Arthroplasty for Arthritis Research

Current Research

The public perception of joint replacement is that it is positively recognised as a life changing procedure and that it mainly occurs within the geriatric population. There is no doubt that joint replacement gives people a new lease of life, but the demographic is not entirely geriatric.

In recent years, there has been a cultural shift toward people wishing to pursue more active lifestyles well into old age. As a key factor in reducing obesity, heart disease and diabetes, maintaining an active lifestyle is to be encouraged. Being active, combined with better health care means that life expectancy has increased such that 18% of people in the UK (nearly 12 million) are now aged 65 years or older. By 2036 it is predicted that this figure will rise to 27%.

People will therefore often face having a hip replacement at a younger age and as people live longer and maintain their active lives, the number suffering from the debilitating effects of arthritis is increasing.

There is currently no guarantee that a new joint will be life lasting and so the length of time an implant can be made to last becomes an increasingly important issue.

There has never before been such a demand for joint replacement solutions that facilitate increased mobility and provide people of all ages with the ability to exercise their chosen lifestyles free of pain.

Research that can lead to design improvements and extended longevity of replacement joints is therefore of the utmost importance.

The primary focus of our research has been directed at improving implant bearing surface performance to achieve better outcomes for people facing joint replacement. Your donations have helped us to maintain research momentum to this end.

Implant materials used for hip replacements consist of different combinations of metal, ceramic and plastic. Current research indicates that all materials have their own specific problems, but some are more prone to fail than others. Overall the much publicised ‘metal on metal’ (MoM) joint is more prone to failure than other materials with 6.2% failing over 5 years, compared with 2.3% for ceramic on ceramic and 1.7% for metal on plastic.

One of our key research projects is to determine metal ion release from metal on metal articulating surfaces in cementless total hip arthroplasty. The research is concerned with adverse effects associated with the use of MoM bearing surfaces in hip replacement surgery. The project has a comprehensive focus aimed at determining the scale, the cause and the exact nature of the problems. Research is already revealing the levels of wear in different types of MoM bearings and helping to determine why some MoM hip replacements perform less well than others. Overall, this project will:

  • Enable the early identification of adverse problems
  • Highlight failure rates
  • Lead to design improvements and innovation for future hip replacement surgery
  • Create a resource to utilise in predicting appropriate implants for particular individual

We actively assist research projects focussed toward our aspiration of finding 'a hip for life'.

Currently we are supporting two musculoskeletal scientific research projects:

The London Project 

Professor Alister Hart, Anna Di Laura, and Johann Henckel. Royal National Orthopaedic Hospital NHS Trust and University College London.

Improving People’s Lifestyle: from Couch to...

The study will help inactive people understand the evidence-based, medical benefits and risks of taking exercise. Many individuals are concerned that exercise may cause or exacerbate painful musculoskeletal problems, but there is little known about the response of joints and muscles after exercise programs.The research is challenging, and seeks to better understand the benefits and risks from exercising on the walking (hip abductor) muscles and hip joints of physically inactive individuals who undergo exercise. MRI scans are used to evaluate the status of the hip joint and pelvic muscles.

Newcastle Project

Dr David Langton Director of ExplantLab Newcastle.

Developing a novel algorithm to predict the risk of metal-on-polyethylene joint replacement failure.

The immune response is critical to the clinical success of an implant, but this response, certainly from a genetic stance, is poorly understood. To date, scant research has examined the influence of immunogenetics on a patient's propensity to develop bone resorption (osteolysis) following implantation of a hip device. 

Over 160,000 NHS patients undergo hip and knee arthroplasty surgery each year. A number of these surgeries will fail, requiring costly and complex “revision surgery”.

Buccal swabs from patients are collected for DNA samples to perform next-generation sequencing on the samples, specifically for high-resolution typing of HLA Class I and II alleles. 

Identifying the genes associated with early failure, or long-term survival, of hip joints may allow clinicians to increase or reduce the intensity of postoperative surveillance protocols as appropriate.

Dr Langton commented that 'this has to be the way forward in the field of medical implants', He notes that it will be interesting to assess whether orthopaedics will be receptive to the use of DNA testing to direct treatment choice/plans in the future.

