Joint replacement has come a long way since its inception, and in just the past few decades the field has advanced in leaps and bounds. New approaches and tools, matched with faster recovery times, is helping patients get back to life even faster.
Joint pain affects more people than you may imagine.
The CDC says a quarter of adults with arthritis – some 15 million people – experience severe joint pain because of their condition. Half of those individuals have persistent pain.
When persistent joint pain can no longer be assuaged by non-surgical treatments, many patients turn to orthopedic surgeons for relief.
Fortunately, the joint replacement procedures available to patients today are much different from what your grandparents may have experienced.
That’s a comforting thought, because the number of total knee and hip replacements being completed in the U.S. is increasing.
“It’s steadily going up nationwide and predicted to go up quite a bit in the next decade as the baby boomers age,” says Dr. Brian Flanagan, a fellowship-trained orthopedic surgeon at Northwestern Medicine Huntley Hospital. “And people are not OK with just sitting at home in pain and not doing the things they like to do anymore. People want to fix their problem rather than live with it.”
UCI Health (University of California, Irvine) predicts that by 2030, the number of total knee replacements in the U.S. could increase by more than 600% – and hip replacements could increase by nearly 200% – compared with rates in 2005.
The demographics for those receiving joint replacements also are shifting younger. In years past, surgeons didn’t like to operate on patients they deemed “too young” because the probability of second or even third surgeries was higher, merely because the implant components would wear out.
However, implants are now built to last longer, which helps many surgeons feel more confident in allowing younger patients with severely painful knees or hips to receive arthroplasty, the medical term for joint replacement.
“I recently did a hip replacement on a chef who’s getting ready to open a restaurant,” says Dr. Kenneth Chakour, a fellowship-trained orthopedic surgeon who specializes in robotic knee replacement at Fox Valley Orthopedics. “He’s 31. He couldn’t stand long enough to cook. There’s no reason he should go suffer and lose his job just because he’s young. I wouldn’t trade doing surgery later in life for five or 10 years of not being able to do what you love to do.”
“When a 30-year-old does come in who absolutely does need a joint replacement, we would do it now, because it will probably last them most of their life,” he says.
Patients with joint pain often don’t want a sedentary lifestyle, says Dr. Marc Angerame, a fellowship-trained orthopedic surgeon at Barrington’s Illinois Bone and Joint Institute and Advocate Good Shepherd Hospital.
“People are very health care savvy these days; they know what they want,” Angerame says. “And joint replacement is something that’s going to allow people to live their lives, enjoy their grandkids, take walks with their loved ones, play basketball, go skiing, go mountain climbing – and that just increases the satisfaction of somebody’s life. That’s the beauty of joint replacement. Most people understand that when they have an arthritic joint and conservative management no longer works, it’s time for joint replacement.”
The underlying problem of joint pain – arthritis – is the same now as it was decades ago.
“Arthritis is the loss of cartilage over time,” Angerame says. “There isn’t any injection, there isn’t any pill, there isn’t any therapy that is going to put cartilage back on the bones that God gave them at birth.”
Most people live quite a long time with arthritis without having symptoms, he adds. It’s only when a patient begins to experience symptoms that treatment begins.
“And we start small,” Angerame says.
Anti-inflammatories, cortisone injections and physical therapy can help to delay a surgical procedure. But when pain persists despite treatment, more-drastic measures become inevitable.
“When their symptoms have overcome conservative management, that is only when the surgical discussion will be had,” Angerame says.
For knees, that involves removing the damaged surfaces of the knee joint and resurfacing it with new components, which typically include a tibial (shin bone) component; femoral (thigh bone) component; and patellar (kneecap) component.
Similarly, in a hip replacement the damaged bone and cartilage are removed and replaced with artificial components to re-create the ball and socket of the original joint.
There are a lot of misconceptions about joint replacement surgery because it has evolved so much during the past 20 to 30 years, Flanagan says.
