Could Using GLP-1s Delay or Cancel Knee Replacement Surgery?
- Jennifer Hardy
- Jun 2
- 5 min read
For years, my future seemed pretty straightforward. At some point, I was going to need a knee replacement. I have bone-on-bone osteoarthritis in both knees. Every orthopedic appointment seemed to end with the same conversation. The surgery wasn't necessarily needed today, but it was coming eventually. The only question was when.
To further complicate and concern my health, my mother passed away after her second knee replacement surgery. Blood clots entered her lungs the day after surgery, and there was no way to save her. Needless to say, I am not thrilled about ever going under that knife.
Then I lost more than 150 pounds on Zepbound. The weight came off. The inflammation decreased. Moving became easier. Stairs stopped feeling like a personal attack. And for the first time in years, I started wondering if that "inevitable" knee replacement might not be quite so inevitable after all.
It turns out I'm not the only one asking that question.
New research suggests GLP-1 medications like Zepbound (tirzepatide) and Wegovy (semaglutide) may do more than help people lose weight. They may also reduce the long-term likelihood of needing knee replacement surgery.
Why Knee Replacements Are So Common for People With Obesity
More than 300 million people worldwide live with osteoarthritis, making it one of the most common causes of chronic pain and disability.
While age plays a role, excess body weight puts enormous stress on the knee joints. Every additional pound of body weight translates into roughly four pounds of pressure on the knees during daily activities.
That means carrying an extra 100 pounds can place hundreds of additional pounds of force on already damaged joints every time you walk, climb stairs, or stand up from a chair.
For many patients, that wear and tear eventually leads to total knee replacement surgery. Meanwhile, studies are showing new hope. While we've explored the Joint Gut Axis here on the website before, there's another silver lining starting to form.
The Study That Has Researchers Paying Attention
A new analysis published in the journal Regional Anesthesia & Pain Medicine examined medical records from adults diagnosed with knee osteoarthritis between 2010 and 2024.
Researchers compared patients taking GLP-1 receptor agonists with similar patients who were not using the medications.
The data included more than 42,000 patients who used GLP-1 medications for at least one year and nearly 31,000 patients who used them for three years. What they found was hard to ignore. Patients taking GLP-1 medications consistently had lower rates of knee replacement surgery than comparable patients who weren't taking the drugs.
The biggest reductions were seen among people who used newer medications like semaglutide and tirzepatide and who remained on treatment longer.
After three years of treatment with semaglutide or tirzepatide, patients showed nearly a 5% lower cumulative risk of knee replacement surgery at the eight-year follow-up point.
Is It Just the Weight Loss?
That's the obvious question. After all, losing a significant amount of weight reduces stress on the knees. That alone could explain some of the improvement. But researchers think there may be more happening.
Emerging evidence suggests GLP-1 medications may help reduce inflammation throughout the body. Some early research also indicates they could have protective effects on cartilage and joint tissues.
The study authors noted that the benefits observed were consistent with both anti-inflammatory and pain-relieving effects, raising the possibility that these medications may influence osteoarthritis progression itself rather than simply helping patients lose weight.
That doesn't prove causation. The study was observational, meaning researchers identified associations rather than direct cause-and-effect relationships.
Still, it's enough to get attention. In addition, as a Zepbound user, I can honestly say that my inflammation and knee pain decreased substantially in the first two months. That was long before I lost any meaningful amount of weight. In fact, I think the reason I shed so quickly was that the edema was draining from my entire inflamed body.
What Orthopedic Surgeons Are Seeing
Many orthopedic surgeons have noticed something interesting in their own practices.
Patients who lose substantial weight often report less knee pain, better mobility, and improved quality of life. Some decide to postpone surgery. Others find that their symptoms become manageable enough that surgery moves much lower on the priority list.
That doesn't mean damaged cartilage suddenly regrows. Bone-on-bone arthritis doesn't magically disappear. But if symptoms improve enough that daily life becomes manageable, patients may choose to delay surgery for years. For younger patients, especially, that can matter.
The concern isn't necessarily the surgery itself. It's that artificial joints have a lifespan. If someone receives a replacement in their 40s or early 50s, there's a greater chance they'll eventually need a revision surgery later in life.
As a result, many orthopedic surgeons prefer to delay replacement as long as symptoms remain manageable.
The problem is that "manageable" can be a moving target when every step hurts.
For people caught in that middle ground, anything that safely reduces pain and improves function becomes incredibly valuable.
Could GLP-1s Become Part of Osteoarthritis Treatment?
We're not there yet. No GLP-1 medication is currently approved specifically to treat osteoarthritis or prevent knee replacement surgery.
Researchers are also careful to point out the limitations of the new study. Factors such as exercise habits, arthritis severity, physical function, and whether patients actually took the prescribed medications weren't fully captured.
"If confirmed in prospective trials, these associations could shift treatment paradigms toward integrating metabolic health as a core component of joint preservation and inform guidelines on GLP-1 [receptor agonist] use in patients at risk of surgical progression."
But if future clinical trials confirm these findings, experts believe GLP-1 medications could become an important part of joint preservation strategies for people with obesity and metabolic disease.
In other words, orthopedic care and metabolic health may become much more connected than they've traditionally been. However, GLP-1s are infants on the pharmaceutical scene, and there are still a lot of research dots to connect.
Have You Experienced Knee Pain Relief on GLP-1s?
I'm curious if there are more people like me, who used to walk with a cane or need a rolling chair to get around, and now can speed walk with the best of them.
If you already have severe knee osteoarthritis, a GLP-1 medication isn't a guarantee that you'll avoid surgery forever. For some people, knee replacement will still be the best option.
But growing evidence suggests these medications may help delay that decision, reduce symptoms, and potentially lower the likelihood of surgery altogether. As someone who once viewed knee replacement as an unavoidable chapter waiting in the wings, that's encouraging news.
The surgery may still be in my future. Then again, maybe not. For the first time in a long time, that's starting to feel like a real possibility.
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