Knee pain in the United States has doubled since the 1940s. Scientists suspect it’s because Americans are living longer, but less active, lives. Plus, one in about 11 adults has severe obesity, which can be a significant contributing factor.

Dr. Timothy Ewald, an orthopedic surgeon at Novant Health Orthopedics & Sports Medicine - Denver, said that carrying extra weight puts added pressure on your joints, and can increase your risk of developing osteoarthritis. That’s the “wear and tear” arthritis that affects more than 32.5 million Americans and serves as one reason why more than 600,000 patients have a knee replacement every year.
And there’s at least one more reason: Baby Boomers are far more active and athletic in retirement than previous generations. The answer to staying on the tennis court and hiking trails has often come with joint replacement.
That said, knee surgery is not inevitable. Ewald said maintaining a healthy weight and exercise regimen can be a powerful strategy to reduce your risk of arthritis and knee pain in the future.
But, for those patients that do require surgery, it’s important to understand how far the procedure has come — thanks to new surgical techniques and technology — since the first knee replacement was completed in 1968. Ewald said that he’s using a newer robotic-assisted surgical system that’s making a big difference for his patients.
What is robotic-assisted knee surgery?
While some patients may have a flashback to Lee Majors playing Steve Austin in the “Six Million Dollar Man” television series, Ewald said robotic-assisted knee surgery is now an everyday option for many patients.
“Today, most of my partial and total knee replacement patients are able to benefit from robotic-assisted knee surgery,” he said. “But I’m always quick to clarify exactly what that means.”
In short: Robots don’t perform the operation. Surgeons still do that. But Ewald has the added benefit of utilizing the CORI Surgical System, a surgeon-controlled handheld robotic technology.
Find an orthopedic doctor near you.
How does it work?
Before starting the procedure, the surgical system uses an advanced infrared tracking system to create a 3D digital model of the patient’s knee. Overall, the robotic-assisted knee replacement procedure is less invasive than that of conventional surgery.
Check out the video of the CORI Surgical System at the end of this article.
More than one option

Dr. Charles Craven, an orthopedic surgeon at Novant Health Orthopedics & Sports Medicine – Clemmons, is also a big proponent of robotic-assisted knee surgery.
Craven utilizes the state-of-the-art Mako surgical system, which is available across Novant Health medical centers.

The Mako surgical system takes a different approach when creating the preoperative plan. It uses a patient’s CT scan to generate an interactive 3D virtual model of the knee. That allows Craven to assess the bone joint from all angles and determine the precise size and orientation of the implant. It also allows him to map out the entire procedure before making the first incision. He then guides the robotic arm, which provides real-time feedback to ensure accuracy, as he removes damaged bone and cartilage and places the implant.
“When people ask me why I do robotic-assisted surgery, I tell them that it all comes down to improving the lives of my patients,” Craven said. “Historically, some studies have shown that up to 20% of patients are dissatisfied after their traditional knee replacement procedure. That percentage is way too high, and robotics is helping us move the needle in that area.”
While both surgical systems possess unique characteristics, they each function similarly and serve the same purpose: to aid the surgeon in the best possible outcomes for patients.
Know this: Most insurance companies now cover the cost of robotic-assisted partial and total knee replacement procedures.
A faster recovery
Today, most knee replacement patients are able to get up and walk within hours of their surgery. And what used to be a week or two stay at the hospital has now been reduced in most cases to a single night. Some patients even go home the same day.
Outside of robotics, Ewald and Craven both attribute the dramatic reduction in recovery time to Novant Health’s embrace of the Enhanced Recovery After Surgery (ERAS) treatment program. The goals of the ERAS program include: shorten recovery time and hospital stays, decrease the patient’s risk of complications and improve patient satisfaction after surgery.
“Twenty years ago, it was not uncommon for prolonged hospitalizations after joint replacement, sometimes upwards of a week,” said Craven. “But research has revealed that it’s better to get patients up and moving as soon as possible.”
Those conversations begin before surgery even takes place. Patients are educated on the front end about the importance of nutrition and physical activity before and after surgery. The ERAS program also helps to reduce the risk of post-surgical complications, like blood clots and infections.
“Knee replacement surgery has come a long way over the years,” said Ewald. “Outside of using new technology in the operating room, we spend a great deal of time helping our patients to prepare to have a good outcome and a quick recovery.”