“People who had a relative who had it done 15 years ago, their experience might be totally different than it is now,” he says. “You do have to realize things are not necessarily the same as they used to be.”
What makes joint replacement surgery so different these days, as opposed to the past?
While it’s true that the general prosthetic hasn’t changed much over the decades, says Angerame, it’s the subtle advancements in components and techniques that are making a difference.
“The plastic itself has gotten much more resilient,” he adds. “Patients shouldn’t, according to data, have to go back to the operating room in 10 to 15 years for a redo. We’re expecting a much longer longevity.”
“Nowadays, we tell people the implant lasts twice that long,” agrees Flanagan. “That makes a big difference if you’re 60.”
Another advancement is the use of cementless implants. Years ago, many surgeons used cement to bind an implant to a patient’s bone. Over time, the cement would become loose, which led to pain and joint failure. It’s one of the leading causes of revision surgeries, Chakour says.
Today, 95% of Chakour’s knee replacement surgeries are cementless. The component is 3-D printed to match the porosity of the patient’s bone, and Chakour can make sure the patient’s bone will grow into the implant, creating a permanent bond.
“3-D printing has changed the game on that,” Chakour says. “It’s one less mode of failure.”
If there could be a silver lining in the global pandemic, it’s that the majority of joint replacement surgeries are now outpatient procedures, local surgeons say.
“COVID really accelerated that,” says Flanagan. “No one could stay overnight in the hospital even if they wanted to.”
However, the main reason joint replacement surgeries work as outpatient procedures is because of the advancements in post-operative pain management. A rapid recovery pathway has really taken hold over the past three to four years, Angerame says.
“Through new and improved regional anesthetic pain blocks that last longer, numbing medication put around the knee and hip before surgery is allowing patients to get up and walk around the hospital the same day,” he adds.
Improved pain management is also being coupled with minimally invasive techniques that make it possible to avoid cutting tendons or muscles.
“The principle is, the less tissue you have to touch results in less trauma during the surgery and consequently faster recovery times,” Angerame says.
Additionally, increased use of technology like MRIs and CT scans before surgery makes it possible for surgeons to make custom bone models that assist them with aligning the new joint during surgery. It doesn’t mean surgeries are faster, but they are more efficient with less instability and malalignment, Angerame says.
“Really, what is going to be helpful is the advancement of not having to stay in the hospital for two to three days compared to eight, nine years ago,” he says. “You’re up and walking hours after the operation because our pain management is better. How the surgery is done – the efficiency – is better, leading to less pain. Recovery is faster.”
Walking through the Process
To be clear, orthopedic surgeons typically don’t believe surgery should be a patient’s first option.
“Usually, patients will start with their primary care doctor,” Flanagan says. “They almost always get an X-ray. If an X-ray is inconclusive and a physical exam is inconclusive, an MRI can give better visualization, or another scan can give you better information if a joint needs to be replaced. We try to put it off as long as possible. If non-operative treatment works, we tend to push that.”
But if surgery is the only option, here’s what you can expect: The surgery itself tends to be the “easy part,” Flanagan says, and it typically lasts an hour or two. It’s the rehab portion that patients need to prepare for.
“On the day of surgery, patients get enough pain blockers and numbing medications to feel good enough to go home the first day,” he says. “There is the expectation that that stuff wears off and it will start to hurt, but the whole goal is to get up and moving right away. Joints get stiff if they’re not moving, especially if they just had surgery on them.”
Physical therapy typically starts the day of surgery or the day after, Flanagan adds. Most knee surgery patients go about three days a week for six weeks; hip patients don’t usually have therapy, but they are expected to do home exercises.
“The pain waxes and wanes, but typically within the first two to three days things max out,” Flanagan says.
Patients should have an open mind when it comes to post-operative expectations, he adds. They may require the use of a walker for the first few days, then a cane. After two to three weeks, they can walk more freely.
Many patients see their surgeon two to three weeks after surgery, and an X-ray is usually taken to check on their implant, Flanagan says. Doctors also discuss the continued use of blood thinners. Every surgery runs the risk of a blood clot, so patients often take aspirin.
