- Jeffrey Peng MD
- Mar 8
- 5 min read
Updated: Mar 18
By Dr. Jeffrey Peng, MD · Published March 08, 2026 · 8 min read
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A landmark randomized controlled trial published in the New England Journal of Medicine challenged one of the most common assumptions in orthopedic surgery: that patients with bone-on-bone knee arthritis inevitably need a knee replacement. The researchers took 100 patients who had been evaluated by an orthopedic surgeon and deemed eligible for total knee replacement, then randomly assigned half of them to skip the surgery entirely. What happened next may change how you think about treating severe knee osteoarthritis — because three out of four patients who skipped surgery never ended up needing it.
What Did the NEJM Knee Replacement Study Find?
The study enrolled 100 patients in Denmark with moderate-to-severe knee osteoarthritis. Every patient had been evaluated by an orthopedic surgeon and was considered a candidate for total knee replacement. These were not mild or borderline cases — these were patients whom a surgeon had looked at and said, "You qualify for surgery."
The researchers randomly divided them into two groups. The first group received a total knee replacement followed by 12 weeks of supervised non-surgical treatment. The second group received only the 12-week non-surgical program — no surgery at all. Both groups were then followed for 12 months.
As expected, the surgical group did show greater overall improvement in pain and function scores. That is not the surprising finding. The remarkable outcome was what happened in the group that did not receive surgery.
How Many Patients Avoided Knee Replacement Without Surgery?
Out of the 50 patients assigned to non-surgical treatment only, 37 of them — 74 percent — never ended up needing a knee replacement during the 12-month follow-up period. Their pain improved, their function improved, and they achieved these results without going through a major surgical procedure.
This is a critical finding for anyone who has been told they need a knee replacement. It demonstrates that a structured, evidence-based non-surgical approach can produce meaningful improvements for the majority of patients — even those with advanced osteoarthritis who have already been deemed surgical candidates.
What Are the Risks of Knee Replacement Surgery?
One aspect of this study that often gets overlooked is the difference in serious adverse events between the two groups. The knee replacement group experienced 24 serious adverse events, compared to just 6 in the non-surgical group — a four-fold difference. These complications included deep vein thrombosis, nerve damage, stiffness requiring manipulation under anesthesia, and wound complications.
When you weigh these complication numbers against the finding that three out of four patients in the non-surgical group did not need the procedure at all, it raises an important question about the order of operations. In my practice, I believe surgery should rarely be the first-line treatment for knee osteoarthritis — especially when a structured non-surgical program has not been attempted.
What Non-Surgical Treatments Worked for Knee Arthritis?
The non-surgical program in this trial was not simply telling patients to "go walk more." It was a structured, supervised 12-week protocol that combined four evidence-based components.
First, patients received individualized exercise therapy with a physical therapist, specifically neuromuscular training designed to improve how the muscles around the knee work together. Second, they received patient education so they understood what osteoarthritis actually is and what drives the pain. Third, dietary advice and weight management support were incorporated, because every pound of body weight translates to approximately four pounds of force across the knee joint with each step. Fourth, insoles and pain medication were used when appropriate.
This is an important distinction. No single intervention was the magic bullet. It was the combination of evidence-based treatments delivered together in a systematic, supervised way that produced these results.
Do Non-Surgical Results Last Long Term?
A reasonable question is whether these improvements hold up over time. The same research group published a five-year follow-up study in BMJ Open examining patients with knee osteoarthritis who were not initially eligible for knee replacement. Most patients experienced lasting, clinically meaningful improvements regardless of which treatment strategy they started with. Approximately two out of three never required a knee replacement during the entire five-year follow-up period.
These long-term findings reinforce the message that non-surgical treatment is not just a temporary fix. For many patients, it provides durable relief that can delay or even eliminate the need for surgery altogether.
Should You Get a Knee Replacement?
Knee replacements can be life-changing for the right patient at the right time. The goal here is not to discourage anyone from pursuing surgery when it is truly needed. However, the evidence from this study — published in the most prestigious medical journal in the world — tells us that surgery should not be the first option for most people. A structured non-surgical program should come first.
Here is what concerns me as a physician: most patients who are told they need a knee replacement have never gone through a structured non-surgical program like the one used in this study. They receive an X-ray, are told it looks bad, and are referred directly to a surgeon. But this research demonstrates that when patients are given the right non-surgical treatment first, the majority do not need the surgery at all.
What to Do If You Have Been Told You Need a Knee Replacement
If you or someone you care about has been told they need a knee replacement, consider these steps before committing to surgery. Ask your doctor whether you have tried a supervised exercise and rehabilitation program — not stretches found online, but a structured program with a physical therapist. Discuss weight management, because even modest weight loss can significantly reduce the forces on your knee. Consider getting a second opinion from a sports medicine physician who can help you understand your non-surgical options. And remember that your X-ray does not determine your destiny. Pain and function are what matter, and those can change dramatically with the right treatment.
References
1. Skou ST, Roos EM, Laursen MB, et al. A Randomized, Controlled Trial of Total Knee Replacement. N Engl J Med. 2015;373(17):1597-1606. doi:10.1056/NEJMoa1505467
2. Larsen JB, Roos EM, Laursen M, et al. Five-year follow-up of patients with knee osteoarthritis not eligible for total knee replacement: results from a randomised trial. BMJ Open. 2022;12(11):e060169. doi:10.1136/bmjopen-2021-060169
Medical Disclaimer: This content is for educational purposes only and does not substitute for the medical advice of a physician. Always consult your healthcare provider before beginning any new treatment program. The information presented reflects the opinion of Dr. Jeffrey Peng and does not represent the views of his employers or affiliated hospital systems.