Research carried out at the Centre has uncovered critical safety issues in hip implant design, quality control, and data reporting. The team identified previously undetected causes of implant failure — including size mismatch, poor-quality generic implants, and corrosion in modular designs — leading to significant patient harm and financial costs to the NHS. Through large-scale data analysis and collaboration with national regulators, the work has not only corrected gaps in national implant registries but also influenced global standards for implant safety. The findings continue to guide improvements in implant design, surgical practice, and regulatory oversight.

• REF 2014 Impact Case Study: Changes to health policy and medical device regulation following analysis of metal-on-metal hip replacement
• Hip replacements: Changes to health policy and regulation
• National recognition of research at RNOH: making orthopaedic implants safer (p. 32-33)

Also, the research work has significantly improved the safety and management of metal-on-metal (MOM) hip replacements worldwide. The team has identified how these implants release harmful metal ions into the bloodstream, causing tissue damage. Their work led to the development of key diagnostic tools, including a blood metal ion threshold (7 ppb) and the MARS MRI protocol, now used routinely in NHS hospitals. This research has shaped global regulatory guidelines, prompted the recall of faulty implants, and supported legal claims by affected patients. A global retrieval programme has analysed thousands of failed implants to understand causes of failure. As a result, patients now receive safer, ceramic-based replacements, improving outcomes and quality of life. The research has also introduced stricter approval standards for orthopaedic implants to prevent similar device failures in the future.

• REF 2021 Impact Case Study: Orthopaedic implant analysis changed which joint implants were used and how they are monitored
• Making joint implants safer by identifying causes of previous failures
• Shaping the future of hip replacement surgery
• RNOH Spine Research: UCL and NSO: Giving children with scoliosis a new lease of life with innovative spine implants

Our work focuses on five key areas of implant research:

1. 3D-printed implant research

We are a global leader in studying 3D-printed implants, particularly for complex joint reconstructions. Using advanced imaging and analysis techniques, we investigate how these implants bond with bone, identify structural defects, and explore why they may offer improved outcomes for patients. Our work is also pioneering new ways to monitor these implants through blood-based biomarkers such as titanium levels.

“3D-printed implants offer new possibilities for complex joint surgery. We use advanced imaging to study how they bond with bone and ensure they perform safely over time” –  Dr Anna Di Laura

2. Growing rod technologies

The Centre is a hub for research into magnetically controlled growing rods, used to treat spinal and limb deformities in children. Through detailed retrieval analysis, imaging, and mechanical testing, we study how these devices behave inside the body over time. Our goal is to improve their reliability, reduce the need for early revision surgeries, and support better long-term outcomes for young patients.

“Over the past eight years, our research team has analysed retrieved MCGRs to better understand how they perform in patients; indeed, we now have the largest catalogue of retrieved MCGRs anywhere in the world” – Prof Alister Hart

3. Evaluating new implants

As new implants are introduced into clinical practice, we conduct real-world performance studies, combining lab testing with analysis of retrieved devices and clinical outcomes. This allows us to detect early signs of failure or complications that may not appear in pre-clinical testing, helping ensure that new designs meet the highest standards of safety and effectiveness.

“We study how new implants perform in real patients, using imaging and retrieval analysis to catch potential issues early and support safer surgical choices.”

4. Developing blood titanium biomarkers

We are building on our pioneering work in cobalt and chromium blood biomarkers to investigate blood titanium levels as a non-invasive biomarker for implant health. This work could allow clinicians to detect early signs of implant wear or failure before symptoms appear, offering a powerful new tool for patient monitoring and safety.

“Blood-based biomarkers could revolutionise how we monitor orthopaedic implants — making it easier to catch issues before they become problems.” - Johann Henckel

5. Decommissioning legacy retrieval programmes

As part of our evolving priorities, the Centre has responsibly concluded a long-running implant retrieval programme that played a vital role in clinical, regulatory, and legal settings. With its objectives successfully achieved, this transition allows us to focus on new areas of research, drawing on the programme’s legacy of high-impact insights and patient safety outcomes.

“Our past retrieval work shaped global implant safety standards. As we move forward, we’re applying those lessons to today’s technologies and tomorrow’s challenges.” – Prof John Skinner

Our work is grounded in a simple goal: to help patients move better, recover faster, and live with fewer complications. By understanding how implants perform over time and why they sometimes fail, we’re improving care for current patients and developing safer, more personalised solutions for the future.

