By the time 64-year-old Laura Milson decided to undergo total knee replacement after 12 years of suffering from arthritis, even a short walk to the office printer was a struggle.
After her surgery last August at the Rothman Institute at Thomas Jefferson University in Philadelphia, Ms. Milson spent a week in rehabilitation and says she hasn’t stopped walking since. “My son says to me, ‘You have to slow down,’ and I say, ‘No, I have to catch up!,’ ” she said. “It’s a whole different life.”
For Ms. Milson, who lives in Shrewsbury, Pa., replacing the joint in her right knee came with a surprising bonus: a 20-pound weight loss in two months. “I joked with my doctor, ‘I think you put a diet chip in my knee,’ ” she said. “The weight just sort of came off.”
Now she has joined Weight Watchers to drop a few extra pounds and is training for a three-day breast cancer walk in October.
For years surgeons have boasted of the pain relief and improved quality of life that often follow knee replacement. But now new research suggests that for some patients, knee replacement surgery can actually save their lives.
In a sweeping study of Medicare records, researchers from Philadelphia and Menlo Park, Calif., examined the effects of joint replacement among nearly 135,000 patients with new diagnoses of osteoarthritis of the knee from 1997 to 2009. About 54,000 opted for knee replacement; 81,000 did not.
Three years after diagnosis, the knee replacement patients had an 11 percent lower risk of heart failure. And after seven years, their risk of dying for any reason was 50 percent lower.
The study, presented this month at the annual meeting of the American Academy of Orthopedic Surgeons, was financed with a grant from a knee replacement manufacturer. It was not randomized, so it may be that these patients were healthier and more active to start with.
Still, the researchers did try to control for differences in age and overall health. And the findings are consistent with large studies of knee replacement and mortality in Scandinavia. Given the big numbers in the study and the size of the effect, the data strongly suggest that knee replacement may lead to improvements in health and longevity.
The theory behind knee replacement, said the study’s lead author, Scott Lovald, senior associate at Exponent, a scientific consulting firm in Menlo Park, is that it improves quality of life. “At the end of the day, we’re trying to figure out if quantity of life increases as well,” he added, noting that the team was conducting a similar review of Medicare data on the long-term benefits of hip replacement surgery.
The founder of the Rothman Institute, Dr. Richard H. Rothman, who has performed 25,000 joint replacement surgeries in his career, urged caution in interpreting data that are not randomized and controlled. Not every patient with knee arthritis is a candidate for joint replacement surgery, he said.
“People can tolerate a lot of knee disability for reasons we don’t totally understand,” he went on, adding, “If the pain is acceptable, you live with it; if it’s not acceptable, we’ll operate on you.”
Dr. Rothman said that whether patients experience better health after surgery depends on motivation — how motivated they were to stay fit before surgery and how motivated they are now to become more active.
“For the motivated patient, it allows them to walk through that portal and become better conditioned and lose weight,” he said. “It’s not a weight-reduction program. It’s a potential avenue to improve your level of fitness, weight, cardiovascular health and mental health.”
Edward Moore, a 94-year-old retired chemist in Woodbury, N.J., underwent knee replacement three years ago after pain began limiting his activity. Given his age, his own daughter had worried that the recovery would be too difficult. But Dr. Rothman agreed he was healthy enough for the procedure.
“I didn’t do much mulling about it,” Mr. Moore said. “It just seemed like the knee would be hampering me for the rest of my life, and that sounded like a bad idea.”
Mr. Moore said he had an uneventful recovery, and in September, two days after his 94th birthday, he took his wind surfer to Lakes Bay near Atlantic City. “I got up on the board, and I sailed,” he said.
William Mills, 63, of Philadelphia, had been suffering for about four years with severe pain in both knees when he opted for double knee replacement in 2006. He said his activity had dropped off, and while he could still play golf, he could no longer walk the course. Even going to a restaurant had become a burden if he couldn’t find a parking space nearby.
“I think one of the things people don’t understand about knees is how bad it is,” said Mr. Mills, a bank executive. “It changes everything. I couldn’t walk two city blocks. It was just slowly but surely changing my life where I was unable to really enjoy things.”
But while the rehabilitation of both knees was “the hardest thing I’ve ever done in my life,” he has no regrets. Six months after surgery he took part in a 250-mile bike ride in Germany. He has made a few compromises — he no longer skis, and plays doubles tennis instead of singles — but he says he now rarely thinks about his knees.
“Before surgery, I felt like I was 10 or 15 years older than I was,” he said. “Now I probably feel like I’m 10 or 15 years younger than I am.
“I can understand why people might live longer, because you want to. You really feel good again.”
One morning, a well-meaning swimming buddy called out for all in the Y locker room to hear: “I can’t believe Jane Brody doesn’t do yoga!”
She was right: I didn’t do yoga and, not knowing what it might offer me, I was loath to try it. I also feared that the meteoric growth of yoga had outpaced the training of quality teachers able to protect my aging body parts.
Now, it seems, my thinking and schedule may be due for a change. After reading my colleague William J. Broad’s new book, “The Science of Yoga,” and observing a class at my local Y, I see there may be a lot more to this centuries-old activity, more to its benefits and its risks, than I had ever imagined.
