Hand Holding Painful Injured KneeA major 10-year study suggests a widely used knee surgery may do more harm than good. Credit: Shutterstock

A 10-year follow-up of the FIDELITY trial, which was controlled with placebo surgery, found that partial meniscectomy does not improve patients’ symptoms or function.

Partial meniscectomy, a procedure that trims a degenerated meniscus, is among the most frequently performed orthopedic surgeries worldwide. Although its use has dropped sharply in Finland in recent years, the operation is still widely used in many other countries.

A 10-year follow-up study found that partial meniscectomy did not improve symptoms or knee function when compared with sham surgery. In fact, patients who received partial meniscectomy had more symptoms, poorer function, greater progression of osteoarthritis, and a higher likelihood of later knee surgery than those who underwent sham surgery.

The Finnish Degenerative Meniscal Lesion Study (FIDELITY) is notable for both its design and its duration. It included a sham surgery control group and followed patients for 10 years. Participants with degenerative meniscal tears were randomized to receive either partial meniscectomy or sham surgery.

A common surgery faces reversal

Teppo Järvinen, Professor at the University of Helsinki and the principal investigator of the FIDELITY, emphasizes the broader importance of the findings:

“Our findings suggest that this may be an example of what is known as a medical reversal, where broadly used therapy proves ineffective or even harmful.”

“The surgery is based on the assumption that pain in the inside of the knee is caused by a medial meniscus tear, which can be treated surgically. Such reasoning – assumption based on biological credibility – is still very common in medicine but in this case, the assumption does not withstand critical examination. Based on current understanding, pain in various joints, such as the knee joint in this case, is related to degeneration brought about by aging,” says Raine Sihvonen, Specialist in Orthopaedics and Traumatology and the other principal investigator of the FIDELITY study.

Concerns about the adverse effects of surgery

Recent registry and observational studies have raised concerns that partial meniscectomy may cause harm. These data have linked the procedure with a risk of arthroplasty, or joint replacement surgery, and possibly a higher risk of postoperative complications. However, observational evidence is indirect by nature and cannot prove cause and effect.

“Several randomized studies have already demonstrated that partial meniscectomy has not improved patients’ symptoms or function in the short (1–2 years) or medium (5 years) term. Regardless, the procedure has remained widely used in many countries,” says Doctoral Researcher and Specialist in Orthopaedics and Traumatology, Dr. Roope Kalske.

“For nearly a decade, many independent, non-orthopedic organizations providing clinical guidelines have recommended that the procedure should be discontinued. Still, for example, the American Academy of Orthopaedic Surgeons (AAOS) and the British Association for Surgery of the Knee (BASK) have continued to endorse the surgery.

This effectively illustrates how difficult it is to give up inefficient therapies,” Järvinen sums up.

“The study conducted in five hospitals is an example of smooth multicenter collaboration, as well as the commitment of research patients to an interesting project. Of the original 146 participants, more than 90% took part in the final stage of the study,” says the research manager Pirjo Toivonen.

Reference: “Arthroscopic Partial Meniscectomy for Degenerative Tear — 10-Year Outcomes” by Roope Kalske, Raine Sihvonen, Mika Paavola, Antti Malmivaara, Ari Itälä, Antti Joukainen, Juha Kalske, Heikki Nurmi, Pirjo Toivonen, Niko Sillanpää, Tommi Kiekara, Aleksandra Turkiewicz, Martin Englund, Simo Taimela and Teppo L.N. Järvinen, 29 April 2026, New England Journal of Medicine.
DOI: 10.1056/NEJMc2516079

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