We continue to work with the Donaldson Arthritis Research Foundation (DARF) where research on bearing surface wear is the focal point.

We have supported research at The University of Southampton, National Centre for Advanced Tribology, which investigated metal debris and corrosion products released from CoCrMo hip replacements and correlate debris’ characteristics with origin and failure modes. The study focused mainly on debris originating from tapers and the cement-stem interface, which together with the wear at the bearing surfaces, significantly contribute to the failure of hip prostheses. We have worked with the University of Bath on a project with a principal aim of creating a repeatable Automated Recognition system for the diagnosis and Classification of Hip fractures (ARCHI).

Some Published Research


Evert Smith. Year of the Mask COVID-19 Challenges for Orthopaedic Surgery. Reconstructive Review, Journal of Joint Implant Surgery and Research Foundation (JISRF); 2020 

Clarke IC, Lazennec JA, Smith E, Donaldson TK.  Prosthetic Impingement in Total Hip Arthroplasty – the Trigger for Adverse Wear.  Open Journal of Orthopedics, 2020, 10, 321-358 


Koutalos AK, Toms AP, Cahir JG, Smith EJ.  Correlation of MARS MRI findings with cup position, metal ion levels and function in metal on metal total hip arthroplasty.  Hip Int 2019; HIPINT-D-17-00232R1 – August 2019 

AM Ebied, A Ebied, S Marei, E Smith.  Enhancing biology and providing structural support for acetabular reconstruction in single-stage revision for infection.  Journal of Orthopaedics and Traumatology 2019; 20:23.


Elsissy JG, Clarke IC, John A, Smith EJ Donaldson TK The significance of adverse 3rd-body wear damage in the failure of metal-on-metal bearings used in resurfacing and total-hip arthroplasty ACTA Scientific Orthopaedics, Vol 1, Issue 1, Oct 2018 

Metal on metal (MoM) tribology study is the first to report pits of typically 40 to 100 um or larger in resurfacing arthroplasty and also the first to confirm that hip impingement produces fatigue wear in cobalt (Co) chromium (Cr) components with release of large CoCr fragments consistent with sliding/impaction mechanisms in MoM heads. The metal fragments become trapped under the cup creating basal and polar microgrooves. This was a feature in both resurfacing and total hip arthroplasty retrieval specimens studied.

Donaldson TK, Smith E, Koutalos A, Lazennec JA, Clarke IC Adverse wear in MOM hip-arthroplasty related to the production of metal fragments at impingement sites. OJO Vol. 8, No. 10, October 2018

This study demonstrated that emerging technologies such as EOS x-ray analyses can reveal subtle changes in implant positioning using patient shifts in functional postures (sitting, standing, hyper-extension, etc.), and thereby assess impingement/subluxation risks in the clinical setting before failure occurs. 

This publication was also presented at the 13th European Hip Society Congress in The Hague in September 2018.

Antonios A Koutalos, Andoni P Toms, John G Cahir, Evert J Smith Correlation of MARS MRI findings with cup position, metal ion levels and function in metal on metal total hip arthroplasty HIPINT-D-17-00232R1 - Accepted for Publication 25 September 2018

The correlation between the severity of adverse reaction to metal debris (ARMD) on MRI with cup position, patient function and metal ion levels in a cohort of patients that received the ReCap/Magnum/Taperloc metal on metal (MoM) implant was studied. It was demonstrated that patients with MoM THA experience a high degree of ARMD and the disease severity correlates with cup position when evaluated with margin of safety angle. Close observation and adherence to MHRA guidelines is required for the best management of this group of patients. 


In collaboration with the University of Newcastle, an explant analysis of the Biomet Magnum ReCap was performed and the results have been published in Bone and Joint Research. The wear analysis revealed low taper wear, however wear from the articulating surface was found sufficient to cause implant failure. Close monitoring of patients with this device combination is recommended.

