Commentary on “Midterm clinical and radiographic results of mobile bearing revision total knee arthroplasty”

Revision knee replacement is a challenging procedure that will become more commonplace, as the number of failed total knee arthroplasty (TKA) cases predictably accompany the expected growth of primary TKAs. Implant choice is only one of many variables surgeons must decide on when performing revision TKA (1). The trial conducted by Raymond Kim and colleagues on Midterm Clinical and radiographic results of mobile-bearing revision TKA was very well written, with average 5-year and minimum 2-year follow up. A proposed advantage of mobile bearing revision TKA is possible decreased implant fixation stresses, leading to decreased rates of aseptic loosening when compared to fixed bearing devices (2). Secondly, mobile bearing devices may decrease polyethylene wear and the authors propose that this is particularly important in constrained revision implants. Level of constraint in revision TKA is debatable, with good to excellent results in the literature for both fixed bearing and constrained implants (3-7). The results presented in this paper on mobile bearing revision TKA are quite comparable to those of contemporary revision TKA with fixed bearings. These results offer no clear advantage at the present time compared to fixed bearing designs. This paper should be commended as being the first published series on mobile bearing revision TKA. While the proposed advantages of such implants was not demonstrated in this series, perhaps longer follow up and a comparator group including fixed bearing implants may help further elucidate these issues. Presently, the increased cost of these implants cannot be justified.

Acknowledgments

Funding: None.

Footnote

Provenance and Peer Review: This article was commissioned and reviewed by the Executive Editor-in-Chief, Dongquan Shi, MD, PhD (Department of Sports Medicine and Adult Reconstruction, Drum Tower Hospital, Medical School, Nanjing University, Nanjing, China).

Conflicts of Interest: Both authors have completed the ICMJE uniform disclosure form (available at http://dx.doi.org/10.21037/aoj.2017.05.04). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

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