Background Despite the Motec metal-on-metal (MoM) total wrist arthroplasty (TWA) being among the most implanted and most reported implants, there remains concern about the articulation following the issues in hips, where early wear led to catastrophic failure.

Methods Explant analysis was undertaken on seven MoM Motec wrists, explanted for technical issues in the first 3 years postimplantation, at the macro-, micro-, and nanoscales.

Results Compared with unworn Motec implants, five of the explanted heads and five of the cups became smoother in vivo. The articulating surfaces of every explanted component had negative skewness. The articulating surfaces of the components did not show any of the major damage associated with hip implants but did demonstrate multidirectional scratches and dark marks mainly situated toward their equator. Four explants showed indentation marks on the rims of their cups and necks from component impingement. The nano- and macroscale observations suggested abrasive wear to be the dominant wear mechanism. Most components demonstrated evidence of self-polishing.

Conclusion In the short term, the MoM Motec TWA does not seem to be affected by the wear issues seen in failing MoM total hip replacements with all of the explanted Motec components remaining within manufacturing tolerances

I confirm that all authors have made a substantial contribution to the concept and design of this work and acquisition, analysis, and interpretation of data; that they have all been involved in the review process and approved the final version for submission. In addition, D.J.B. initiated and supervised the project. H.S.J. collected the clinical information from the departmental database. T.J. and G.K. performed the analysis of explanted material. All authors contributed to the writing of the manuscript.

There is no patient identifiable information or images within this submission and as a result informed consent has not been obtained.

This project has been registered with departmental research committee who felt that as it is a service evaluation, formal ethical approval is not required.

Received: 08 October 2023

Accepted: 23 January 2024

Article published online:
12 February 2024

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