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Robotics at the Tipping Point
Adult Orthopaedics

Robotics at the Tipping Point

HSS surgeons share where they are and where they’re headed in shaping the future of robotic-assisted orthopaedic surgery.

THE ELDERLY PATIENT HAD TO COME TO HSS for a total knee replacement (TKR) after multiple prior knee procedures. His surgeon, HSS Sports Medicine Service Chief Andrew Pearle, MD, noted the extensive soft tissue damage around the patient’s joint. Using robotic technology with advanced imaging capabilities, Dr. Pearle factored this into his planning, modeling a larger-than-average femoral component to ensure greater stability.

Without the robotic platform, Dr. Pearle says he would have had to make standard cuts instead of personalizing the procedure for the patient’s specific pathology.

“In this case, we used the robot to make our cut on the tibia and then we used a device to tension the ligaments,” he explains. “We could upsize the femur and cut less bone than we normally would have. This saved the patient from the need for a more constrained device, which ultimately will allow, I believe, for a longer lasting prosthesis.”

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Preoperative planning for a robotic partial knee replacement, which factored in prior damage to the knee joint. Image courtesy Andrew Pearle, MD

For many cases of total knee arthroplasty, it’s not necessary to use robotics for optimal results, according to Dr. Pearle and many other joint replacement surgeons at HSS. But for the inherent technical challenges of partial knee replacements, Dr. Pearle says, robotic technology has transformed his practice.

He performed the first robot-assisted partial knee arthroplasty at HSS almost 15 years ago; since then, robotic assistance has become the standard for him and many of the surgeons at HSS.

“Traditionally, manual insertion was tricky because you had to match the patient’s anatomy just so,” says Steven B. Haas, MD, Chief of the Knee Service at HSS and an expert in minimally invasive procedures. “Robotics addresses exactly what is important: The placement of the implant is very precise, and it matches that person’s anatomy exactly.”

And results have been encouraging: a multicenter study published in the Journal of Arthroplasty in 2018 reported a 3% revision rate at five-year follow-up for partial knee replacements performed with robotic assistance in comparison with a 6% revision rate in conventional unicompartmental knee procedures, according to a systematic review published in 2015 in The Knee.

Building on that success, a growing cadre of HSS surgeons are pioneering the use of robotic systems for an expanding list of surgeries of the knee, hip and spine, often using minimally invasive techniques.

3%revision rate post-surgery with robotic assistance
6%revision rate in conventional surgeries


“Across the board, a lot of the innovators in robotic surgery are right here at HSS,” says Sheeraz Qureshi, MD, MBA, an expert in minimally invasive spine surgery and an associate attending orthopaedic surgeon at HSS.

We’ve helped to innovate beyond just putting in screws, but actually in how to prepare disks and put in interbody implants to restore height and alignment

About three years ago, HSS became one of the first spine programs in the country to start using the latest iteration of robotic technology. “We’ve helped to innovate beyond just putting in screws, but actually in how to prepare disks and put in interbody implants to restore height and alignment in the spine,” Dr. Qureshi says. “These are all additive technologies that allow robotics to be part of the entire procedure.”

Dr. Qureshi now performs almost all of his surgeries with robotic assistance. While it’s too early for him to say definitively that robotic-assisted surgery results in better outcomes, initial indications are positive.

“We have found certainly that the accuracy is great, there’s improved consistency in terms of the outcomes, and the patients have less pain after surgery when we perform an operation in a less invasive manner,” Dr. Qureshi says.

Robotic surgery is gaining wider acceptance in spinal surgery thanks to its integration with advanced navigation technology, says Darren Lebl, MD, MBA, an expert in minimally invasive spine surgery and associate attending orthopaedic surgeon at HSS. “With surgical navigation, we can take the patient’s imaging studies to effectively create a 3D map of their anatomy, and then use that in combination with robotics to do our surgeries very precisely and less invasively.”

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A preoperative planning template for a spinal fusion patient showing pedicle screw trajectory with spinal instability due to isthmic spondylolisthesis at L4 Right. Image courtesy Darren Lebl, MD, MBA

Dr. Lebl particularly appreciates the value of robotics in complex cases in which the surgeon encounters an unfamiliar anatomy or is unable to achieve direct visualization—for example, in cases of scoliosis as well as abnormalities such as those associated with Marfan syndrome and other genetic conditions.

“What the navigation combined with the robotics allows us to do is to effectively see the patient’s anatomy without that direct open surgical exposure,” Dr. Lebl says.

The [robotics] application with the greatest potential may lie in cervical spine surgeries

To date, most robotic-assisted procedures have been for thoracic, lumbar and sacral spine procedures. But according to Dr. Lebl and HSS spine surgeon Frank P. Cammisa, MD, writing in a recent issue of the HSS Journal, the application with the greatest potential may lie in cervical spine surgeries. “Precise instrumentation is critical due to the proximity of the cervical spine to the vertebral artery, nerve root, and spinal cord,” they write, noting that the “reproducible anatomical precision” of robotics-assisted platforms could prevent loss of stability or catastrophic neurologic or vascular complications associated with screw malposition.

