Obesity Increases Risk of Total Knee Replacement

Have you ever had to drag a heavy suitcase through the airport?  Or move a box of books? The heavier your load is, the harder it is to move. The further you have to go, the more tired you get. In an extreme case, if your load were too heavy, you could potentially injure yourself moving it. There are some loads you simply can’t safely lift.

Our knee joints are much like a person carrying a heavy load. For every 10 pounds of weight we carry, the knee carries 15 to 20 pounds of pressure. Fortunately, our knees are designed to carry the weight of our bodies, so this doesn’t usually cause a problem.

Gaining excess weight can force our knees to carry more weight than they are designed to carry. Over time our knees can become damaged. The cartilage that cushions the joint wears away and our bones rub against one another at the joint. This can be extremely painful and lead, eventually, to total knee replacement surgery. Obesity and the Relative Risk of Knee Replacement Surgery in Patients With Knee Osteoarthritis: A Prospective Cohort Study – PubMed (nih.gov)

The younger someone is when they have obesity, the younger the age at which they are likely to need knee replacement surgery. Knee replacement only lasts between 15 and 25 years. This means that younger patients are more likely to need not one, but two, knee replacement surgeries in their life. In addition, patients with obesity are more likely to need a second knee replacement sooner, as the extra weight puts more strain on the artificial joints and also increases the risk of surgical complications. Degree of Obesity Relates to Risk of Post-Operative Complications in Hip and Knee Arthroplasty – Consult QD (clevelandclinic.org)

Because of the risk of complications from obesity, surgeons sometimes recommend, or even require, certain levels of weight loss before surgery.