SANTA ANA, Calif. — Denise Olson danced at her daughter’s wedding.
That might not sound like a profound accomplishment, but it was a moment she could only dream of a few months earlier. Arthritis had worn away so much of the cartilage in Olson’s right knee that it was just bone grinding on bone. The pain had steadily worsened for two years, making it difficult for her to walk up the stairs of her home. She teaches first grade in Irvine, and it’s tough to meet the all-day needs of 30 kids when you can barely rise from your chair.
On April 23, she had total knee replacement surgery. Four weeks later, she was back in class. On July 13, her daughter Lauren got married, and Denise was able to walk down the aisle.
Later, during the reception, when Denise and her husband, Chad, were sitting together, the DJ played “Come Away With Me” by Norah Jones, which happens to be the couple’s song. He invited her onto the dance floor. She accepted.
“Just the two of us got up and danced on the floor. It was wonderful,” said Olson, who is 54. “I got to dance with my daughter and my son-in-law. And the party went on until the closing hours.”
Better implants, improved surgical techniques and a more in-depth understanding of how to treat a patient’s pain during and after surgery have helped make total knee replacements available to a wider patient base, from younger people like Olson to long-suffering seniors.
The evolution of the procedure comes at a time of surging demand: About 600,000 total knee replacements were performed in the United States last year, and that number is expected to increase to 3.5 million a year by 2030.
"The need for surgery is exploding," said Dr. James T. Caillouette, surgeon in chief at Hoag Orthopedic Institute in Irvine, Calif.
Shorter hospital stays and faster, less painful recovery periods have made the operation popular among patients who are both older and younger than used to be the norm for such candidates. Baby boomers are hitting the age at which their knees are wearing out, and they're not willing to give up their active lifestyles without a fight.
"I would say at least half of my patient population is under 65," Dr. Caillouette said. "Twenty years ago, that was not the case. But it's not unusual for me to see a patient in their late 30s or 40s with end-stage arthritis who needs surgery. We used to be very fearful of doing that, because we didn't think the implants would last very long. Now, with the new generation of designs and materials, they look like they're going to last a very long time, 20 to 30 years or longer."
But even the boomers' Greatest Generation parents are getting the implants in higher numbers. Life expectancy keeps increasing, of course, but there's also a greater awareness of how quickly health can decline if immobility leaves an elderly person homebound and isolated.
Total knee replacement, also called arthroplasty, might be a misnomer: The entire knee isn't cut out. In fact, many of the parts are kept in, including the ligaments at the edges of the joint, the lateral and medial collateral ligaments, as well as the patella bone and its own ligament.
The procedure is commonly recommended in people whose articular cartilage, which covers the thigh bone (femur), has been ravaged by degenerative osteoarthritis. The meniscuses, the disc-shaped pads between the cartilage on the femur and the shinbone (tibia), can also wear over the years.
The femur and tibia are shaved down to make way for the implant, which resurfaces the bones. "Imagine you're essentially doing a retread on a tire," Dr. Caillouette said. Most implants have a metal "tray" that holds a plastic platform that stands in for the meniscus. The covering on the femur is super-strong metal, and when the knee bends, the pieces glide on top of one another.
Earlier generations of the implant used titanium, but that metal was found to wear out too quickly, Dr. Caillouette said. Newer models use cobalt-chrome, a longer-lasting alloy. The plastics in them also are harder and more wear-resistant, said Dr. Caillouette's colleague, Dr. Robert S. Gorab, the chief medical officer at Hoag Orthopedic Institute.
Hoag Orthopedic Institute, which opened in November, 2010, has become one of the highest-volume orthopedic centers in the country. Nearly 1,500 knee replacements were performed there in 2012, a 28 percent increase over 2011. DePuy, a Johnson & Johnson Co., launched the Attune in March (Dr. Caillouette implanted the first one on the West Coast), and between that model and the others, the 70-bed hospital should become an even busier place.
Patients are usually kept for at least one night after undergoing the procedure, but the protocol for their treatment has changed vastly over the years.
Knee surgery hurts, a lot, and this used to be a deal-breaker for many patients. But Dr. Caillouette says patients receive different kinds of pain treatment: Gone are the days when only general anesthesia would be used, leaving the patient groggy and out of sorts upon awakening. Also, more care is taken to avoid cutting some soft tissue inside the knee.
"Now a patient will wake up from surgery without pain," said Dr. Caillouette, who along with Dr. Gorab is a founding partner of the Hoag institute. "They don't need IV narcotic pain medicine around the clock, because we're giving them little doses of different things, as opposed to hitting them with a sledgehammer."