Articulating polymethylmethacrylate (PMMA) spacers may have an immunomodulating effect on synovial tissue

Area of Science:

• Orthopedic Surgery
• Immunology
• Biomaterials Science

Background:

• Two-stage revision arthroplasty for prosthetic joint infection often involves polymethylmethacrylate (PMMA) spacers.
• The tissue response to PMMA debris generated by these spacers is not fully understood.
• Understanding this response is crucial for optimizing treatment strategies.

Purpose of the Study:

• To investigate the immunomodulatory effects of PMMA debris on periprosthetic tissues during two-stage revision arthroplasty.
• To characterize the inflammatory cell infiltration and expression patterns in response to PMMA particles.

Main Methods:

• Tissue samples were collected from 35 patients undergoing two-stage revision arthroplasty.
• Fourier transform infrared microscopy confirmed PMMA particle presence.
• Immunohistochemistry (CD-68, CD-20, CD-11(c), CD-3, IL-17) and histomorphometry were used to analyze cellular responses.

Main Results:

• No significant change in mean CD-68 scores was observed between stages.
• Significant differences in CD-3, CD-20, CD-11(c), and IL-17 expression were noted in perivascular and diffuse areas.
• Dendritic cell expression shifted towards a perivascular arrangement and the periphery of PMMA particles.

Conclusions:

• Synovial tissue exhibits a biological reaction to PMMA spacers, characterized by altered dendritic cell distribution and increased perivascular lymphocytes.
• The use of PMMA spacers in two-stage revision for joint infection likely induces immunomodulation of synovial tissues.
• These findings highlight the complex interplay between biomaterial debris and the host immune system in infected joint revisions.