University of Oulu

Nousiainen, T., Palosaari, S., Peräniemi, S. et al. Retention of metals in periprosthetic tissues of patients with metal-on-metal total hip arthroplasty is reflected in the synovial fluid to blood cobalt transfer ratio in the presence of a pseudotumour. BMC Musculoskelet Disord 21, 610 (2020).

Retention of metals in periprosthetic tissues of patients with metal-on-metal total hip arthroplasty is reflected in the synovial fluid to blood cobalt transfer ratio in the presence of a pseudotumour

Saved in:
Author: Nousiainen, Tomi1,2; Palosaari, Sanna1; Peräniemi, Sirpa3;
Organizations: 1Medical Faculty, Cancer and Translational Medicine Research Unit, University of Oulu and Medical Research Center, Oulu University Hospital, P.O. Box 5000, 90014, Oulu, Finland
2Division of Orthopaedic Surgery, Oulu University Hospital, Oulu, Finland
3University of Eastern Finland, School of Pharmacy, P.O. Box 1627, 70210, Kuopio, Finland
4Department of Environmental and Biological Sciences, University of Eastern Finland, P.O. Box 1627, 70210, Kuopio, Finland
5Division of Radiology, Oulu University Hospital, Oulu, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 1.4 MB)
Persistent link:
Language: English
Published: Springer Nature, 2020
Publish Date: 2020-11-20


Background: Modern metal-on-metal (MOM) arthroplasties were performed for over a decade before alarming reports of adverse metal reactions dramatically reduced their use. Failures are seen more often with high-wearing implants, but also well-positioned components with more favourable wear patterns can cause problems. There are no specific clinical indicators that could help us to predict the prognosis of these implants. For this reason, we still need more information on the effect of underlying factors that contribute to this process.

Methods: In this prospective cohort study, we investigated how cup orientation and type of pseudotumour determined by the Hart classification effect the distribution of metals in blood, synovial fluid and tissues surrounding the metal-on-metal hip prosthesis in revision surgery patients. One thousand two hundred twenty-nine metal-on-metal hip patients were screened and of those, 60 patients that had a revision surgery due to adverse metal reaction were included. Whole blood, synovial fluid and synovial/pseudotumour tissue samples were analysed for metal ion concentrations (Co, Cr, Mo and Ti).

Results: The lowest metal concentrations were found when both cup anteversion and inclination were optimal, and the highest when both were suboptimal. Suboptimal anteversion alone raised Cr-ion concentrations more than suboptimal inclination. The concentrations of metals in blood, synovial fluid or synovial soft tissue were the same in patients with and without a pseudotumour, but the relative transfer percentage of cobalt from synovial fluid to blood was higher in patients with a pseudotumour.

Conclusions: The implant orientation alone does not explain the metal concentrations found in tissues or distribution of metals between different tissues. The accumulation of metals in periprosthetic soft tissues increase the total metal load, and in the presence of a pseudotumour this is reflected in the transfer ratio of Co from synovial fluid to the blood. The total metal load of the pseudotumour tissue should be defined in future studies to determine if this will provide new insights for clinical practice.

see all

Series: BMC musculoskeletal disorders
ISSN: 1471-2474
ISSN-E: 1471-2474
ISSN-L: 1471-2474
Volume: 21
Issue: 1
Article number: 610
DOI: 10.1186/s12891-020-03636-0
Type of Publication: A1 Journal article – refereed
Field of Science: 3121 General medicine, internal medicine and other clinical medicine
Funding: This study was funded by a research grant from the Northern Finland Healthcare Support Foundation (TERTTU) and Finnish government special state support for research (VTR) (S Palosaari, TN and PL). Metal analyses in Kuopio were funded by ERDF projects A72184 and A72185 (2016–2018) Regional Council of Pohjois-Savo “Development of ICP-MS and IC systems for advanced elemental and ion analyses” (S Peräniemi and AT).
Copyright information: © The Author(s). 2020. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated in a credit line to the data.