"When people expect too much, they lose more and more functions and cannot exercise or be active, leaving them exposed to weight gain, depression and other health problems," said lead researcher Hassan Ghomrawi, associate professor of Northwestern University surgery. Feinberg School of Medicine.
Also, the surgery may not be as successful, Ghomrawi said.
"There are several studies that have shown that patients who undergo surgery when their function is severely impaired can improve a lot, but their improvement is not yet average," Ghomrawi said. "They fall behind in optimal benefit."
On the other hand, the study also found that 25% of people who opt for knee surgery receive it too soon, run significant risks, including possible complications, while potentially incurring the cost of major surgery without obtaining an additional benefit. in mobility
"There are a million knee surgery procedures that occur in the United States every year," Ghomrawi said, "and 25% of them are premature. That's a lot of patients."
Because artificial knees wear out after about 20 years, early users also prepare for another knee replacement later in life, said Ghomrawi, which is generally a much harder surgery with a worse outcome than the original.
An objective algorithm
The study, published Monday in the Journal of Bone and Joint Surgery, followed more than 8,000 people with symptoms of knee osteoarthritis for up to eight years.
While other studies have looked at people who underwent the knife, it is believed that this study is the first to examine the opportunity of knee replacement among people who could benefit from the procedure, Ghomrawi said.
"There are 16 unique combinations that can be assigned according to age, knee stability and if the patient has mild, moderate, intense or intense pain," Ghomrawi said.
Knee stability is defined as the ability not only to bend, but also how "wavy" the knee is due to loose tendons, and also takes into account the sounds of clicking and grinding.
In addition, the measurement analyzes the severity of osteoarthritis on radiographs, "if it is bone on bone", as well as how many parts of the knee are affected: the femur (thigh bone), the tibia (tibia) and the patella (kneecap) ).
After factoring all these elements, Ghomrawi and his team assigned the patients in the study to three categories: on time: they underwent surgery within two years after the replacement became potentially appropriate; delayed: no surgery or surgery you waited until after those two years; and premature
The cost of premature surgery.
And then there is the growing popularity of surgery: the American Academy of Orthopedic Surgeons projects that knee replacements only in the US. UU. They will grow up to 189% over the next decade, for a projected 1.28 million procedures by 2030.
Can an objective algorithm work?
Not everyone believes that such an objective approach will succeed in the healthcare environment.
"I would say that this document analyzes the issue from the perspective of experts and not necessarily from the perspective of the patient," said Dr. Bart Ferket, assistant professor of population science and health policies at the Icahn School of Medicine at the Hospital Mount Sinai In New York.
"It's an attempt to objectify things that are subjective," said Mount Sinai orthopedic surgeon Dr. Edward Adler, who, like Ferket, was not involved in the study.
The pain, for example, is subjective and could interfere with the algorithm's ability to assess knee stability and pain levels reported by the patient.
"Some people will allow you to move your knee even though it hurts a lot," Adler said. "They can have a lot of pain, you wouldn't know. They work well."
"There are other people who have a little pain and everyone around them has to know." "So it's quite subjective as to how much you tolerate before your knee is replaced."
Ghomrawi agrees that there could be excellent subjective reasons why a person could decide to receive an early knee transplant instead of deciding to wait.
A scenario, he says, for a transplant at an earlier age, for example, could come from financial considerations. A candidate for surgery may choose to move forward, thinking: "I am the only financial support for my family; I maintain my functional level so that I can continue to be the support of my family."
Or maybe an older person has a very painful knee, "but they support it because they are taking care of their spouse," Ghomrawi said.
Objective or subjective, Adler said there should be a realistic assessment by each person of what a new knee can really achieve. If a person undergoes surgery before the onset of severe or significant pain, the patient may not see sufficient improvement.
"Knee replacements are not really made for tennis and running," he said, "they are made for long distances and daily activities.
"What God gave you is not necessarily the same as I can give you," Adler said, "if your goal is to be normal, it is difficult to get when the knee comes out of a box."