Younger patients find more-durable options for artificial hips and knees

Dan Johnson's balky right hip really started hurting last fall, so much that he never hesitated in getting it replaced. The main question for the 49-year-old, like so many other Americans middle-aged and younger having similar surgery, was ensuring that the artificial hip could stand up to his active lifestyle.

Johnson is an avid golfer and was a runner, hockey player and coach. He wanted a hip that would last longer than the normal 15- to 20-year life span.

He heard about a new product through his doctor: the Verilast system from Smith & Nephew, a British med-tech company. A recent study found it has the potential to hold up for 30 years or more, so Johnson had his hip replaced March 5. "They told me this was not only good for younger patients, but for bigger patients, too," said the Chanhassen 6-footer who was 250 pounds at the time of his surgery. "It's just a lot more effective for me."

Verilast uses a metal alloy called Oxinium, an oxidized zirconium, that transforms the metal on the surface of the hip ball into a ceramic, making for less friction, scratching and abrasion.

At a time when patients receiving replacement hips and knees are getting younger, that growing market is putting more pressure on device makers to develop materials that can withstand the pounding of more active lifestyles. Worldwide demand for artificial hips and knees grew nearly 5 percent this past quarter, analyst Larry Biegelsen of Wells Fargo & Co. said in a recent note to investors, with no signs of abating. Growth in the U.S. for artificial hips was more than 5 percent last quarter, he said.

Smith & Nephew's Verilast technology is seeking to satisfy that demand. Johnson's surgeon, Dr. Jay Johnson of Twin Cities Orthopedics, said he used to counsel his younger patients to hold off on hip replacement as long as they could endure the pain. No longer.

"Should they wait, or should we make hay while the sun shines and they can enjoy their more active years?" Jay Johnson said. "The technology is changing. There are opportunities to have a good life. It's a risk-benefit ratio."

In 2012, a report by the Australian Orthopedic Association National Registry showed that the Verilast ceramicized metal lasts longer and needs revision less often than other bearing surfaces. After seven years, Verilast had the highest "survivorship," according to the report, at 97.8 percent, as well as the lowest rate of revision at 0.46.

"Everything is the bearing surface," said Jay Johnson, who has consulted for Smith & Nephew, but owns no stock in the company. "And the body reacts to wear particles; they eat bone around the implant until it loosens. You want the wear particles to be as minimal as possible. That is what you get with Oxinium."

Smith & Nephew had worldwide revenue last year of $4.1 billion. The company has more than 10,000 employees, including more than 4,000 in the United States. In the most recent quarter, the company's U.S. revenue was up 5 percent; knee replacement revenue was up 2 percent and hip replacement revenue was up 3 percent. Jay Johnson sees such growth continuing — for companies that successfully develop more-durable materials.

"I got guys who play basketball. I got guys who play hockey. I have people in dancing and martial arts," he said of his hip and knee patients. "Even if you are 65 years old, how long are you going to live nowadays? If you are 70 years old, what are the chances of you living to 90? Pretty darn good. Unless you are in your 80s, I use this on almost everybody."

Dan Johnson, who is back to working out and preparing to have his left hip replaced in the not-too-distant future, said the days of waiting for relief are over.

James Walsh • 612-673-7428