Surgical robot opens the way for greater precision in total knee replacement
The JGH is now among a handful of hospitals in Quebec where a robotic arm is providing crucial guidance when the bone of a damaged knee must be cut precisely during total knee replacement.
“This is the first time in my life as a surgeon that I’ve used an instrument that actually helps me perform surgery in such a dramatic and positive way,” says Dr. David Zukor, Chief of the Division of Orthopedic Surgery.
“Using the robot allows me to truly personalize this kind of surgery to meet the patient’s exact needs. It’s more accurate and more efficient, and I feel it leads to better outcomes.”
In most types of robotic surgery over the past 15 to 20 years, four or five mechanical arms—each with a small medical instrument or fibre-optic camera at its tip—are inserted into the patient’s torso through small incisions.
Instead, Dr. Zukor begins the operation by exposing the knee joint, including the bone, and touching various parts of it with a digital pointer that is attached to the robot. He also manipulates the knee to help the computer recognize how this particular patient’s joint bends, as well as how the ligaments move and are balanced.
A virtual model of the knee
Putting all of this data together, the robot’s computer gains a thorough understanding of the patient’s anatomy and builds a virtual model of the knee.
Next, Dr. Zukor reviews the data on the robot’s computer screen and provides input about how he wants to cut the bone—“and that’s when the beauty starts!”
Based on this information, the robotic arm moves into position next to the knee and indicates exactly where to position the saw blade, so that the cut is made to the proper depth and at the correct angle.
“I look at the screen where the patient’s medical values are outlined in green,” he says. “I take the saw, I do the cut, it’s still green. I take another instrument and validate that I’ve made exactly the right cut, and—boom!—I move on to the next one.
“Those cuts sometimes used to take me 15 or 20 minutes and I couldn’t be sure they were all perfectly accurate. Now it takes literally seconds and they’re always 100 per cent accurate.”
Since the leg is not held firmly in place on the operating table, it might move slightly before the cut is made. If this happens, the robot detects the movement by relying on sensors in the patient’s leg. Then, instantly and automatically, the arm readjusts to the leg’s new position until it is correctly lined up once again.
Knee ligaments are unaffected
Another significant benefit, Dr. Zukor says, is that in most cases, it’s no longer necessary for him to tamper with the ligaments of the knee. As a result, patients who are slightly bow-legged or knock-kneed won’t emerge from the operation with perfectly straight legs that feel unnatural.
And unlike certain robotic systems where a CAT scan must first be performed to help plan the surgery, the technology that Dr. Zukor uses is imageless, working instead with data it receives from the surgical team.
“Not only is a CAT scan expensive and time-consuming, it exposes the patient to a lot of radiation,” he says. “It’s one thing if the patient really needs a CAT scan, but is this what we really want to do just to plan an operation?”
Dr. Zukor notes that some surgeons, including three of his JGH colleagues, still prefer traditional—and perfectly acceptable—techniques for total knee replacement.
Nevertheless, he says, his experiences have convinced him he can now cut bone with unprecedented precision. He believes this has helped patients heal better and faster, eventually enabling them to walk more naturally and comfortably.
To document his experiences, Dr. Zukor is gathering data about robot-assisted operations, of which he performed about 50 between summer 2022 and summer 2023.
However, he is already calling this kind of surgery an authentic game-changer—“and the results are right there in the smiles on my patients’ faces.”