not recognized, you may die from it," said Dr. Memtsoudis. "If you observe people more thoroughly, you may not be able to prevent the complication, but you may be able to prevent a mortal event resulting from it."

The researchers also identified a cost shifting landscape. Patients stayed in the hospital an average of five days after their procedure in 1999 and an average of four days in 2008, but the proportion of discharges to a home or customary residence without home health care decreased at an average rate of 5.5% per year.

"Before this study, we were under the assumption that patient complications were steadily decreasing after bilateral knee arthroplasty, because of better patient selection and improvements in medical care," said Dr. Memtsoudis. "Now we understand that the picture is more complex. Patients being selected for the procedure may be getting younger, but they are not getting healthier and maybe that is why we don't see a drastic drop in complications."

Before embarking on a bilateral knee replacement, he said, patients should "critically look at themselves and talk to their physicians about how their health status plays into the choice of surgery."

More work is needed to identify ways to prevent complications in patients undergoing bilateral knee replacement and a recent conference sponsored by the Hospital for Special Surgery is aiming to do just that. The Consensus Conference on the Creation of Guidelines for Bilateral Knee Arthroplasty involved 40 experts from 16 institutions. The guidelines coming out of this conference, which are expected to be published within the next six months, address issues such as determining the appropriate workup and management for a patient undergoing bilateral knee replacement, and how long should wait between procedures if a patient undergoes two operations.

Explore further: Study identifies patients at increased risk after bilateral knee replacement surgery

Related Stories

Study identifies patients at increased risk after bilateral knee replacement surgery

July 14, 2011
A new study by researchers at Hospital for Special Surgery has identified patients who are at a higher risk of morbidity and mortality when undergoing knee replacement surgery in both legs at the same time. The study found ...

Growing popularity of hip and knee replacement surgery places extra burden on critical care services

June 5, 2012
Roughly 3 percent of patients who undergo total hip and knee replacement surgery require critical care services before they are discharged from the hospital, according to an analysis of roughly half a million patients. The ...

Joint replacement surgery riskier at hospitals with low surgical volume

June 7, 2011
Patients who undergo elective total hip or total knee arthroplasty at hospitals with lower surgical volume had a higher risk of venous thromboembolism and mortality following the procedure. The complications following joint ...

Knee replacement surgery incidence soars in those over age 50

January 17, 2012
Researchers in Finland found that annual cumulative incidences of partial and total knee arthroplasty, commonly known as knee replacement surgery, rose rapidly over a 27-year period among 30 to 59 year-olds in that country, ...

Recommended for you

Smoking raises risk of aneurysm recurrence after endovascular treatment

August 17, 2017
In a new study, researchers report people who have experienced an aneurysm have another reason to quit smoking.

Study adds to evidence that most prescribed opioid pills go unused

August 2, 2017
In a review of half a dozen published studies in which patients self-reported use of opioids prescribed to them after surgery, researchers at Johns Hopkins report that a substantial majority of patients used only some or ...

Engineers harness the power of 3-D printing to help train surgeons, shorten surgery times

August 2, 2017
A team of engineers and pediatric orthopedic surgeons are using 3D printing to help train surgeons and shorten surgeries for the most common hip disorder found in children ages 9 to 16. In a recent study, researchers showed ...

World's first child hand transplant a 'success'

July 19, 2017
The first child in the world to undergo a double hand transplant is now able to write, feed and dress himself, doctors said Tuesday, declaring the ground-breaking operation a success after 18 months.

Knee surgery—have we been doing it wrong?

July 18, 2017
A team of University at Buffalo medical doctors have published a study that challenges a surgical practice used for decades during arthroscopic knee surgery.

New tools help surgeons find liver tumors, not nick blood vessels

July 17, 2017
The liver is a particularly squishy, slippery organ, prone to shifting both deadly tumors and life-preserving blood vessels by inches between the time they're discovered on a CT scan and when the patient is lying on an operating ...

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.