Scholes SC, Hunt BJ, Richardson VM, Langton DJ, Smith E, Joyce TJ Explant analysis of the Biomet Magnum/ReCap metal-on-metal hip joint Bone Joint Res 2017;6:113-122

Metal on metal Poster Presentations:

Smith EJ, Koutalos A, Clarke IC
Birmingham Hip Resurfacing Arthroplasty and The Risk of Small Heads 
Orthopaedic Research Society
San Diego - March 2017

Koutalos A, Smith EJ, Kourtis A, Scholes S, Joyce T, Clarke IC 
Midterm Results of Recap/Magnum Metal on Metal Total Hip Arthroplasty with Retrieval Analysis of Failed Implants. Introduction of Margin of Safety Angle. 
Orthopaedic Research Society
San Diego - March 2017

IC Clarke, T Halim, J Shelton, A Koutalos, EJ Smith, TK Donaldson 
Simulating Edge Wear of MoM in Subluxing Patient
Poster No. 1023 
Orthopaedic Research Society 
San Diego - March 2017


Work on an algorithm to assess edge loading undertaken in collaboration with The Donaldson Arthritis Research Foundation has been ongoing. A new margin of safety (MOS) algorithm was developed from simulator studies that can predict the risk of edge loading and subsequent metal wear in MoM implants. The MOS algorithm has been published and is applied in our research.

Clarke I, Donaldson T, Savisaar C, Bowsher JG. New algorithm to accurately depict cup wear-patterns with margin-of-safety in clinical and simulator studies. 28th International Society for Technology in Arthroplasty (ISTA) Annual Congress, 2015. Vienna, Austria, October 2015

An abstract on the midterm results of the ReCap Magnum metal on metal total hip arthroplasty was presented at the 12th European Hip Society Congress in 2016 and was published in Hip International Journal. This was later followed by acceptance of the research for publication also by Hip International. The mid-term results of the ReCap Magnum were found to be modest compared to other bearing articulations, but it was noted that this combination suffers from the same class specific problems as other metal on metal arthroplasties. Concern was raised regarding revisions already performed for ARMD in this study, as well as the high number of positive MARS MRI in asymptomatic patients. It is considered by the authors that the failure rate will increase. The Hip International publication utilised the MOS algorithm.

Koutalos A, Kourtis A, Clarke I, Smith E. Midterm Results of ReCap/Magnum Metal-on-Metal Total Hip Arthroplasty with Mean follow-up of 7.1 years. Hip Int 2016; 26 (Suppl 2): S3-S55 DOI: 10.5301/hipint.5000450 Page 11 & 12

Koutalos AK, Kourtis A, Clarke IC, Smith EJ. Mid-term results of Recap/Magnum/Taperloc metal-on-metal total hip arthroplasty with mean follow-up of 7.1 years. Hip Int 2016; 00 (00): 000-000 DOI: 10.5301/hipint.5000454


A tribology explant analysis of the Biomet ReCap Magnum metal-on-metal implant was submitted and accepted for abstract presentation at the Institute of Mechanical Engineers:

Scholes SC, Smith E, Joyce TJ. Explant analysis of the Biomet Magnum/ReCap metal-on-metal hip joint. Institute of Mechanical Engineers 2015

A Poster Presentation comparing ceramic-on-ceramic and metal-on-metal retrieval was successful at the 2015 British Hip Society meeting:

Clarke IC, Joyce TJ, Scholes S, Smith E, Grijalva C. 
Comparison of CoC and MoM THA retrievals - successful at three decades
British Hip Society
London - March 2015


A publication on femoral offset was published in Hip International Journal:

James R. Berstock, Adrian M. Hughes, Amy M. Lindh, Evert J. Smith. A radiographic comparison of femoral offset after cemented and cementless total hip arthroplasty Hip Int. 2014; 24(6): 582 – 586

A series of published abstracts were presented at the 2014, 11th European Hip Society Congress and published in Hip International Journal. This research discussed cup impingement, wear damage in hip resurfacing and metal bearing wear from a hip simulator study, corrosion with 28mm metal-on-metal bearings and the five year results of the Exceed ABT 15 degree face-changing acetabular cup for the treatment of the dysplastic hip:

Clarke IC, Smith E, Donaldson TK, Bowsher JG, Savisaar C. Cup impingement and wear damage with hip resurfacing is similar to that in retrieved total hip arthroplasty. Hip Int. 2014; 24 (5): 491 pp.513-4

