Finnish study finds popular knee surgery offers no long-term benefit

The 10-year follow-up of Finland’s FIDELITY trial found that arthroscopic partial meniscectomy, a common knee procedure that trims damaged meniscus tissue, did not deliver clinically relevant improvement over sham surgery and was linked to more progression of knee osteoarthritis.

The placebo-surgery controlled randomized study enrolled adults ages 35 to 65 with knee symptoms, MRI-verified degenerative medial meniscus tears and no clinical signs of knee osteoarthritis at the outset. Across the trial, 146 participants were randomized, and the long-term results showed no meaningful difference in patient-reported symptoms or function between the surgery group and the sham group. Knee muscle strength also did not show a clinically relevant advantage for the operation.

The finding lands hard because arthroscopic partial meniscectomy has long been used as a routine fix for meniscus tears. In the new analysis, the authors said the result may represent a medical reversal and questioned the biological assumption that pain on the inner side of the knee is caused by a meniscus tear that surgery can repair. Their conclusion does not apply to acute traumatic meniscus injuries, which were not the population studied.

The long-term data reinforce a broader shift already visible in the medical literature. In 2017, The BMJ issued a strong recommendation against arthroscopy for nearly all patients with degenerative knee disease, including people with or without imaging evidence of osteoarthritis, mechanical symptoms or sudden symptom onset. A 2015 BMJ systematic review and meta-analysis found only a very small short-term pain benefit from arthroscopy, no significant improvement in function and harms that included deep vein thrombosis, pulmonary embolism, infection and death.

Practice in Finland has already moved sharply in the same direction. Registry research covering 1998 to 2018 found arthroscopy incidence fell 74% overall, arthroscopy for osteoarthritis dropped 91% and arthroscopic partial meniscectomy for degenerative meniscal tears fell 77%. The trend suggests the long-running evidence base has already changed how Finnish doctors treat these injuries, even as many patients elsewhere still face surgery as a standard option.

For patients weighing whether to proceed now, the central question is no longer whether the operation is popular. It is whether a procedure that failed against sham surgery over 10 years and showed more osteoarthritis progression should still be presented as a default answer for degenerative knee pain.