The risk of complications from bilateral knee replacement surgery is rising, according to researchers who say even younger, healthier patients — who were thought to be less susceptible to problems – are getting sick and seeing a spike in complication rates.
Because there are more risks involved with having a total knee replacement in both legs at the same time, doctors have been selecting younger candidates for the bilateral procedure. But the results of a study at the Hospital for Special Surgery in New York City now has doctors questioning that practice.
“Although we are selecting younger people, we can’t ignore the fact that the population in general is getting sicker,” said Stavros Memtsoudis, MD, director of Critical Care Services at the Hospital for Special Surgery. “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.”
Investigators found that although the average age of patients dropped by 2.5 years, the rate of ailments, such as renal failure, neurologic disease, diabetes and chronic obstructive pulmonary disease climbed. Obesity in patients also soared by 131 percent.
Researchers say that the rise of obesity appears to be driving the complication rates, as well as a 75 percent annual jump in the number of patients opting to have the bilateral procedure. In 1999, the procedure accounted for 3.7% of all knee replacement operations. In 2008, they accounted for 6% of the operations.
Over that same period of time, investigators discovered a 3% increase in pneumonia, a 6% increase in pulmonary embolism, and a 3% increase in non-myocardial 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 Memtsoudis. “We have to start thinking of other interventions other than patient selection that we can implement in order to reduce these complications.”
But not all the news was bad. Researchers noted that in-hospital mortality rates decreased at an average rate of 10% per year, which they attribute to advances in health care and the increased use of telemetry and observation.
“With advances in medicine and monitoring, we have been able to counteract this extreme event of mortality,” said 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.”
Before embarking on a bilateral knee replacement, Memtsoudis says patients should take a critical look at themselves and talk to their physician.
“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 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.”
The results of the study are published in the journal Clinical Orthopaedics and Related Research.