A comprehensive long-term study from Finland is adding weight to mounting evidence that one of the world’s most common knee procedures may offer little benefit to many patients who receive it.
The research, following patients for up to 10 years, examined arthroscopic partial meniscectomy—a minimally invasive surgery where surgeons trim damaged cartilage in the knee. The procedure is performed hundreds of thousands of times annually in the United States alone.
The Finnish study, known as the FIDELITY trial (Finnish Degenerative Meniscal Lesion Study), originally compared the surgery against a sham procedure in patients with degenerative meniscal tears. The long-term follow-up results, published in the British Medical Journal in 2022, showed no meaningful difference in pain or function between patients who received real surgery versus those who underwent a placebo procedure.
“What we found was that patients who had the real surgery didn’t fare any better than those who had the sham surgery, even after 10 years,” said Dr. Raine Sihvonen, an orthopedic surgeon at Helsinki University Hospital and lead author of the study.
The trial’s design was particularly rigorous. In the sham surgery group, patients received anesthesia and surgeons made the same small incisions used in real arthroscopy. They inserted a camera into the knee joint and performed all the typical surgical steps—except actually removing any meniscal tissue.
Neither patients nor most of their subsequent care providers knew which procedure they had received, eliminating potential bias in reporting outcomes.
The study tracked 146 patients aged 35 to 65 who had knee pain and MRI-confirmed degenerative meniscal tears but no significant arthritis. After randomization, 70 patients received arthroscopic partial meniscectomy while 76 underwent the sham procedure.
At the 10-year mark, researchers found no clinically meaningful differences between groups in knee pain, function, or quality of life measures. Both groups showed similar improvement from their baseline symptoms, suggesting that factors other than the surgery itself—such as natural healing, physical therapy, or time—contributed to patients feeling better.
The findings align with several other major studies questioning the surgery’s effectiveness for degenerative tears, which are different from acute traumatic injuries. A 2013 study in the New England Journal of Medicine found similar results, as did research published in the BMJ in 2016.
Dr. Teppo Järvinen, a professor of orthopedics at the University of Helsinki and senior author of the FIDELITY trial, noted that degenerative meniscal tears are often part of normal aging rather than injury requiring surgical repair.
“These tears are frequently found in people without any knee symptoms,” Järvinen said. “The assumption that removing torn meniscal tissue will eliminate pain may be fundamentally flawed in many cases.”
The research has significant implications given the procedure’s prevalence. According to the American Academy of Orthopaedic Surgeons, approximately 700,000 arthroscopic meniscal surgeries are performed annually in the United States. Healthcare utilization studies suggest the global number reaches into the millions.
However, medical organizations have been slow to change recommendations despite accumulating evidence. The American Academy of Orthopaedic Surgeons updated its clinical guidelines in 2017 to recommend against the surgery for most patients with degenerative tears, particularly those with arthritis. But implementation of these guidelines in clinical practice has been inconsistent.
Some orthopedic surgeons argue that careful patient selection remains important, noting that younger patients with specific types of tears may still benefit from surgery.
“The key is distinguishing between degenerative tears that are part of normal wear and tear versus traumatic tears in younger, active patients,” said Dr. Kurt Spindler, an orthopedic surgeon at the Cleveland Clinic who was not involved in the Finnish study.
The economic implications are substantial. Estimates suggest that arthroscopic knee procedures generate billions of dollars in healthcare spending annually in the United States alone.
Patient advocates say the research underscores the importance of trying conservative treatments first, including physical therapy, activity modification, and anti-inflammatory medications.
“Many patients can achieve good outcomes without surgery,” said Sihvonen. “The challenge is identifying which patients truly need surgical intervention versus those who will do just as well with non-operative treatment.”
The Finnish researchers acknowledged limitations in their study, including its single-center design and the exclusion of patients with large, displaced meniscal tears that clearly require surgery.
Future research is focusing on better ways to predict which patients are most likely to benefit from meniscal surgery, potentially through improved imaging techniques or identification of specific tear patterns that respond well to surgical treatment.
For now, the growing body of evidence suggests that many patients with degenerative meniscal tears may achieve similar outcomes through less invasive approaches, challenging decades of conventional surgical wisdom.