By: 22 June 2018
Considering SIP factors in implant failure

A review of the London Implant Retrieval Centre 10-year anniversary meeting, held at the Royal Society of Medicine, London, on 20 April 2018, with its conveners Dr Harry Hothi, Prof John Skinner and Prof Alister Hart

The London Implant Retrieval Centre’s meeting at the RSM marked over 10 years of collaborative work between surgeons, engineers, radiologists, scientists, patients and others to better understand why spine, hip and knee implants fail. We were joined by an international faculty from hospitals and research institutions in Finland, Germany, Switzerland and the US, as well collaborators from across the UK.

A strong theme throughout the day was of the multifactorial nature of failures and the need to consider surgeon, implant and patient (SIP) factors in a holistic approach. This was supported by lively discussion from the multi-disciplinary audience about which of these SIP factors was the most prevalent.

The role of pre-revision imaging in improving patient outcome after surgery is clear and now essential in aiding retrieval analysis; from 3D-CT imaging to fully understand component positioning to MARS-MR imaging to assess soft tissue damage.

Talks on corrosion in hip, spine and even dental implants highlighted that implant corrosion is a common finding on retrieved components; being able to discern when this becomes clinically significant is essential. Risk factors such as the use of TMZF, metal alloy mismatches and dual-taper femoral stems all help surgeons identify which patients to monitor more closely.

Learning from implant failures is key in the innovation of new designs and we heard of the improvements that are being made to pre-clinical simulators. A safe and stepwise approach to introducing these new devices for use in patients is necessary and being championed by Beyond Compliance (BC) in the UK. BC views analysis of retrieved implants as a key requirement for their assessment process; this was a view shared by the audience and faculty and also by the industry speakers from Zimmer-Biomet, DePuy Synthes and JRI, who all supported an industry-led funding model to support this work.

 

Polling of the audience of surgeons, engineers and industry representatives revealed a consensus that:

  • Retrieval information is more useful when combined with imaging, registry data and infection data.
  • Retrieved implants that are registered with Beyond Compliance should be sent to an independent retrieval centre for storage and analysis.
  • Retrieval information helps monitoring of well-functioning implants such as modular-neck hips.
  • Retrieval information helps manufacturers design better implants.

 

In the past 10 years, the London Implant Retrieval Centre has collected over 9,000 retrieved components from 29 countries and published over 130 peer-reviewed papers with 200 co-authors; our work has been cited over 3,000 times. We look forward to the next 10 years, which we hope will see continued improvements in the management of orthopaedic patients and also continued innovation of orthopaedic technology in a safe and controlled way.

Many thanks to Jai Mistry and his team for helping to organise the meeting and thank you to all that attended and helped to make it a successful day.

 

Dr Harry Hothi, Prof John Skinner and Prof Alister Hart

Directors, London Implant Retrieval Centre

www.LIRC.co.uk