Adjunct Professor Teppo Jarvinen of the University of Helsinki and the Helsinki University Central Hospital and Raine Sihvonen of Hatanpaa Hospital in Tampere said the most common diagnosis of the knee that requires treatment is a tear in the meniscus -- the shock-absorbing cartilage of the knee. Most of the treated meniscal tears are degenerative -- caused by aging, not trauma.
The treatment involves the partial removal of the meniscus through keyhole surgery via arthroscopy; a minimally invasive surgical procedure using an arthroscope, a type of endoscope inserted into the joint via a small incision.
The study involved 146 participants, ages 35 to 65. The study participants were randomly assigned to undergo either an arthroscopic partial meniscectomy or placebo surgery where the procedure was simulated.
No one involved in the study -- patients, medical staff or the researchers -- knew if the patient was in the meniscectomy or placebo group.
A year after the procedure, of the patients who underwent the partial meniscectomy, 93 percent would choose the same treatment, while 96 percent of those in the placebo group would choose the same.
"By ceasing the procedures, which have proven ineffective, we would avoid performing 10,000 useless surgeries every year in Finland alone," Sihvonen said. "The corresponding figure for the United States is at least 500,000 surgeries."
The study was published in the New England Journal of Medicine.