ROSA®, the Robot That Helps Surgeons Replace Your Knee

Moving from ready-to-wear to tailor-made. That’s the promise ROSA® offers to all those who need a knee prosthesis. ROSA® is nothing more than a robot composed of a computer, a sterile arm, and a camera. Its role is not to replace the surgeon but to assist during the surgical procedure.

In Switzerland, around 20,000 people each year receive a knee implant, mostly due to osteoarthritis—a degenerative joint disease that becomes more common with age. This high number is steadily increasing as the population, though aging, remains more active and less tolerant of joint pain that limits mobility and independence.

The knee is a highly sophisticated joint, made up of bones, ligaments, menisci, and cartilage, capable of very complex movements. Its replacement is delicate, requiring accurate positioning of the prosthesis to best restore joint function.

Significant Advances

Over the past 50 years, knee orthopedic surgery has made enormous progress. It has evolved from nearly artisanal procedures to highly precise interventions, thanks notably to MRI and custom guides that allow precise cuts and optimal prosthesis adaptation to the patient’s anatomy. These improvements have significantly enhanced patients’ quality of life. However, about 20% of patients still report persistent pain long after surgery.

This is where ROSA® comes in. This innovative robot enables even more accurate placement of the prosthesis, adapting not only to the patient’s knee anatomy but also to the degree of joint wear and ligament balance. From the beginning of the operation, and thanks to transmitters, ROSA® collects highly detailed information on the knee's positioning—both statically and dynamically.

While MRI only provides a static image, ROSA® delivers a dynamic and detailed assessment in just 5 to 6 minutes, taking into account the specific bone and ligament constraints of each patient.

Optimal Positioning

These data then guide the surgeon—still under ROSA®'s assistance—to perform cuts and optimally position the three components of the knee prosthesis. This way, the joint’s anatomy is replicated with great precision, and its motion dynamics are respected.

The operation lasts only 15 to 20 minutes longer than a traditional procedure, is less expensive than using custom guides, and according to early studies, results in reduced post-operative pain and a quicker recovery of knee flexion.

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Expert Opinion – Dr. Jacques Blanchard, FMH specialist in orthopedic surgery and traumatology:

What does ROSA® offer compared to traditional knee prosthesis techniques?
ROSA® is a robot that allows implantation tailored to each patient's specifics, with much more precise and anatomical positioning, while ensuring proper ligament tension at the end of the procedure. That’s its major advantage.

What benefit does this have for patients?
Previously, 1 in 5 patients reported significant, lasting pain after knee prosthesis surgery. With ROSA®, which allows for a more personalized fit, we achieve better joint balance. Although long-term data is still limited, my initial patients seem to experience less pain and recover more quickly.

What happens if the robot breaks down?
The surgeon is always the one performing the surgery—not the robot. So in case of malfunction, we switch back to the traditional technique using an intramedullary alignment method.

Will a knee prosthesis installed with ROSA® last longer?
We don’t have enough long-term data yet, but since the knee's balance is better preserved, we can reasonably expect the prosthesis to last even longer than the current 20-year average seen in 95% of patients.