Every year, roughly two million people worldwide have a surgeon slide a tiny camera into their knee, trim a flap of torn cartilage, and send them home with instructions to ice and elevate. The procedure, called arthroscopic partial meniscectomy (APM), has been a staple of orthopedic medicine for decades. Now, a landmark clinical trial that followed patients for a full 10 years has delivered a verdict that is difficult to argue with: the surgery does not work for the most common type of meniscus tear, and it may leave the joint worse off than doing nothing at all.
The 10-year results, published in the New England Journal of Medicine, come from the Finnish FIDELITY trial, one of the only sham-surgery-controlled studies ever conducted on a major orthopedic procedure. Researchers are calling it a textbook case of “medical reversal,” the uncomfortable moment when rigorous evidence proves that a widely accepted treatment never actually helped.
What the trial actually tested
The FIDELITY trial, led by orthopedic researchers Teppo L.N. Järvinen and Raine Sihvonen at the University of Helsinki, enrolled adults with degenerative medial meniscus tears who did not yet have established osteoarthritis visible on X-rays. This is the patient profile that accounts for the vast majority of APM procedures: middle-aged or older adults whose cartilage has worn down gradually rather than torn in a single traumatic event.
Participants were randomly assigned to receive either a real arthroscopic partial meniscectomy or a meticulously designed placebo procedure. In the sham group, surgeons made the same skin incisions, manipulated the knee in the same way, and kept the patient in the operating room for the same amount of time. The only difference was that no cartilage was actually removed. Neither the patients nor the researchers evaluating their outcomes knew who had received the real operation. The trial was preregistered on ClinicalTrials.gov (NCT00549172), with its long-term follow-up planned from the outset.
The original short-term results, reported in 2013, showed no advantage for real surgery over the sham. A peer-reviewed two-year follow-up confirmed the pattern was not a short-lived fluke. And now, at the 10-year mark, the conclusion has not budged: there was no meaningful difference in pain, physical function, or knee-related quality of life between patients who had the real surgery and those who had the placebo.
The case against surgery keeps getting stronger
The FIDELITY trial does not stand alone. Two other major pieces of evidence point in the same direction.
The OMEX trial, an independent Norwegian randomized study, compared APM head-to-head with a structured exercise therapy program for degenerative meniscal tears and followed patients for 10 years. The result: patients who exercised instead of having surgery reported comparable levels of pain and function. On some measures, including quadriceps strength, the exercise group actually came out ahead. The trial found no signal that skipping surgery led to worse deterioration down the road.
A 2023 individual participant data meta-analysis published in The BMJ went further. By pooling data from 605 randomized patients across multiple trials, the researchers tested whether any identifiable subgroup benefited from APM. They examined age, baseline pain severity, the presence of mechanical symptoms like knee locking, and radiographic findings. Across every subgroup, no consistent or clinically important advantage for surgery emerged. That finding directly undercuts the most common justification surgeons offer for continuing to recommend the procedure: the belief that certain patients, especially those with locking or catching, are different.
Järvinen and Sihvonen have been blunt in their public commentary. They describe APM for degenerative tears not merely as unnecessary but as a procedure that carries real risks, including higher reoperation rates and the potential for accelerated osteoarthritis, without delivering compensating benefits.
What the evidence does not settle
The FIDELITY trial was designed to answer a specific question about a specific patient population, and several important gaps remain.
The trial excluded patients with acute traumatic tears, the kind that happen when a young athlete plants a foot and twists. It also excluded people who already had significant osteoarthritis. Whether APM has value for those groups is a separate question that this body of research does not directly address. Surgeons who still advocate for the procedure in select cases often point to clearly unstable or bucket-handle tears as a distinct category, and they may be right, but the evidence supporting surgery even in those scenarios is far less rigorous than the evidence now stacked against it for degenerative tears.
The mechanism by which APM may worsen knee health over time also remains incompletely understood. The leading hypothesis is straightforward: removing meniscal tissue changes how forces distribute across the joint, concentrating stress on the remaining cartilage and accelerating its breakdown. But confirming this would require dedicated imaging substudies that have not yet been published from the FIDELITY cohort. For now, the clinical data suggest a trajectory toward harm, even if the biological pathway has not been fully mapped.
The financial picture is similarly incomplete. APM is estimated to generate billions of dollars in annual healthcare spending globally, but no formal cost-effectiveness analysis tied to the FIDELITY or OMEX results has been published. The economic argument for shifting away from surgery is intuitive, but it currently rests on estimates rather than trial-linked modeling.
Perhaps the most consequential uncertainty is how quickly medical practice will actually change. As of June 2026, no major orthopedic society has issued updated clinical practice guidelines in direct response to the 10-year findings. Some regional guidelines had already begun recommending restraint based on earlier evidence, but the gap between what the research shows and what happens in operating rooms has historically been wide and slow to close. How quickly insurers adjust coverage policies will also shape the pace of change.
Why this evidence is so hard to dismiss
Sham-controlled surgical trials are exceptionally rare. They are expensive, logistically demanding, and ethically complex. Most surgical procedures are adopted based on observational data or comparisons to non-surgical treatment, which leaves open the possibility that the placebo effect of surgery itself, the anesthesia, the incisions, the post-operative attention, accounts for whatever improvement patients report. By mimicking every aspect of real surgery except the actual cartilage removal, the FIDELITY trial isolated the specific effect of meniscectomy from the broader experience of undergoing an operation. That design makes its negative finding unusually powerful.
The consistency of the result across three time points, from months to two years to a full decade, closes the door on the most common counterargument: that benefits might emerge with longer follow-up. They did not. And the convergence of evidence from a sham-controlled trial, an active-comparator trial against exercise, and a pooled meta-analysis examining subgroups elevates this from a single negative study to what methodologists call a robust medical reversal. The burden of proof has shifted. It now falls on those who would continue to offer APM for degenerative tears to demonstrate, with equally rigorous evidence, that exceptions to the rule exist.
What this means if your doctor recommends knee surgery
For patients, the practical takeaway is both sobering and genuinely encouraging. A widely promoted operation that once seemed like an obvious fix for a painful knee has not survived careful testing. But the same body of research shows that structured exercise, guided rehabilitation, and symptom-based care can deliver comparable outcomes without the risks, costs, or recovery time of surgery.
That does not mean every meniscus tear should be ignored. Acute traumatic tears, especially those causing a locked knee that physically cannot straighten, remain a different clinical scenario. But for the far more common degenerative tear, the kind that shows up on an MRI in a 50-year-old with a sore knee, the most evidence-based path as of mid-2026 is to start with physical therapy and exercise, not an operating room.
If a surgeon recommends arthroscopic partial meniscectomy for a degenerative tear, patients now have strong grounds to ask pointed questions: What evidence supports surgery over structured exercise for my specific situation? Has the recommendation accounted for the FIDELITY and OMEX trial results? And what are the risks that surgery could accelerate joint deterioration rather than prevent it? The research does not guarantee that every patient will do well without surgery. But it does guarantee that the old assumption, that trimming the torn cartilage is a safe and effective default, no longer holds up.
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*This article was researched with the help of AI, with human editors creating the final content.
