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Just 11 extra pounds can ruin healthy knees


Gaining even a small amount of weight may not only damage your knees — leading to pain, stiffness and mobility issues — but also increase your odds of needing knee replacement surgery, according to research presented last month at the International Congress on Obesity.

Among study participants, a gain of just 11 pounds made total knee replacement 34 percent more likely for women and 25 percent more likely for men. The finding stems from the researchers’ review of two studies, involving some 264,000 people.

Overall, however, they reviewed data from 23 studies, focusing on the relationship between weight gain and knee osteoarthritis and finding that, as weight increased, participants’ symptoms and radiographic scans of their knees indicated worsening osteoarthritis.

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The Centers for Disease Control and Prevention cites osteoarthritis as the most common type of arthritis; more than 32 million American adults have the degenerative joint disease. It can damage any joint, but the knees are one of the most commonly affected joints.

Osteoarthritis develops when the cartilage that acts as a cushion between the bones in a joint breaks down or wears away, giving the condition its “wear and tear” disease nickname. This leaves the bones in the joint to rub together, causing pain, stiffness and movement issues.

No cure exists for knee osteoarthritis, but treatment may include medication, physical therapy and activity modifications. If that proves to be insufficient, knee replacement surgery may be an option, with arthritic parts of the joint removed and replaced with metal, plastic or ceramic parts.

First performed in the 1960s, the surgery has become fairly common, according to the American Academy of Orthopaedic Surgeons, with more than 750,000 knee replacements done each year in the United States. Based on their findings, the researchers suggest that preventing weight gain — which they say is easier than losing weight — should reduce the risk for knee osteoarthritis and the number of needed knee replacements.

This article is part of The Post’s “Big Number” series, which takes a brief look at the statistical aspect of health issues. Additional information and relevant research are available through the hyperlinks.