Singapore – A new surgical tool is dramatically reducing the risk of fractures during robot-assisted knee replacements, a procedure gaining popularity worldwide. Laboratory tests show the tool cuts fracture rates from 80% with traditional methods to just 30%.
Minimally Invasive Knee Replacement: A Safer Approach
A new jig developed in Singapore aims to make robotic knee surgery even safer and more precise.
- Robot-assisted knee replacement is becoming more common, now accounting for 13% of all such procedures.
- Traditional methods of guiding the surgical robot can weaken bone, increasing fracture risk.
- A new “jig” tool reduces fracture risk by streamlining the pin placement process.
- The tool has been successfully used on over 200 patients in Singapore since 2023.
Robot-assisted total knee arthroplasty offers greater precision and improved outcomes, but it isn’t without risks. A key concern is the potential for fractures, stemming from the need to drill up to four tracker pins into the thigh and shin bones. These pins are crucial for the robot to map the bones in real-time and guide the surgeon, but their placement can compromise bone strength.
Q: What are the risks associated with robot-assisted knee replacement?
A: While offering benefits like precision, the procedure carries risks including fractures due to pin placement, as well as potential wound infections and nerve injuries.
To address this, a team led by Adjunct Assistant Professor Glen Liau, a consultant at Alexandra Hospital’s orthopaedic surgery department, developed a less invasive tool—a “jig.” This device allows surgeons to drill all necessary pins through a single incision, significantly lowering the risk of bone fracture, bleeding, and infection compared to multiple cuts.
“In addition, the surgical grade stainless steel jig enables precise control of pin depth and angle, ensuring consistent and accurate placement,” said Prof. Liau.
The jig’s precision allows for pin insertion accurate to within 1mm and one degree. This heightened accuracy has also enabled surgeons to shorten the main central incision, further minimizing invasiveness.
A study validating the procedure, involving 102 patients using major robotic total knee arthroplasty systems, was published in the peer-reviewed journal Arthroplasty in 2025. A patent for the tool was successfully filed with the Intellectual Property Office of Singapore in October 2025, and it has been used on more than 200 patients in Singapore since 2023.
The innovation garnered recognition at the 2025 annual meeting of the American Association of Hip and Knee Surgeons in October, winning first prize at the Thai Hip and Knee Society annual meeting in December.
Prof. Liau emphasized the growing need for such tools as robotic total knee replacements become more prevalent, currently comprising 13% of all knee replacement procedures. “I’ve been using robotic technology for all my patients in the past 3½ years,” he said.
Prof. Liau also developed an artificial intelligence (AI) algorithm that integrates with the robot’s software to determine the optimal positioning of implants and cut surgery time by half.
The benefits are already being felt by patients. Madam Law Lai Tee, 72, a retired mother of two, underwent the new procedure in November 2025 after suffering from severe osteoarthritis that caused her left knee to curve 26 degrees inward—a condition affecting less than 0.5% of knee replacement patients. Before surgery, every step was painful and unstable.
“Today, my leg is straight again. The relief is not just in the knee, but knowing I didn’t have extra wounds to heal from and worry about,” she said.
Madam Nor Aini Abdullah, 85, who is older than the typical knee replacement patient (around 68), is now able to run errands independently after her procedure in October 2025.
“In sharing our techniques, inventions, and findings, we hope that more patients will benefit from safer and better knee replacements in future,” Prof. Liau said.
Madam Nor Aini Abdullah (left) underwent robotic total knee replacement surgery in October 2025 and Madam Law Lai Tee (right) underwent the same surgery in November 2025. She had severe valgus deformity from osteoarthritis.
