Brisbane – The overweight that overweight people put on their knees is the number one risk factor for osteoarthritis of the knee.
According to the study, obese people need ANZ Journal of Surgery (2022; DOI: 10.1111 / ans.17689) not only use knee replacements more often. Surgery is necessary for them at a young age.
More than half of Australians who need a knee replacement for osteoarthritis of the knee are obese. The proportion is significantly higher than in the general population (57.7% vs. 37.4%), which illustrates the importance of the obesity risk factor, which is particularly pronounced in osteoarthritis of the knee, as both knee joints have to carry and move almost the entire body weight.
Surgeon Christopher Wall of Toowoomba Hospital, part of the University of Queensland in Brisbane, has noticed that an unusually large number of younger people need a new knee joint. A comparison of the “Australian Orthopedic Association” patient registry with the “National Health Survey” confirmed this impression.
The proportion of obese patients was particularly high in the 45-54 age group. Women were affected more often than men. In the case of grade 1 obesity (BMI 30 to 35), Wall calculates that women are 7.5 times more likely to have a knee replacement. In men, the risk was increased by a factor of 3.2.
For grade 2 obesity (BMI 35 to 40), the relative risk was 12.2 in women and 5.4 in men. Women aged 45 to 54 years with grade 3 obesity (BMI over 40) required total knee arthroplasty 24.9 times more often than women of normal weight of the same age. In men with grade 3 obesity, the risk was increased by a factor of 7.0.
In contrast, the risk in men and women with grade 3 obesity aged 75 to 84 years was only slightly increased (relative risk 2.2 and 1.5 compared to normal weight people).
The median age at surgery was 71.3 years for normal weight women. For stage 1 obesity, surgery was necessary at 68.5 years, for stage 2 obesity at 66.5 years, and for stage 3 obesity at 64.1 years. Therefore, women with grade 3 obesity required joint replacement 7.2 years earlier.
For men, the difference was 7.3 years: for grade 3 obesity, the operation was performed at 63.7 years, compared with 71.0 years of normal weight.
British orthopedists came to a similar conclusion. Nicholas Clement and colleagues investigated in Journal of Orthopedic Research (2020; DOI: 10.1002 / jor.24460) for 3 degrees of obesity earlier knee replacement period of 4.7 years, 6.7 years and 10.5 years (for both sexes together). There was an earlier time point for hip replacement surgery of 3.1 years, 5.2 years and 7.4 years for 3 degrees of obesity. © rme / aerzteblatt.de