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. 2025 Apr 17;145(1):249.
doi: 10.1007/s00402-025-05869-x.

Metal-on-metal arthroplasty, cobalt toxicity, and development of cognitive impairment: a systematic review

Mostafa Beshr  1 , Phyo Kyaw Myint  2 , Iain Rankin  3 , Cameron Stephen  4 , Adithya Varma  3 , Luke Farrow  3   2
Affiliations

Metal-on-metal arthroplasty, cobalt toxicity, and development of cognitive impairment: a systematic review

Mostafa Beshr et al. Arch Orthop Trauma Surg. .

Abstract

Background: Neurological dysfunction secondary to cobalt toxicity has been described as a potential complication of metal on metal (MoM) arthroplasty, however, to date the full extent of this association remains unclear. Currently, no national guideline on the management or follow-up of MoM arthroplasty patients recommends monitoring for potential insidious cognitive decline or long term consequences. The aim of this study was to summarise the available evidence regarding the relationship between MoM arthroplasty associated cobalt toxicity and cognitive impairment (CI).

Methods: A systematic review of literature describing cobalt concentrations associated with neurocognitive symptoms in patients with MoM implants was undertaken. The study was registered with PROSPERO on the 18th July 2023 (CRD42023436880), in concordance with PRISMA guidelines. The Downs and Black Checklist assessed the risk of bias and evidence quality. Primary outcomes were reports of CI and blood cobalt concentration at presentation and following revision surgery.

Results: Of 361 records identified, 15 relevant publications were included. Downs and Black Checklist assessment revealed that few high-quality studies currently exist. A clear association between MoM arthroplasty and CI, across varied follow up periods, was described by all 15 studies. Mean serum cobalt concentrations at presentation of CI were 9.75ug- 625ug, however no threshold cobalt concentration was identified. Over 85% of papers which recorded post-revision outcomes reported partial, if not complete, resolution of pre-operative CI following revision surgery.

Conclusions: This study provides the first robust systematic examination of the evidence surrounding metal on metal arthroplasty, cobalt toxicity, and potential CI. While further research is required to evaluate the exact nature of this relationship, our findings suggest that national and international guidelines should highlight the possible cognitive dysfunction secondary to MoM arthroplasty associated cobalt toxicity, including the need for routine assessment of cognitive function in those who received MoM implants.

Keywords: Arthroplasty; Cobalt toxicity; Cognitive; Dementia; Metal.

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Conflict of interest statement

Declarations. Competing interests: The authors declare no competing interests.

References

    1. Knight SR, Aujla R, Biswas SP (2011) Total hip Arthroplasty-over 100 years of operative history. Orthop Rev. 3(2)
    1. Bozic KJ, Kurtz S, Lau E, Ong K, Chiu V, Vail TP, Rubash HE, Berry DJ (2009) The epidemiology of bearing surface usage in total hip arthroplasty in the united States. JBJS 91(7):1614–1620 - DOI
    1. University of Bristol Phasing out all-metal hip replacements, https://www.bristol.ac.uk/research/impact/phasing-out-all-metal-hip-repl... ; [Accessed 9th September 2024]
    1. Fabi D, Levine B, Paprosky W, Della Valle C, Sporer S, Klein G, Levine H, Hartzband M (2012) Metal-on-metal total hip arthroplasty: causes and high incidence of early failure. Orthopedics 35(7):e1009–e1016 - DOI - PubMed
    1. Brent J, Devlin JJ Dilemmas about the toxicological consequences of metal-on-metal hip prostheses– what we do and do not know, and what we should do? Clin Toxicol 2013 51 195–198. ( https://doi.org/10.3109/15563650.2013.784326 )

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