A groundbreaking study led by Associate Professor Simon Young from WaipapaTaumata Rau, University of Auckland, reveals that a novel AI-assisted knee-replacement surgery improves outcomes for patients with naturally bowed legs. Published in the Journal of Arthroplasty, the research highlights how functional alignment, guided by AI, can tailor surgeries to individual anatomies for better results.

Revolutionizing Knee Replacements
Traditional knee-replacement surgeries assume the leg is straight, which may not suit patients whose knees have always had a curved alignment. This mismatch can lead to dissatisfaction in about 20% of cases. To address this, Young and his team developed an AI algorithm that works with a surgical robot to analyze thousands of potential component placements, selecting the optimal position for each patient’s unique anatomy.

The study involved 244 patients, half of whom received conventional surgery while the other half underwent the new functionally aligned procedure. Over two years, both groups showed positive outcomes, but patients with bowed legs reported significantly better results with the AI-assisted method.

How the AI System Works
The AI software uses pre-operative imaging to map the patient’s knee alignment and surrounding soft tissue. It then evaluates 20,000–25,000 possible positions for the replacement components, ranking them based on suitability. Surgeons review these options and select the best fit.

“For people with bowed legs, standard knee replacements may not work as well,” explains Young, an orthopedic surgeon at Health New Zealand Te Whatu Ora Waitematā. “Our approach ensures the new knee matches their natural alignment, which they’ve had their entire lives.”

Future Implications
The findings suggest that surgeons should consider a patient’s natural leg shape when planning knee replacements. Young has also developed an app to help orthopedic surgeons in New Zealand, Australia, and Asia adopt this technique.
This innovation marks a significant step toward personalized knee surgery, offering hope for improved recovery and satisfaction, particularly for the 30% of the population with bowed legs due to genetics or conditions like arthritis.