Obesity is making knee replacements more common at a younger age

Our joints are constructed from living tissues. However, at some point they sometimes cannot repair themselves in time and people start suffering so much that they need a joint replacement surgery. Obviously, this problem is more common among old people, but, as scientists at The University of Queensland have found, there is something that is making knee replacement surgeries much earlier.

Knee replacement surgery is not a simple procedure and it can sometimes take up to 6 months till the patient is recovered. Image credit: BruceBlaus via Wikimedia (CC BY-SA 4.0)

It is not that joints are simply wearing down  – joint replacement is usually needed because of diseases like osteoarthritis. Just that these surgeries are usually not needed for younger people. Scientists analysed data of 56, 217 patients who underwent a knee replacement for osteoarthritis and found that 57.7% of them were obese. Furthermore, obesity seems to be lowering the age for knee replacement surgeries, especially among women.

It is not surprising that obesity has terrible health effects. Knees are under a lot of pressure, which eventually causes damage. Scientists found that 55–64 year old women who are obsese are up to 17.3 times more likely to undergo a knee replacement surgery than women who are of a healthy weight. In the same age group of men this number is 5.8 times. And, as mentioned above, obese people are typically significantly younger when they need new knees.

Osteoarthritis (OA) is actually the most common form of arthritis. It occurs when cartilage cannot repair quick enough and the joint tissues become permanently damaged. Good thing is that it is possible to reduce your risk of OA and its complications. Dr Chris Wall, lead investigator of the study, said: “Modest weight loss has been found to effectively reduce knee OA symptoms, and obese patients who maintained a 10% body weight loss experienced significant improvement in pain and function”.

In Australia, where this study was conducted, the situation is quite poor. One third of adults there are obese. People with the highest BMI ratio in this study were seven years younger on average when they had a knee replacement, compared to normal weight individuals. This means that in the future Australia will have a huge problem with how common knee replacements are going to be.

Knee replacement is a fairly complex surgery. Knees are obviously very important joints and replacing them with artificial parts requires cutting and drilling bone, attaching metal parts, aligning everything – it is invasive and painful. It takes around 6 weeks till the patient is able to partake in moderate physical activity while swelling might take half a year to subside entirely. Therefore, if you’re obese, you should really look for ways to lose weight.

Source: University of Queensland