Arthroscopic surgery on the meniscus is the most common orthopedic procedure in the United States, performed, the study said, about 700,000 times a year at an estimated cost of $4 billion.

“Those who do research have been gradually showing that this popular operation is not of very much value,” said Dr. David Felson, a professor of medicine and epidemiology at Boston University. This study “provides information beautifully about whether the surgery that the orthopedist thinks he or she is doing is accomplishing anything. I think often the answer is no.”

The new research builds on a groundbreaking 2002 Texas study, showing that patients receiving arthroscopy for knee osteoarthritis fared no better than those receiving sham surgery. A 2008 Canadian study found that patients undergoing surgery for knee arthritis did no better than those having physical therapy and taking medication. Now many surgeons have stopped operating on patients with only knee arthritis.

Earlier this year, a study at seven American hospitals found that patients with meniscal tears and osteoarthritis did not experience greater improvement with surgery than those receiving physical therapy, although after six months, one-third of the physical therapy group sought surgery. (Their surgical results were not reported.)

“Take 100 people with knee pain; a very high percentage have a meniscal tear,” said Dr. Kenneth Fine, an orthopedic surgeon who also teaches at George Washington University. “People love concreteness: ‘There’s a tear, you know. You have to take care of the tear.’ I tell them, ‘No. 1, I’m not so sure the meniscal tear is causing your pain, and No. 2, even if it is, I’m not sure the surgery’s going to take care of it.”

Dr. Fine added: “Yours truly has a meniscal tear. It just causes pain. I’m not having any mechanical symptoms; my knees are not locking. So I’m not going to let anybody operate.”

I could not straighten my injured left leg because of a "flap" on the torn meniscus. My doctor told me I needed surgery to correct the flap. Unbelievably, six visits later the pain was completely gone and I could straighten the leg my doctor told me would be impossible without surgery. I have become an advocate for Matt Whitehead and Oregon Exercise Therapy (OET). Do yourself a favor; check out OET before you consider surgery. Some simple exercises might help you avoid the cost and recovery time of medical intervention.

He (Dr. Fine) likened the recent studies to attempts to educate people that “it’s not really good to take antibiotics for the common cold. There’s a lot of pressure to operate. Financial, obviously. But also, if a primary care doctor keeps sending me patients who are complaining of knee pain and I keep not operating on them, then the primary care doctor is going to stop sending me patients.”

You know the old adage, an apple a day keeps the doctor away? Well, my next guest might add to that. How about a jog a day keeps the doctor away, or a set of pull-ups? His new book is a prescription pad for a variety of ailments from anxiety and depression to heart disease, diabetes, low libido, arthritis, even cancer. But what's different about this medical book is that there are no drugs recommended, no trips to the pharmacy.

Instead, he recommends tailored exercise regimens for exactly what ails you, whether it's strength training for menopause or yoga for anxiety, because he says exercise is a wonder drug that can cure a whole variety of conditions, maybe even help you fight cancer. And for all you sitting at your desk right now — yeah, you — he offers a few tips on how to build activity into your day, even if you have a sedentary office job.

Dr. Jordan Metzl is the author of "The Exercise Cure: A Doctor's All-Natural, No-Pill Prescription For Better Health & Longer Life." He's also a sports medicine doctor at the Hospital for Special Surgery here in New York. Welcome to SCIENCE FRIDAY.

Outward knee alignment increases arthritis risk, finds NIH-funded study. Existing arthritis worsens when poorly aligned joints bear increased stress.

The study authors found that the higher risk occurred among those with an outward-facing alignment—knees relatively far apart and ankles closer together. Known as varus alignment, the knee configuration resembles bowleggedness, but is not as extreme.

Osteoarthritis results from the deterioration of cartilage, the hard, slippery material that cushions the ends of bone at the joints.

The researchers also confirmed earlier findings that for people who have arthritis, varus alignment as well its opposite, the valgus, or inner facing, alignment contribute to worsening of the condition on the side of the knee bearing more stress.

Nancy Shinowara, Ph.D., “Future research may lead to new ways to reduce the stress that the condition places on knees and, in so doing, prevent osteoarthritis or lessen its severity.”

"This E-cise is designed to allow flexion and extension of the leg, rather than rotation through adduction and abduction (side-to-side movement).”

"Keep in mind that the body is a unit and that the body is linked functionally from head to toe. The anterior tilt of the pelvis is caused by the strong, tight hip flexor muscles and puts excessive arching into the low back. The more a person walks with the tight hip flexors, the more they pull down on the spine and exacerbate the problem. To relieve the tension on the spine, the upper back rounds – taking the shoulders forward – and the head tilts downward. To relieve the tension in the hips, the femurs externally rotate, taking the knees and feet outward. This is a formula for pain up and down the body."

"It is something that really can help your balance. I had some lower back problems a few years ago and once I started to do the yoga, it has helped them go away for now. Of course we can stretch but stretching only goes so far."

"No, no injuries -- just not suiting up." 

“It's my whole back. My neck and my back. The good thing is, it's not my first time having back issues, so I'll be all right...I keep an eye on it."