Meeting the demand with 30-year knee implants and new surgical techniques
“The majority of people coming into my office for knee replacement surgery are in their 50s,” says Steven Haas MD, Chief of Knee Surgery and Attending Orthopedic Surgeon at the Hospital for Special Surgery in New York City. This is a big shift in demand compared to 20 years ago, when fewer than 10% of knee replacement patients were in their 50s.
Innovative technologies in implant design and surgical techniques are meeting the growing demand for knee replacements among active Baby Boomers, providing both longer-lasting results and a faster recovery.
The FDA recently cleared a 30-year knee implant, based on simulated wear tests that showed an 81% reduction in wear, the leading cause of knee replacement failure. The implant uses VERILAST technology – a combination of oxidized zirconium (OXINIUM) for the femoral component and cross-linked polyethylene (XLPE) on the tibial side. As older knee implants made from chrome cobalt metal usually lasted only about 10-15 years, surgeons were reluctant to put them into people under 60 years old – they tried to match the implant survivor curve to the predicted lifespan of the patient.
Dr. Haas says that more recent knee implants are more functional than earlier versions, because the design has come a long way to fit the anatomy of the patient as closely as possible and provide a more natural articulation compared to the first knee implants that only hinged and were the same for both left and right sides.
Surgeons are also now using smaller instruments and minimally invasive surgical techniques to minimize trauma to the patient, leading to faster recovery. Dr. Hass developed the first minimally invasive surgical instruments in 2003. He says, “What we want to do is cut as little as possible to put the parts in, to do as little collateral damage to get access and minimize the trauma. With more anatomically shaped instruments, we are making the instruments fit the opening instead of the opening fit the instrument.”
Minimally invasive surgical techniques involve using smaller incisions to access the knee area after the patient receives a local anesthetic via epidural. The knee replacement operation is performed without needing to cut the quadriceps tendon or flip the kneecap upside down to gain access, as was required with older surgical techniques. Recoveries for patients who receive the minimally invasive surgical technique are significantly faster: most patients are able to resume their activities 6 weeks after surgery rather than 3 months.
Longer lasting implants and a quick recovery are appealing considerations for Baby Boomers, especially since the need for knee replacement is on the rise for that age group. Those in their 50s in general are more active than people in that group were a generation ago and they expect to maintain that active lifestyle for as long as possible. Expectations for the variety of activities have changed as well. Dr. Hass reports that Baby Boomers won’t settle for just walking around the block, “they want to be able to bike, hike, play tennis, ski, dance and play with their kids.”
All of this was good news for Jane Byron, age 51, a nurse who had both knees replaced in 2010 by Haas. An extremely active person who works on her feet and works out at the gym everyday, Jane tore her meniscus in a rollerblading accident. Subsequent arthroscopic surgery did not address her mobility issues. After minimally invasive surgery with new knee implants, she was pedaling a stationary bike for 45 minutes two days after surgery and pressing 75 pounds on the squat rack two months later.
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Learn more about the Hospital for Special Surgery in New York City, where more knee replacements and hip surgeries are performed than any other hospital in the U.S. Read stories about other patients who have had minimally invasive surgery for knee implants. Visit Smith & Nephew to learn about total knee replacement and VERILAST knee implant technology. You may also like this story: The Benefits of Arthroscopy for Hip Surgery.