Knee osteoarthritis means that your knee hurts and your doctor does not know the cause. With aging, a person wears away the shock-absorbing cartilage in the knees, which increases risk for pain and swelling. Often people with knee osteoarthritis have perfectly normal MRIs of their knee cartilage, and people with MRI evidence of torn cartilage often have no pain or swelling. Many studies present overwhelming evidence that surgery for torn knee cartilage (torn meniscus) does not reduce knee pain or swelling in the long run. Indeed, studies show that exercise is more effective than operations (arthroscopic partial meniscectomy) in treating people with knee pain and degenerative meniscal tears (British Medical Journal, July 20, 2016). An editorial in the same issue of BMJ states, “The surgery is a highly questionable practice without supporting evidence of even moderate quality . . . the latest nail into what should be a sealing coffin.” Surgery has not been shown to be more effective than exercise in treating knee osteoarthritis (N Engl J Med, 2013;368:1675-84) and arthroscopic partial meniscectomy is not more effective than sham placebo surgery for a degenerative meniscal tear (N Engl J Med, 2013;369:2515-24)….