And if the science recounted in this book is correct (knowing Mr. Broad, I have every reason to think it is), my creaky joints and muscles may reap some important rewards from an individualized yoga prescription. I’m especially concerned about my back, which is riddled with narrowed vertebral spaces and prone to spasms and sciatica.
Mr. Broad said decades of yoga has helped protect his back from excruciating pain initially caused by a ruptured disc. Yet in 2007, even he succumbed to a yoga-induced back injury as he was coming out of a pose called the Extended Side Angle.
“Recovery took weeks,” he wrote. “But the humbling experience gave me a deeper appreciation for yoga safety.”
Not all yoga poses are beneficial or safe for everyone, and enthusiasts are hard put to know whether the teacher and class they select are more likely to help than to hurt them.
What I need is yoga therapy, and I can only hope to benefit from it if the teacher is well-qualified. And therein lies the rub.
As I learned from Mr. Broad’s book, “the United States has no regulatory body for yoga therapy. The field is, on the whole, completely unlicensed and unregulated. There is no such thing as a Registered Yoga Therapist. Applicants for registration usually face no requirements to establish their education credentials, to pass national exams, or to show other evidence of expert proficiency. Registration, in short, bears no comparison to the rigorous world of health-care certification.”
Anyone who chooses to can hang out a shingle and call himself a yoga therapist. Licensing requirements exist for beauticians and hairdressers, but not for yoga therapists.
The Yoga Alliance, a national organization for yoga in the United States, fills in this gap with specific training standards that, if met, earn the title registered yoga teacher. The standards involve either 200 or 500 hours of instruction and supervised practice, with specialized training for children’s and prenatal yoga.
To be sure, the yoga world is rife with true believers, many of whom bombarded Mr. Broad with complaints about an article he wrote in The New York Times Magazine last month chronicling a raft of devastating yoga-induced injuries. But he was also deluged with dozens of personal injury stories that included strokes and ruptured discs.
Among them was that of a 39-year-old man who said in an e-mail that he’d “always been very active,” having “skied, boxed, climbed, surfed, etc.” The man began practicing yoga in 2000 and said he reveled in the meditative aspects of it, in contrast to his more “brutal sports.”
Then, in 2010, he enrolled in a new class and developed “severe spinal stenosis” with debilitating back spasms when the teacher “literally forced me into maintaining an extremely painful Downward Dog.” This is a classic pose in which hands and feet are flat on the floor, knees are straight (though not locked) and the body is bent at the waist at a right angle.
In a more serious injury resulting from the Downward Dog, a woman in Washington, D.C. suffered a spinal cord infarction, a blockage that caused sudden leg paralysis. She has since regained only partial use of her legs.
Mr. Broad concluded, based on his research, that the benefits of yoga “unquestionably outweigh the risks. Still, yoga makes sense only if done intelligently so as to limit the degree of personal danger.”
Thus, it is critical to choose your class and teacher carefully. Grace Grochowski, a registered yoga teacher at my local Y who has been teaching for 20 years, recommends that prospective students ask about an instructor’s formal training, tell him or her what they hope to get from the discipline, and report any injury, ache or health condition that might affect their participation.
The teacher should be willing to suggest changes in the moves you attempt or even say that the class may not be right for you.
“A good teacher listens and makes appropriate suggestions,” Ms. Grochowski said. Though her popular class is large, she regularly walks among the participants, correcting and modifying their poses and suggesting alternatives.
Most important, Randi Baker, one of her students, told me, is to “never go for the burn. If something hurts, don’t do it.”
Many of the oft-touted virtues of yoga have yet to be established in well-designed clinical trials, Mr. Broad wrote, and some popular claims have been shown to be bogus, like the belief that yoga breathing suffuses the body with extra oxygen or that it revs up metabolism and can foster weight loss. (Yoga actually slows metabolism, though its relaxing effect may reduce stress-related eating.)
Good scientific studies, including many supported by the National Center for Complementary and Alternative Medicine, an arm of the National Institutes of Health, have demonstrated that regular yoga practice can improve cardiovascular risk factors like elevated blood pressure, blood sugar, bloodcholesterol and clot-inducing fibrinogen, and it can raise blood levels of protective antioxidants.
Yoga was shown to improve balance in elderly women and thus may reduce their risk of falls, a leading cause of injury-related death in older people. And, I was pleased to learn, perhaps by enhancing blood flow and the production of growth factors, yoga can counteract the deterioration of spinal discs, a plague of millions of Americans, young and old.
Possibly through its stimulation of the vagus nerve, yoga appears to counter inflammation throughout the body, and may reduce the effects of diseases likelupus and rheumatoid arthritis. And by relieving physical and mental stress, which can erode the tips of DNA, which are called telomeres and program cell death, yoga may slow biological aging and prolong life.
A more immediate benefit, to which Mr. Broad devotes an entire chapter, is yoga’s apparent ability to revitalize a person’s sex life by producing surges in sex hormones and the brain waves associated with sexual arousal. Just don’t try to act on this stimulation in class.