Cutting-Edge Knee Surgery Comes With a Catch

Sunnybrook research finds robotic-assisted knee replacement doubles complication rates compared to conventional surgery in routine hospital settings

10 Apr 2026

A major study from Sunnybrook Research Institute found that patients who underwent robotic-assisted knee replacement faced double the complication risk within one year compared to those who had conventional procedures. The findings, published in The Journal of Arthroplasty, draw on nearly 75,000 surgeries across 62 hospitals between 2019 and 2023.

The numbers are stark. Complication rates hit 2.0% for robotic cases versus 1.0% for conventional surgery. Those complications were not minor: they included revision surgery, deep infection requiring an operation, and fracture requiring surgery.

Robotic procedures also demanded more from patients and surgeons alike. Additional pin placements in bone, larger incisions, and an average of 12 extra minutes under anesthesia added cost and clinical complexity, with no measurable benefit in routine hospital settings.

"Conventional knee replacement is already performed to a very high standard," said Dr. Bheeshma Ravi, senior author and scientist at Sunnybrook. "The robot added time and complexity, and we observed higher complication rates."

The study lands at a moment of rapid expansion. In Ontario, robotic procedures climbed from 1.7% of knee replacements in 2019 to 5.8% by 2023. In the US, robotic-assisted joint replacement volumes surged more than 600% between 2015 and 2020, fueled by aggressive manufacturer momentum and the seductive logic that newer must mean better.

The researchers are not calling for a halt. They acknowledge that high-volume specialized centers have shown different outcomes, and that next-generation systems may yet deliver on the promise. But their core message is one of discipline: adoption in routine settings should follow evidence, not sales cycles. In the near term, investments in perioperative care and implant design may do more for patients than the latest surgical robot.

For health systems weighing these decisions, the signal is hard to ignore. Clinical benefit has to lead. Market momentum is not a substitute for proof.