Common Knee Surgery Found Ineffective in Long-Term Study; May Worsen Symptoms Over Time

A Closer Look at the Common Knee Surgery That May Not Work

For decades, if you went to a doctor with knee pain from a torn meniscus—that C-shaped piece of cartilage that cushions your knee—you were very likely told you needed surgery. The procedure, called a partial meniscectomy, involves trimming away the torn part of the meniscus. It is one of the most common orthopedic surgeries in the world. But a major new study from Finland suggests that for many patients, this surgery may be useless. Even worse, it might actually make your knee worse over time.

The study, called the Finnish Degenerative Meniscal Lesion Study (FIDELITY), followed patients for 10 years. It found that people who had the real surgery did not have better outcomes than those who received a fake, or “sham,” surgery. In fact, after a decade, the surgery group reported more knee symptoms, poorer knee function, greater progression of osteoarthritis, and a higher chance of needing another knee surgery. This is what researchers call a “medical reversal”—a treatment once believed to be helpful is now shown to be ineffective or even harmful.

If you or someone you know has been recommended for this surgery, this news is important. It means you may have options that are safer and just as effective. It also raises big questions about why some common medical treatments continue to be used even when evidence shows they do not work.

What Is a Partial Meniscectomy and Who Gets It?

A partial meniscectomy is a surgical procedure where a surgeon removes a small piece of a torn meniscus. The meniscus acts like a shock absorber in your knee. As people age, the meniscus can wear down and develop degenerative tears—these are not caused by a sudden injury but by years of wear and tear. Many people over 40 have these tears without even knowing it. They may have no pain or limited movement.

For years, the logic seemed simple: if the meniscus is torn and causing pain, trim the torn part, and the pain will go away. This idea made biological sense. But as the FIDELITY study shows, biological logic does not always match real-world results. The pain in degenerative knee conditions is often linked to aging and overall joint degeneration, not just the tear itself. Removing a piece of cartilage does not fix the underlying problem.

How This Affects You: What the Study Really Means

If you are experiencing knee pain, especially on the inner side, you might be told you have a medial meniscus tear. This study suggests that rushing into surgery may not be the best choice. The FIDELITY study included 146 participants with degenerative meniscal tears. They were randomly assigned to receive either partial meniscectomy or a sham surgery—a procedure where patients were put under anesthesia and given small incisions, but no actual trimming was done. Neither the patients nor the evaluators knew who got which procedure. This is the gold standard for testing whether a treatment truly works.

After 10 years, more than 90% of the original participants completed the final follow-up. The results were clear: the surgery group did not benefit. They reported more knee symptoms and worse knee function. They also showed greater progression of osteoarthritis—the “wear and tear” arthritis that can lead to joint replacement. And they were more likely to need additional knee surgery down the road.

Lead investigator Teppo Järvinen, a professor at the University of Helsinki, explained that the findings suggest this may be an example of “medical reversal.” He noted that for nearly a decade, independent, non-orthopedic organizations that create clinical guidelines have recommended stopping the procedure. Yet groups like the American Academy of Orthopedic Surgeons (AAOS) and the British Association for Surgery of the Knee (BASK) have continued to support it. Järvinen said this shows how hard it is to give up treatments that do not work.

What Experts Say About the Results

Raine Sihvonen, a specialist in orthopedics and traumatology and the other lead investigator of the FIDELITY study, explained the core problem. He said the surgery is based on the idea that pain on the inside of the knee comes from a medial meniscus tear that can be treated surgically. He added that this kind of reasoning—assuming something works because it seems biologically logical—is still very common in medicine. However, in this case, the assumption does not hold up under careful testing.

Dr. Roope Kalske, a doctoral researcher and specialist in orthopedics and traumatology, noted that several randomized studies have already shown that partial meniscectomy does not improve patients’ symptoms or function in the short term (1 to 2 years) or medium term (5 years). Despite this, the procedure remains widely used in many countries. Changing clinical practice has been slow, even with growing evidence against the surgery.

Earlier registry and observational studies had already raised warnings about possible downsides of this surgery. These include a higher chance of needing a joint replacement, called arthroplasty, and a possible increase in complications after the procedure. But observational data alone cannot prove cause and effect. The FIDELITY study, with its sham surgery control group, provides stronger evidence.

Practical Takeaways: What You Can Do

If you are dealing with knee pain and have been told you need a partial meniscectomy, here are some steps you can take:

• Ask about non-surgical options first. Physical therapy, strengthening exercises, weight management, and anti-inflammatory medications are often just as effective as surgery for degenerative meniscal tears. Many people improve with these treatments alone.
• Get a second opinion. Not all doctors agree on the best approach. Seek advice from a specialist who is aware of the latest research, including the FIDELITY study.
• Understand the risks. Surgery is not without risks. This study shows that patients who had the real surgery had more knee symptoms, worse function, more osteoarthritis, and a higher chance of needing another surgery after 10 years.
• Be patient. Knee pain from degeneration can take time to improve. Many people find that symptoms get better on their own or with conservative care over several months.
• Talk to your doctor about the sham surgery study. Knowing that a placebo procedure worked just as well as the real surgery can help you make a more informed decision.

Why This Matters for the Future of Medicine

The FIDELITY study is a powerful example of why we need rigorous testing for common medical procedures. It was carried out across five hospitals in Finland, showing strong teamwork and patient dedication. Research manager Pirjo Toivonen praised the collaboration and the commitment of the patients. She noted that the study is a good example of smooth collaboration between hospitals and researchers.

The study also highlights a troubling pattern in medicine: once a treatment becomes standard, it is very hard to stop using it, even when evidence shows it does not work. Järvinen pointed out that for nearly a decade, many independent, non-orthopedic organizations that create clinical guidelines have recommended stopping the procedure. Yet groups like the American Academy of Orthopedic Surgeons (AAOS) and the British Association for Surgery of the Knee (BASK) have continued to support it.

For patients, this means you need to be an active participant in your own healthcare. Do not assume that a common treatment is the right one. Ask questions. Seek out the latest evidence. And remember that sometimes, the best treatment is no treatment at all—or a treatment that focuses on strengthening your body rather than cutting it.

The Bottom Line

Partial meniscectomy is a common knee surgery that has been performed for decades. But the FIDELITY study, which followed patients for 10 years, shows that it does not improve symptoms or function compared to a sham procedure. In fact, patients who had the real surgery ended up with worse outcomes, including more pain, poorer knee function, more osteoarthritis, and a higher chance of needing additional surgery.

If you are considering this surgery, take the time to explore non-surgical options first. Talk to your doctor about the risks and benefits. And remember that the best treatment for a degenerative meniscal tear may be patience, physical therapy, and time—not an operating room.