Research Update October 2018

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.