John A, Clarke IC, Smith E, Donaldson TK, Savisaar C, Bowsher JG. Severe Metal-on-Metal bearing wear triggered by 3rd body metal particulates in hip simulator study. Hip Int. 2014; 24 (5): 491 pp.540

Clarke IC, John A , Smith E, Donaldson TK, Bowsher JG, Savisaar C. Corrosion assessment of 12-14 European tapers used with 28mm metal-on-metal bearings. Hip Int. 2014; 24 (5): 491 pp518

Veettil MP, Ward AJ, Smith EJ. Cementless Acetabular Reconstruction in Dysplastic Hips: Five year results of Total hip Arthroplasty using the 15 degrees face changing cup. Hip Int 2014; 24 (5): 491 pp.537-8

International Conference Presentations

Charity Director, Evert Smith, continues to disseminate knowledge at international forums as a regular invited faculty member. Some presentations between 2017 and 2021:

Keynote Lecture: Seddon Society, London.
A synopsis of 20 years of Orthopaedic Progress
Webinar – September 2020 
A synopsis of 20 years of Orthopaedic Progress
Webinar – September 2020
Programme Co-organiser
The Bristol Hip Meeting
Bristol - November 2019
Course Chair and Coordinator
EEMEA Cementless Hip Symposium
Amsterdam – June 2019 
Professor Ian Clarke - Donaldson Arthritis Research Foundation
Japanese Arthroplasty Conference
One-hour address 'Trunnionosis vs Impingement'
Tokyo - February 2019

Mayo Arthroplasty Conference
Extensive Exposure of the Hip – Tips and Tricks
Westport - April 2018

1st International Hip & Knee Arthroplasty Symposium
Cemented or uncemented Total Hip Arthroplasty – How to decide?
Larissa - April 2018

Thessaloniki University - Visiting Academic Lecture Programme
A fatuous argument - Cemented or Cementless THA
Larissa - April 2018

Thessaloniki University - Visiting Academic Lecture Programme
From the witness box - Metal on Metal
Larissa - April 2018

Thessaloniki University - Visiting Academic Lecture Programme
Exposures of the hip - Tips and Tricks
Larissa - April 2018

18th EFORT Congress
When to Revise Metal on Metal Bearings?
Vienna – June 2018

6th International GOSICON
Exceed ABT
Delhi - September 2018

6th International GOSICON
Approaches to the Hip - What's New?
Delhi - September 2018

6th International GOSICON
New Trends in Acetabular Revision
Delhi - September 2018

Karnataka Orthopaedic Association
Approaches to the Hip - What's New?
Bengaluru - September 2018

13th EHS Congress
Early developments and results of RA
The Hague - September 2018

Ian C. Clarke, Evert J. Smith, Thomas K. Donaldson
Adverse MOM wear mechanisms are triggered by release of large metal particles during MOM impingement episodes
European Hip Society 13th Congress
No. 271 Oral Presentation
Session ID: O23 Metal ion release & tribology
The Hague - 21.09.2018

"I suffer with Lupus, a complex and unpredictable disease that can affect many parts of the body and present many different symptoms. Returning from a climbing trip in March 2011, my left hip was very sore, but I put it down to a strain. Although Lupus can cause connective tissue issues, I hadn’t had bone problems before. By May the same year, I was barely able to walk and unable to sleep, for the most excruciating pain.

Later, an MRI scan revealed a huge fracture through my femoral head. I had two choices: take a bore into the femoral head and graft from my tibia, and hope it would regrow bone marrow followed by 9 months on crutches – with no guarantee of success. Or have a total hip replacement. As a very active and sporty 29 year old, it was a simple choice.

Two weeks later, I had a brand new ceramic hip, and was back on the climbing wall 5 weeks after that. I have religiously performed my physiotherapy, and continue to cycle, climb and do Pilates. It’s the best thing to have happened and I believe it’s actually stronger than my right hip. Without doubt, my life – could have been very different without it."

Jess Ellis, (31) Arthroplasty Patient