gms | German Medical Science

Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2017)

24.10. - 27.10.2017, Berlin

In vitro data suggest reversibility of MoM wear induced decrease in osteogenic capacity of mesenchymal stromal cells

Meeting Abstract

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  • presenting/speaker Anastasia Rakow - Charité - Universitätsmedizin Berlin, Centrum für Muskuloskeletale Chirurgie, Berlin, Germany
  • Georg Duda - Charité - Universitätsmedizin Berlin, Julius Wolff Institut, Berlin-Brandenburger Centrum für Regenerative Therapien, Berlin, Germany
  • Carsten Perka - Charité - Universitätsmedizin Berlin, Centrum für Muskuloskeletale Chirurgie, Berlin, Germany
  • Janosch Schoon - Charité - Universitätsmedizin Berlin, Julius Wolff Institut, Berlin-Brandenburger Centrum für Regenerative Therapien, Berlin, Germany

Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2017). Berlin, 24.-27.10.2017. Düsseldorf: German Medical Science GMS Publishing House; 2017. DocIN25-806

doi: 10.3205/17dkou046, urn:nbn:de:0183-17dkou0464

Veröffentlicht: 23. Oktober 2017

© 2017 Rakow et al.
Dieser Artikel ist ein Open-Access-Artikel und steht unter den Lizenzbedingungen der Creative Commons Attribution 4.0 License (Namensnennung). Lizenz-Angaben siehe http://creativecommons.org/licenses/by/4.0/.


Gliederung

Text

Objectives: Metal-on-metal (MoM) couplings have raised severe safety concerns for several years. Recently, it was reported that bone marrow chromium (Cr) and cobalt (Co) concentrations were elevated as a result of MoM wear. Consequently, bone marrow residing mesenchymal stromal cells (MSCs) were impaired in their osteogenic capacity after exposure to MoM wear products, thus promoting periprosthetic osteolysis and aseptic loosening. We were able to confirm these findings by treating MSCs of non-exposed patients with Cr(III) and Co(II) in vitro. We found a substantial decrease in MSCs' cellular alkaline phosphatase (ALP) activity following Co(II) exposure. We hypothesized that this decline of cellular ALP activity could potentially be reversible if further exposure to MoM wear products was thoroughly avoided.

Methods: The study was approved by the local ethical committee; all donors gave written informed consent. MSCs were isolated from bone marrow of patients undergoing primary THA. In brief, 4.8 x 103 cells from passage two were seeded on 24-well tissue culture plates and exposed to 10 mg/L Cr(III), Co(II) or Cr(III) plus Co(II) respectively. In vitro exposure was sustained by media change at day four of cell culture. At day seven the cells were split and exposure was suspended in the course of the following cell culture passages. Cellular ALP activity was determined at day seven of every passage, normalized to cell number and referred to the corresponding untreated control.

Results: The exposure to clinically relevant amounts of Cr(III) did not lead to decreased MSCs' ALP activity during the exposure period and after suspending Cr(III) exposure (Fig.1). In contrast, after exposure to clinically relevant amounts of Co(II) and after combined Co(II) and Cr(III) exposure, we found ALP activity to be significantly diminished. This decline of ALP activity was already observed after an exposure duration of 24 hours and was found to be persistent over a period of 28 days after initial exposure (Fig.1). Beyond 35 days after initial exposure we did no longer observe a significant decrease of the MSCs' ALP activity.

Conclusion: The precursors of bone forming osteoblasts, the MSCs, are decreased in their ALP activity by exposure to Co(II) in clinically relevant concentrations. This effect might contribute to the pathomechanism of periprosthetic osteolysis, which ranks among the most common causes of failure of MoM hip endoprostheses and of subsequent revision arthroplasty.Our in vitro data indicate that the impairment of the ALP's activity is reversible if further exposure to MoM wear products is avoided thoroughly. Thus, a careful debridement eliminating all potential depots of MoM wear may potentially enhance bone quality and consequently improve outcome of revision surgery following MoM implant failure.