Our insights have helped:

• Extend the lifespan of hip and knee implants
• Reduce revision surgeries in children
• Improve the reliability of 3D-printed and growing rod implants
• Shape clinical guidance and regulatory frameworks in the UK and beyond

We’re a collaborative, multidisciplinary team of engineers, clinicians, scientists and imaging experts. Our research combines hands-on analysis of real implants with state-of-the-art tools, including:

• Micro-CT and laser scanning
• Advanced imaging and retrieval techniques
• Blood metal ion testing
• Statistical modelling and performance evaluation

We also work closely with industry partners, regulatory bodies, and surgical teams to ensure that innovation is backed by evidence and translated into real-world impact.

“There’s something powerful about combining lab science with real patient data. It allows us to make discoveries that genuinely change practice.” –  Prof Alister Hart

The future of implant science lies in personalised, data-driven, and non-invasive care. Our upcoming priorities include:

• Establishing blood titanium testing as a reliable early-warning tool
• Expanding the clinical use of 3D-printed implants for complex cases
• Improving our understanding of growing rod designs to reduce complications and repeat surgeries
• Tracking the real-world performance of new implants as they’re adopted

We’re proud to help lead these efforts at one of the world’s only centres to unite retrieval science, imaging, and materials research in a single hub. From improving implant designs to informing international safety guidance, our research has global relevance but it always starts with a single question: what will make life better for the person receiving this implant? Johann Henckel, orthopaedic surgeon at RNOH and research leader, explains more in the Q&A below.

In Conversation: Johann Henckel on Implant Science

Alongside clinical work, Johann leads research into imaging software that helps us better understand the biomechanics of the lower limb musculoskeletal system. His focus includes the use of advanced surgical technologies in hip and knee joint replacement, with specialist expertise in robotics and computer-assisted surgery. As both a clinician and researcher, Johann plays a vital role in bridging surgical practice with innovation and implant safety.

What does the Implant Science Centre do in simple terms?

We study how orthopaedic implants, like hips, knees, and growing rods, perform inside the body. Our team investigates why some devices last longer than others, and how we can improve designs to make them safer, more effective, and longer-lasting.

How do you carry out this kind of research?

We use advanced imaging and analysis tools, like micro-CT scans and blood tests, to examine both new implants and those removed from patients. We’re uncommon in bringing together diverse specialisms, engineering, materials science, and real-world clinical insight, to do this.

What’s the benefit for patients?

Better implants mean fewer complications, fewer revision surgeries, and longer-lasting results. For children, we’re working to make growing rod implants more reliable. We’re also developing non-invasive blood tests, like titanium level monitoring, that could help spot problems early, before symptoms appear.

What’s surprised you in this field?

How well 3D-printed implants can integrate with bone. Also, how much insight we can get from analysing implants after they’ve been inside real people. Sometimes we find tiny manufacturing flaws that could affect performance. It’s small details that can make a big difference.

What’s next for your team?

We’re focusing on improving monitoring tools, especially around blood titanium levels, and continuing our work with 3D-printed and paediatric implants. We’re also shifting more of our attention to evaluating newly introduced devices, making sure that innovation always goes hand in hand with safety.

What motivates you personally in this work?

It’s incredibly rewarding to know that our research directly contributes to better outcomes for patients. We work as a team, surgeons, engineers, medical physicists and scientists, each bringing something different to the table. It’s that mix of perspectives that makes this work so powerful.

RNOH Joint Reconstruction Unit (JRU)

• Professor John Skinner
• Mr John Stammers
• Mr Albert Ngu
• Mr Shiraz Sabah

RNOH Adult and Paediatric Limb Reconstruction Unit

• Mr Peter R Calder
• Mr Jonathan Wright

RNOH Spinal Surgical Unit

• Mr Hanny Anwar
• Mr Alexander Gibson
• Mr Sean Molloy
• Mr Roozbeh Shafafy

RNOH Anaesthesia, Intensive Care, Chronic Pain Management

• Dr Rachel Baumber
• Dr Roxaneh Zarnegar

RNOH Radiology

• Dr Anastasia Fotiadou

RNOH Rheumatology

• Dr Gayatri Mittal

RNOH Physiotherapy Unit

• Ms Anju Jaggi
• Ms Katie Monnington
• Ms Jessica Woodrow

RNOH Research and Innovation Centre (RIC)

• Ms Ira Jakupovic