Jeff Stewart, 43, a house painter and former high school and college athlete, remembers the exact moment his hip gave out: Valentine's Day 2006.
"I bent down to paint something low. When I got up, my hip never stopped hurting until I woke up from surgery in January 2007," he said. The pain, due to an anatomical abnormality made worse by years of wear and tear, was so bad that sometimes all he could do was lie on his recliner and watch TV: "When you are in so much pain, your life is reduced to that."
But like a growing number of young, active people, Stewart eschewed the "gold standard" treatment - total hip replacement surgery - in favor of a new procedure that, propelled by aggressive marketing featuring pictures of vigorous, youngish athletes, is sweeping the United States: hip resurfacing.
The main claim for resurfacing is that it can preserve more of the thigh bone, making any subsequent surgery more feasible if the initial repair wears out.
Stewart, who paid $30,000 for the procedure and follow-up care because it was not then covered by insurance, is delighted with the results. He can once again "paint million-dollar houses by myself and jump up on roofs."
But many orthopedic surgeons, including the one who performed Stewart's surgery, Dr. Carl Talmo at New England Baptist Hospital, are worried about the rate at which doctors, most of whom are still on a steep learning curve for this technically demanding procedure, are jumping to do it. (Resurfacing is so new that statistics on the number of people who get it will not be available until next year, according to the American Academy of Orthopaedic Surgeons.)
"I'm encouraged, but I also harbor a healthy skepticism toward resurfacing," said Talmo, who added that Stewart was his first - carefully selected - patient. "There's tremendous potential for young, active adults," he said, "but we need to be cautious because there is also the potential for this to be overutilized in the wrong patients.
"Every objective study of hip resurfacing anywhere in the world demonstrates slightly higher failure rates in the first one to five years than total hip replacement," Talmo added.
In hip resurfacing, surgeons shave down the tip of the thigh bone, capping it with metal, and then scrape out the hip socket into which the cap fits and line the socket with metal. The surgery and recovery with resurfacing can take just as long as with the standard replacement operation, and it often requires a bigger incision.
Dr. Michael Millis, director of the adolescent and young adult hip unit at Children's Hospital Boston, put it more bluntly: "Resurfacing is very attractive because of its great stability. But it's a harder operation. There's more blood loss. And nobody has 20-year results."
Dr. Donald Reilly, an orthopedic sur geon at the Baptist, was blunter still. If a surgeon recommends hip resurfacing, he said, "Run away as fast as you can. Or limp out of that office. There is no advantage and many disadvantages. It won't give you anything more than a total hip replacement, and with some significant downsides."
Strong words, to be sure, especially given the longer use of resurfacing in Australia, Canada, the UK, and Belgium. Though resurfacing is now covered by insurance in this country, some patients still fly to Belgium and other nations where surgeons are more experienced and the operation may be cheaper.
In the United States, the first device, dubbed the "Birmingham hip," was approved by the US Food and Drug Administration only in May 2006. The FDA approved a second device, the Cormet, in July 2007.
More devices are in the pipeline, as manufacturers seek to capture a growing market: athletic, healthy baby boomers with strong bones but hips damaged by congenital abnormalities like Stewart's or osteoarthritis.
It is a tall order.
Normally, the hip joint is a smoothly functioning ball and socket, with the ball, the head of the thigh bone (femur), fitting snugly and painlessly into the socket, a cup-shaped bone of the pelvis called the acetabulum.
In total hip replacement surgery, which is performed nearly 300,000 times a year, according to the American Academy of Orthopaedic Surgeons, doctors cut off the head of the femur and insert a rod with a metal ball on top into the leg bone. They also remove bone from the pelvic "socket" and insert a plastic "cup" into which the metal ball fits.
Replacement surgery "works 98 percent of the time," said Reilly of the Baptist. The devices can be metal, ceramic, plastic, or a combination. But if, after 10 to 20 years, the patient needs the hip replaced again, the second surgery is more difficult because so much bone was removed the first time.
In other words, total hip replacement is fine for older people whose life expectancy more or less equals that of the hip replacement. But for young people like Stewart, who might need two or three revisions, resurfacing might make more sense.
"It's a weird argument - the idea that if you need a revision, the revision will be easier [with resurfacing] than with a full hip replacement, but if you're younger, this is realistic," said Dr. Sean Rockett, an orthopedic surgeon at Newton-Wellesley Hospital who does resurfacing, though less often than hip replacements.
Resurfacing involves removal of less bone from the femur, thus in theory making any subsequent revision more feasible, although this might be somewhat offset by the need to remove more bone from the pelvis. There are no long-term studies of resurfacing yet.
And there are serious risks, including fracture of the neck of the thigh bone because it is hard for surgeons to preserve the blood supply to the bone during surgery. Many people do not qualify for resurfacing, if they have kidney problems or weak bones from osteoporosis or are women of childbearing age. The resurfacing devices are "metal on metal," which means metal ions can get into the bloodstream and potentially affect the fetus.
The ideal solution, said Millis, is to have joint-saving surgery, which, if done in time, can often delay or prevent the need for total hip replacement or resurfacing. Most people who have osteoarthritis develop it because of mechanical problems - an alignment problem or an abnormality in the shape of the hip joint.
"Some people with even major hip pain have hips that can be saved," Millis said.
For Jeff Stewart at least, resurfacing has brought a new lease on life.
"Growing up," he said, "I couldn't open my legs more than two feet" because of his hip deformity. "Now, not only can I stretch, I can drive my motorcycle [without pain]. And I do 30 minutes of cardio in the morning, paint all day, go to the gym for another 30 minutes of cardio, and lift weights. It's amazing."
Judy Foreman can be reached at firstname.lastname@example.org.