Sheeraz Qureshi, MD, performs a robotically assisted spinal fusion.

Robotics for Complex Hip and Knee Arthroplasty

While the use of robotics platforms has become increasingly commonplace in spine surgery, robotics is also at a tipping point in total hip and knee replacement. A 2021 study led by HSS hip and knee surgeon Geoffrey Westrich, MD, and published in Arthroplasty Today reported a nationwide jump in robotic-assisted procedures of more than 2,200 percent between 2010 and 2018.

2K%jump in robotic-assisted procedures (2010 to 2018)

Additionally, the study, which assessed 1.3 million TKRs using a national database and categorized them as conventional, technology-assisted or robot-assisted, showed lower complication rates in the first three months after surgery.

At HSS, joint replacement surgeons are exploring the use of robotics for the complex procedures commonly performed here. David J. Mayman, MD, Chief of the Surgical Arthritis Service at HSS, has been incorporating robotic platforms into his practice for the past 10 years. In particular, he finds that robotic-assisted surgery can overcome the challenges of significant hip dysplasia.

“Sometimes, it can be very difficult with our manual tools to figure out where to implant the acetabular component,” Dr. Mayman says. “Using the robotic tools along with preoperative planning, that case becomes just as simple as any other hip replacement. That’s a case where there’s a real benefit; even naysayers would say it is a good case for using the robot.”

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HSS joint replacement surgeons can adjust the implant size and position virtually using preoperative planning software to provide optimal fit and ligament balance before any bone is removed. Image courtesy Steven Haas, MD

Robotic technology has also shown promise in complex total knee replacements involving an old fracture or deformity of the joint, says Dr. Haas. “The robot can identify the center of the hip and the whole alignment of the leg that would allow us to make corrections with large, complex deformities.”

Dr. Haas predicts an increasing role for robotics in complex knee replacements, allowing for greater customization in the alignment of the knee and the balance of soft tissue around it. “As time goes on and we learn more about precise targets, it will be a tool that allows us to improve the operation through increasing personalization,” he says.


Surgeons across practice areas acknowledge the learning curve associated with robotics-assisted surgery. The biggest disadvantage they cite is the extra time it initially adds onto procedures as surgeons get used to working with the platforms.

For instance, Dr. Lebl recounts that early on, there were times when his surgical team had to convert to older techniques. But now, with close to 1,000 implants under his belt using robotic technology, he says there’s no need to do so. “Since 2019, I have been doing robotic procedures for every lumbar and thoracic spine operation.”

A a 2021 study led by Dr. Lebl and published in the Journal of Spine Surgery looked at the learning curve for surgeons doing their first robotic surgeries.

“We found that early on it added some time to the procedure in the first 10 cases or so, but later on, once the surgical team was familiar with it, it actually saved time in the operating room,” he says. For implants, they found that placement with the aid of robots was “as good, if not better, than freehand placement.”

For implants, the study found that placement with the aid of robots was “as good, if not better, than freehand placement”
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Dr. Mayman notes that even with a surgeon’s first robotic case, initial data shows they are not compromising quality of care, even though it may take a little longer to do the procedure.

“In some procedures, now I’m faster with the robot than without it because it has led to such a high level of confidence in what I’m doing,” Dr. Mayman adds. “Rarely do you have to backtrack and redo anything.”

That precision and confidence could also have ancillary benefits by helping to improve efficiency in the OR and reduce surgeons’ stress levels. “If I’m doing my third surgery of the day, I have some mental and physical fatigue. I know the robot can hold the trajectory exactly as it needs to be,” says Dr. Qureshi, who is currently studying the impact of robotics on physician stress levels.

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The robot can hold the trajectory exactly as it needs to be

Anecdotally, he says his own stress level during these surgeries “is significantly lower because I know that I’m putting in these perfect screws and getting the visual confirmation. It’s physically and mentally less taxing.”


In a recent editorial in the HSS Journal, Drs. Lebl and Qureshi predicted robotics would play a major role for future generations of surgeons. “Is it realistic to think that future surgeons won’t find a significant place for advanced technology and robotics in their operating rooms? The more difficult stretch of the imagination is that they would not,” they wrote.

It’s true that some surgeons worry that the rise of robotic and other advanced technologies may make surgeons too dependent on technology, ultimately diminishing the art of surgery itself. However, Dr. Mayman draws a parallel with airplane pilots, who used to have to fly their planes manually but now mostly rely on computer navigation: “I want to be on the airplane that has the computer.”

Robotics & Navigation in Orthopaedic Surgery
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