Hip Orthopaedics Research

This section contains information about Evert’s research.

Test tubes and lab equipment

Evert’s work as an orthopaedic surgeon is inter-related with a research programme which is undertaken in collaboration with UK Universities and overseas institutions. This is supported by regular publications in medical journals and books.

His research and work as a surgeon is carried forward on the international stage where knowledge is shared, issues are debated and practical workshops and demonstrations are given.

Some Recent Published Research


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

Several metal on metal Poster Presentations were achieved:

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

Evert continues to disseminate knowledge at international forums as a regular invited faculty member. Some presentations during 2017 and 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


18thEFORT 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


FDA Grant Award

The orthopaedic fraternity has been concerned for some considerable time about patient response to metal debris and higher than expected failure rates of metal on metal (MoM) hip replacements and resurfacing hip arthroplasties. This is now widely documented in national joint registries and orthopaedic literature.

The necessity for research in this field was acknowledged by the United States Government Food and Drug Association (FDA) when the opportunity was offered for appropriate interested institutions to tender for a Federal research grant.

A collaboration of internationally renowned surgeons led by Professor Ian Clarke of the Donaldson Arthritis Research Foundation (DARF) in the USA, submitted a proposal for an implant retrieval and a tribology study. Those involved were Evert Smith, Thomas Donaldson, Michelle Burgitt, Don Lucia, William Long, Edward McPherson, Christopher Peters, Jean Yves Lazennec, Andrea Stark, Allen Turnbull, Alun John, Duncan Whitwell. 

This ambitious and competitive proposal was rewarded with a contract for the analysis and validation of wear and corrosion performance of MoM hip explants.

As a Member of the Advisory Group for DARF, Evert's involvement in this proposal resulted from his reputation and expertise as a complex primary and revision hip surgeon, as Bearing Surface Evaluator and Regional Clinical Co-ordinator for the National Joint Registry, as well as his work for the UK Government’s Orthopaedic Data Evaluation Panel where he evaluates the national performance of hip prostheses.

Clinical experience measuring the wear of bearing surfaces has provided an understanding of the function of high-density polyethylene liners in total hip replacements. There is also a sound scientific understanding of the wear performances of ceramic on ceramic bearing surfaces. Wear rates of MoM bearing surfaces have been simulated in laboratories, but at the time, there had been few comparable studies for MoM wear rates in patients with resurfacing hip arthroplasties or large head MoM total hip replacements.

This collaboration resulted in some groundbreaking research which has been disseminated at many orthopaedic seminars throughout the world and has achieved publication in the orthopaedic literature. In addition, a predictive logarithm capable of predicting the risk of early failure has been developed.