HN Summary
• A large Ontario-based study found robotic-assisted total knee replacement is linked to double the rate of major complications within one year (2.0% vs. 1.0%) compared to conventional surgery.
• While robotic systems aim to improve implant alignment, they can add surgical complexity, longer operating times, and additional procedures, without demonstrating consistent clinical benefit in routine practice.
• Findings suggest cautious adoption of new surgical technologies, reinforcing the need for evidence-based decision-making and continued focus on proven improvements in patient care.
A new study shows that robotic-assisted total knee replacement (arthroplasty) surgery is associated with double the risk of major surgical complications within one year, compared to the conventional version of the surgery.
“Robotic technology used for total knee arthroplasty (TKA) is different from robotic systems used in other types of surgery, as it is designed primarily to improve implant alignment, not to make the operation minimally invasive,” says Dr. Daniel Pincus, primary author of the study, an associate scientist in the Holland Bone and Joint Research Program at Sunnybrook Research Institute. “Outside of specialized high-volume arthroplasty centres, evidence of consistent clinical benefit and safety in routine practice has been limited.”
To help address some of these uncertainties, the investigators aimed to determine whether robotic-assisted TKA was associated with lower complication rates compared with conventional TKA, but the results show the opposite.
Newly published in The Journal of Arthroplasty, the large population-based study looked at all adult surgical cases in Ontario who received their first primary elective TKA for osteoarthritis from April 2019 to October 2023, and were followed for one year after surgery. Almost 75,000 total knee replacement surgeries were performed across 62 hospitals by 345 surgeons: 1,613 of which were robotic-assisted TKAs and 72,746 were the conventional surgical method.
The primary outcome of the research was to look for major surgical complications such as the need for revision arthroplasty, deep infection requiring surgery, or fracture requiring surgery, within one year of surgery.
Compared to matched conventional TKA patients (with a 1.0 per cent rate of major complications), those undergoing the robotic-assisted surgical approach had a significantly higher rate (at 2.0 per cent of major complications).
“In practice, the robotic technology used in TKA requires additional pin sites in bone, larger or extra incisions, longer anesthesia time (101 minutes versus 89 minutes for conventional TKA), and higher cost,” explains Dr. Pincus, also an assistant professor in the Division of Orthopaedic Surgery at University of Toronto’s Temerty Faculty of Medicine.
Among experienced knee surgeons, these findings are not particularly surprising, suggests senior author of the study, Dr. Bheeshma Ravi, an associate scientist at ICES and the Holland Bone and Joint Research Program at Sunnybrook: “Conventional knee replacement is already performed to a very high standard across Canada, so new technologies may have difficulty outperforming what surgeons are currently achieving. In this study, the robot did not — it added time and complexity, and we observed higher complication rates.”
The authors stress that decisions on adopting new technologies must remain evidence-based and each innovation evaluated on its own merits. Attention should not be diverted from other advances, such as improvements in implant design and perioperative care pathways, which may have a greater impact on patient outcomes, they say.
“The benefits of current generation robots in total knee arthroplasty appear more limited than many may expect,” adds Dr. Ravi, also an associate professor in the Department of Surgery at University of Toronto’s Temerty Faculty of Medicine. “In healthcare, we’ve learned that introducing technology doesn’t automatically improve outcomes. Innovation is important, but history shows early versions of complex technology often need refinement before they actually help patients. Robotic technology will continue to evolve, but our findings suggest limited implementation is appropriate until the devices improve and clinical benefit for patients is demonstrated.”
Robotic adoption of arthroplasty surgical cases increased from 1.7 per cent of cases in 2019 to 5.8 per cent in 2023, and is continuing to expand.
Although reviews have called for large randomized clinical trials directly comparing robotic-assisted TKA with conventional TKA to establish whether one approach is preferable, such studies face practical challenges such as placebo effects and the inability to blind patients and surgeons to robotic technology.
This study – supported by the Arthritis Society, the Marvin Tile Chair in Orthopaedic Surgery at Sunnybrook Health Sciences Centre, and by ICES – an independent research institute funded by the Ontario Ministries of Health and Long-Term Care – adds to the existing evidence base by including a large, diverse, population-level cohort and by reflecting contemporary practice between 2019 and 2023.