“By six weeks, most patients are happy they did the surgery,” Flanagan says. “They can tell things are getting better and this is a different pain than they had before surgery. Patients who’ve had a previous joint replacement 10 to 15 years ago, typically if they do it now it’s a much better experience. Most patients say it’s night and day.”
Robotics is Now
Though the use of robotic-assisted technology has been around for more than a decade, it’s still considered one of the newer advancements within joint replacement. And it’s gaining traction.
The American Academy of Orthopaedic Surgeons says the percentage of elective primary total knee arthroplasty cases utilizing robotic assistance is now close to 12%. There are several robotic systems available; surgeons, hospitals and clinics simply choose the right fit for their practice.
Flanagan, for example, uses Mako Robotic Arm Assisted technology; Chakour uses the VELYS Robotic-Assisted Solution.
The Mako system takes advantage of CT-based technology.
“You get a CT scan – a 3-D X-ray of your leg – before surgery. That helps with alignment, implant sizes and perioperative planning,” Flanagan says, noting those factors help control the tightness or looseness of the replacement knee. “A good knee, whether done by hand or robot, will still turn out just fine. But the robot is like a backup. It’s double-checking the surgeon to make sure things are done the way you want them to be done.”
Similarly, robotic technology helps with the placement of a new hip socket.
“The angles of the socket are important for the longevity of the implant and for popping or dislocating it,” Flanagan says. “It helps with sizes of the implant and leg length, too. You can double check with an X-ray, but a computer robotic system does that in half the time for you.”
The VELYS system is imageless, so preoperative CT or MRI scans are not needed to perform surgery. Instead, the robot system helps Chakour to execute the surgery. The simplest way to visualize the equipment is a combination of computer, camera and robotic arm that holds a saw during surgery.
When surgeons place pins, or touchpoints, on the bone, the robotic arm assists with the cut by preventing surgeons from deviating, he says.
“I am using the robot to plan the surgery in real time and then execute that plan, but I am in control of the saw during that time,” he says.
With a robot, surgeons can keep their cuts within one millimeter of accuracy, leading to more-reliable outcomes.
“Of course, I don’t need a robot to do surgery,” Chakour says. “But I’d argue that less than a millimeter accuracy time and time again is not attainable without a robot. I compare it to using a GPS. I know how to get home from my clinics, but I also check the best way to get there.”
The robot also allows for restricted kinematic alignment, a technique that helps adapt the implant to a patient’s soft tissue.
Traditionally, surgeons were taught to cut the knee at a 90-degree angle. But for patients born bowlegged or knock-kneed, this straight cut doesn’t compensate for the slight twist of the bone and the way the soft tissue originally fit around the joint. A robot can help surgeons cut less tissue and balance the knee closer to its original position.
“We’re not all born with our legs perfectly straight,” Chakour says. “So, having to do less soft tissue work, it leads to less pain and ideally better outcomes.”
During his fellowship in 2018, Chakour was involved in a study on patient satisfaction following robotic-assisted joint replacement surgery. At the 10-plus year mark, implants had well over 96% survivorship, he says. That’s great news, but there still isn’t hard data to support the theory that robotic systems provide better results.
“A better-balanced knee with accurate placement of components, in theory, should last longer than another knee, but it hasn’t been proven yet,” Chakour says.
However, the collection of data itself is a huge benefit.
“I think embracing things like artificial intelligence to help us look at all the data – because aside from being robotic assisted during the surgery, there’s tons of data being collected – it helps us address the outliers and minimize those,” Chakour says. “More data is always beneficial for us to make educated decisions.”
Chakour believes AI will become more prominent in medicine in time, and that’s likely to spur even more advancements in the field.
“But I don’t think we’ll ever get to where robots are conducting surgery by themselves,” he says. “There’s a little bit of art and decision-making that is crucial for the personalization of each surgery that will always require a surgeon.”