If you're battling knee pain but the joint still has full range of motion, hold off on surgery – even if an MRI reveals a meniscus tear. A new study in the 'New England Journal of Medicine' finds that one of the most common knee surgeries performed in the U.S. doesn't repair rips in the knee-cushioning cartilage any better than a fake operation.

Researchers in Finland recruited 146 people plagued with knee pain caused by wear and tear to the meniscus, rather than by a recent injury. Half of the participants underwent arthroscopic partial meniscectomy, while the other half received sham surgery. Participants in neither group knew which procedure was performed on them. After one year, the doctors saw no measurable difference in how well the two groups' knees healed.

This study adds to the mounting evidence that surgeons may be performing way more knee surgeries than necessary.

"Meniscus tears don't always warrant surgery," says Dr. Edward Laskowski, co-director of the Mayo Clinic Sports Medicine Center in Rochester, Minnesota. "Over the past few years, we've realized that you have to treat the patient's symptoms, not the MRI. If the scan shows that you have a meniscus tear, but you can still use your knee and don't hear a loud popping sound when moving it, oftentimes it can be treated with physical therapy and rest rather than surgery."

There are still situations for which surgery remains your best bet. "If your knee is locked or you can't extend it, or if you've tried physical therapy and rest and still experience pain – and you have a documented meniscus tear – then you might be a great candidate for surgery," says Laskowski. Since knee pain has so many different causes beyond just meniscus tears, such as ligament damage, osteoarthritis, or simple overuse, talk with your doc if you have chronic aching or swelling. "For any knee pain that's interfering with your everyday life, go see a musculoskeletal specialist who focuses on knees, who can develop a treatment plan for you," Laskowski says.