Can a Real-Component Articulating Spacer Eradicate Infection in Revision TKA?

    Dr. Jenna Bernstein answers ICJR’s question about a study she co-authored that compared outcomes of a real component-based articulating spacer versus an all-cement articulating spacer in patients undergoing 2-stage revision total knee arthroplasty for periprosthetic joint infection.

    ICJR: What question did you and your co-authors want to answer with this study?

    Jenna A. Bernstein, MD: Periprosthetic joint infection (PJI) continues to be a devastating complication for patients following total knee arthroplasty (TKA), [1] with a rate of 2.0% to 2.4%. [2] With this study, we attempted to answer the question of whether a real component-based articulating spacer was as effective for infection eradication as an all-cement articulating spacer. Secondary endpoints included patient outcomes such as reoperation rate, functionality, length of stay, and discharge disposition.

    Articulating spacers, defined as spacers that allow for motion at the tibiofemoral joint, come in a range of constructs. [7-11] Although a number of studies have compared outcomes between static and articulating spacers, [11-13] the literature lacks comparisons of the different types of articulating spacers.

    With the use of real-component spacers increasing over time, [4] we felt it was important to investigate whether these articulating spacers are efficacious in infection eradication.

    RELATED: Comparing the Efficacy of Articulating Spacer Constructs for Knee Periprosthetic Joint Infection Eradication: All-Cement vs Real-Component Spacers

    ICJR: What did you conclude about the use of realcomponent versus all-cement articulating spacers in a 2-stage exchange for PJI, and how did you reach this conclusion?

    Dr. Bernstein: This study was a multicenter, retrospective chart review at 3 major academic institution: NYU Langone Health, Brigham & Women’s Hospital, Massachusetts General Hospital. Data for the study were manually pulled from the electronic medical record. The study cohort included 164 patients (92 in the real-component group and 72 in the all-cement group) who had received an articulating spacer at any of the institutions in the study between April 2011 and August 2020.

    We found no statistically significant difference in reinfection at any time point up to 2 years postoperatively between patients who had received a real-component articulating spacer and those who had received an all-cement articulating spacer (P=0.581).

    Patients in the real-component articulating spacer group were more likely to be discharged home after the stage 1 procedure (P=0.008) and the stage 2 procedure (P=0.003). They also had a significantly shorter length of stay after stage 1 (P=0.006) and stage 2 (P=0.003).

    There was no significant difference between the groups in the change in arc of motion following the stage 2 procedure (P=0.641).

    We concluded, based on these finding, that surgeons could use either of the articulating spacer constructs investigated, as they were equally efficacious in infection eradication.

    However, there may be some patient outcome benefit to using the real-component articulating spacer. Despite no significant difference in the demographics of the groups, patients in the real-component articulating spacer group were more likely to be discharged home and have a shorter length of stay. This implies that they may have had an easier time functioning with the spacer, but, of course, more investigation needs to be done on this aspect of the study.

    ICJR: Why are your findings significant for clinical practice?

    Dr. Bernstein: Our findings support the use of real-component articulating spacers to treat PJI, even though it means putting metal and plastic into an infected joint.

    Although this study does not necessarily indicate that real-component articulating spacers are better than all-cement articulating spacers, it does provide assurance to surgeons that they can safely choose the construct that they feel is best in their hands and that is most cost-effective in their health system.


    Bernstein JA, Baylor J, Roof MA, Antonelli B, Chen AF, Long WJ, Schwarzkopf R. There is no difference in reinfection rates but significantly higher reoperation rates associated with premolded cement spacers than primary component spacers in treatment of prosthetic joint infection of the knee with two-stage exchange (Paper 001). Presented at the 2021 Annual Meeting of the American Academy of Orthopaedic Surgeons, August 31-September 3, San Diego, California.

    Roof MA, Baylor JL, Bernstein JA, et al. Comparing the efficacy of articulating spacer constructs for knee periprosthetic joint infection eradication: all-cement vs real-component spacers. J Arthroplasty. 2021 Jul;36(7S):S320-S327. doi: 10.1016/j.arth.2021.01.039. Epub 2021 Jan 21.

    About the Expert

    Jenna A. Bernstein, MD, is an Assistant Professor of Orthopaedics and Co-Surgical Chair of the Hip Fracture Program at Yale University School of Medicine, New Haven, Connecticut.

    Disclosures: Dr. Bernstein has no disclosures relevant to this study.


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