A novel AI developed at Alexandra Hospital automates implant positioning in robotic total knee replacement surgery. 

A team at Alexandra Hospital's Department of Orthopaedic Surgery recently obtained the World Intellectual Property Organization patent for their AI algorithm.

WHAT IT DOES

Developed by Dr Glen Liau Zi Qiang, an orthopaedic surgery consultant at AH, the AI optimises implant positioning in preparing for robotic TKR by accounting for the patient's unique bony and ligamentous anatomy and the surgeon's objectives. It considers at least eight degrees of freedom and their interdependencies in computing for optimal implant placement.  

More than 150 patients at AH have successfully undergone the AI-assisted robotic TKR since it was introduced in 2023.

WHY IT MATTERS

TKR is a common orthopaedic procedure for patients with severe knee pain, especially due to osteoarthritis and similar degenerative conditions. 

Robot-assisted TKR has increasingly become a preferred option due to its high precision and potential for improved outcomes. 

However, the technology does not always guarantee the best implant positioning. This complex process requires three-dimensional space consideration of the two implants in at least 8 axes of degrees of freedom. Surgeons performing robotic TKR still plan this manually; they also adjust the positioning of the femur and tibia implants intraoperatively. 

AH's AI for robotic TKR has been shown to greatly raise the accuracy of planning for the procedure, saving surgery time which can also translate into reduced blood loss and shorter anaesthesia duration. 

In a two-year prospective study involving 67 patients, over nine in 10 procedures powered by the AI achieved surgeons' defined target gaps (within ±1.5mm). These AI-assisted procedures also achieved optimal gap balancing in under 0.1 seconds, compared to 15 minutes in manually-planned surgeries. Additionally, robotic TKR procedures using the AI were completed 48% faster than those manually planned. 

According to AH, high accuracy in planning for implant positioning can potentially lower the risk of postoperative complications, such as loosening, wear, and instability, reduce the number of revision surgeries needed, and contribute to better long-term implant function and longevity.  

MARKET SNAPSHOT

Outside Singapore, robotic TKR is also offered in South Korea. Last year, the Catholic University of Korea St Vincent's Hospital introduced the procedure, powered by Stryker's robot-assisted system. 

AI-augmented robotic surgeries are also increasingly adopted across Asia-Pacific. South Korean hospitals, Samsung Medical Center, Kyungpook National University Hospital and Yangsan Pusan National University Hospital, offer the AI-driven RAS for kidney stone surgery, Zamenix by Roen Surgical. BLK-Max Super Speciality Hospital, a private tertiary healthcare provider in India, also has an AI-powered robotic system for joint replacement surgeries.