Revision of partial to total knee arthroplasty using robotic assistance

Listen to Simon and Amy discuss the paper 'Revision of partial to total knee arthroplasty using robotic assistance' published in the March 2026 issue of Bone & Joint Open.

Click here to read the paper.

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Transcript

[00:00:00] Welcome back to another episode of AI Talks with Bone & Joint from the publishers of Bone & Joint Open. Today, we're discussing the paper "Revision of partial to total knee arthroplasty using robotic assistance," published in March 2026 by B Ingelaere and F Hardeman. I'm Simon, and I'm here with my co-host, Amy.

Hello, everyone. This study explores the use of robotic assistance in transitioning from partial knee arthroplasty to total knee arthroplasty. Simon, could you provide some context for this research?

Of course. Knee osteoarthritis is a significant cause of pain and disability around the globe. There are various surgical interventions available, and while partial knee arthroplasty is favored for isolated compartment degeneration due to its benefits of preserving native joint anatomy and faster recovery, it does have a higher revision rate compared to total knee arthroplasty.

The higher revision rate really drives home the need for this research. According to the study, approximately 60% of partial knee arthroplasties with poor functional scores are [00:01:00] revised compared to just 10% for total knee arthroplasties. The researchers aim to see if robotic assistance could improve outcomes when partial knee arthroplasties need to be converted to total knee arthroplasties.

This was a retrospective cohort study involving 23 patients who underwent robotic-assisted conversion from partial to total knee arthroplasty. They employed the ROSA Knee System, which is designed to enhance implant positioning and alignment accuracy. All procedures were performed by a single high-volume knee surgeon, ensuring consistency in technique.

They also utilized the Persona Total Knee System and underscored the significance of anatomical landmark registration. By registering these landmarks directly on the prosthesis in situ before explantation, they could accurately identify joint line alterations and component malalignments. Indeed, and they adhered to the principles of inverse kinematic alignment, aiming to restore the native joint line and knee kinematics.

Now let's delve into the results. Amy, could you share [00:02:00] some of the key outcomes? The Oxford Knee Score saw a substantial improvement from a mean of 17.2 preoperatively to 40.0 at 12 months postoperatively. Pain scores on the visual analog scale decreased from a mean of 6.7 to 1.6. Quite impressive. They also noted that all cases were successfully registered with the robot and completed without the need for femoral components or augments, except in one case due to extensive cystic bone loss.

That really demonstrates the viability of the method, doesn't it? Absolutely. As for radiological accuracy, they found that the mean absolute error between planned and achieved alignment was minimal for the medial proximal tibial angle and lateral distal femoral angle, though the hip-knee-ankle angle showed greater variability.

However, these deviations didn't significantly affect clinical outcomes. Right. One noteworthy aspect they mentioned is that these small deviations in mechanical alignment are often clinically acceptable, particularly [00:03:00] under kinematic or inverse kinematic alignment strategies. This underscores the potential of robotic technology to optimize complex surgeries.

The study certainly indicates that robotic assistance can enhance surgical reproducibility and lead to satisfactory early clinical outcomes. As we conclude, Simon, what are the key takeaways for our listeners?

In summary, this study demonstrates that robotic-assisted conversion from partial to total knee arthroplasty is feasible, enhances clinical outcomes, and achieves high radiological accuracy in component positioning. It marks a significant advance in knee revision surgery, potentially offering better alignment and functional restoration.

Thank you for tuning in, everyone. Do check out the full paper titled "Revision of partial to total knee arthroplasty using robotic assistance" in Bone & Joint Open. Until next time.