In vivo reduction of biofilm seeded on orthopaedic implants

Listen to Simon and Amy discuss the paper 'In vivo reduction of biofilm seeded on orthopaedic implants' published in the December 2024 issue of Bone & Joint Research.

Click here to read the paper.

Be the first to know when the next episode is live! Follow our social media accounts, @BoneJointPortal and @BoneJointRes on X, and @bonejointres on Instagram for updates!

Transcript

[00:00:00] Welcome back to another episode of AI Talks with Bone & Joint brought to you by the publishers of Bone & Joint Research. Today we're discussing the paper 'In vivo reduction of biofilm seeded on orthopaedic implants' published in December 2024 by authors E. Cordero García-Galán, M. Medel-Plaza, J. J. Pozo-Kreilinger, H. Sarnago, O. Lucía, A. Rico-Nieto, J. Esteban, and E. Gomez-Barrena. 

I am Simon and I am joined by my co-host, Amy. 

Hello everyone. I'm looking forward to delving into this important study on biofilms and orthopaedic implants. The research focuses on combating implant infections using electromagnetic induction heating. It's a critical topic for anyone involved in orthopaedic surgery. 

Indeed, Amy. Implant infections affect around 2% of all orthopaedic surgeries and are notoriously difficult to treat due to [00:01:00] biofilms, essentially bacterial communities that adhere to the implant surface and resist antibiotics. These biofilms protect bacteria like Staphylococcus aureus, making them harder for antibiotics and the immune system to eliminate. The study we're discussing today looked at using electromagnetic induction heating to target these biofilms directly on implants. 

Let's break it down then. The researchers used titanium screws coated with Staphylococcus aureus biofilm, which were implanted into the knees of New Zealand giant rabbits. The novelty here is the induction heating technique. Amy, can you explain how it functions? 

The team developed a Portable Disinfection System based on Induction Heating, or PDSIH. This system heats the metallic surface of the implanted screw to 70 degree Celsius. For three and a half minutes without physical contact, aiming to eradicate the biofilm, but avoiding damage to surrounding tissues.

A remarkable feat of engineering. [00:02:00] To ensure the process's safety, heating was only applied to one knee in each rabbit while the other knees served as a control. This helped isolate the effects of the induction heating from other variables.

The researchers measured the bacterial load on the screws and observed the extent of bone necrosis. They used sonication to dislodge the bacteria from the screws and then conducted microscopic examinations on the femoral bone. The results were promising. They observed a significant reduction in bacterial load, with a median decrease of 0.75 Log10 colony-forming units per milliliter. 

Importantly, the technique didn't cause a significant increase in bone necrosis. The width of necrosis in treated knees range from zero to 650 micrometers, which is minimal and comparable to normal surgical effects like drilling.

This is a crucial finding since one major concern with thermal treatments is unintentional tissue damage. Their assessment over several time points, 24, 48 and [00:03:00] 96 hours showed consistent outcomes, reinforcing the reliability of the results. 

Indeed, Simon. It is worth noting that while the reduction in bacterial load was modest compared to previous studies using induction heating, the technique holds great promise. Future research might combine this with other methods, like mechanical cleaning and antibiotics to enhance its effectiveness. 

That's a valid point, Amy. Before we conclude, let's highlight the key takeaways. Induction heating shows considerable promise for reducing biofilm on orthopaedic implants with minimal bone necrosis. This could be transformative in managing prosthetic joint infections. 

Absolutely, Simon. This research opens new avenues for improving debridement, antibiotics, and implant retention protocols, potentially enhancing recovery rates for patients. It's an exciting development in orthopaedic surgery and infection control.

Thank you to our audience for tuning into this episode of AI [00:04:00] Talks with Bone & Joint. Stay tuned for more discussions on groundbreaking research in orthopaedic surgery and beyond. 

Goodbye everyone, and do follow the Bone & Joint Research social media channels for more updates.