Development and Evaluation of a Reusable Sterilizable Silicone Mold System Combined with Dual Antibiotic-Loaded PMMA Cement for Dynamic Articulating Spacer Fabrication

Background: Periprosthetic joint infection (PJI) is a serious complication of total joint arthroplasty commonly managed by two-stage revision using antibiotic-loaded articulating spacers. Objective: This study evaluated a dual-antibiotic-loaded PMMA bone cement developed for the fabrication of dynamic spacers.Methods: In this in vitro experimental study, ۴ g of vancomycin hydrochloride was incorporated into a commercially available gentamicin-loaded PMMA bone cement (CEMEX® GENTA). A reusable silicone mold was developed to fabricate anatomically accurate femoral spacer components. The developed cement was compared with the standard formulation regarding macroscopic appearance, color characteristics, polymerization behavior, setting time, maximum polymerization temperature, compressive strength, tensile strength, electrical resistance, and molding performance according to ISO ۵۸۳۳. Statistical analysis was performed using the independent-samples t-test (p < ۰.۰۵).Results: The addition of vancomycin slightly increased cement opacity without affecting surface morphology or dimensional accuracy. The developed cement exhibited a significantly shorter setting time (p = ۰.۰۳), whereas no significant differences were observed in doughing time, maximum polymerization temperature, compressive strength, tensile strength, electrical resistance, or molding performance (p > ۰.۰۵). Both formulations demonstrated excellent moldability and produced anatomically accurate femoral spacer components.Conclusions: The developed dual-antibiotic-loaded PMMA bone cement preserved the essential physicochemical, mechanical, and molding properties of the original cement while enabling the fabrication of dynamic articulating spacers using a reusable silicone mold. This approach represents a promising strategy for the fabrication of temporary spacers in the management of periprosthetic joint infection.

Keywords:

Polymethyl methacrylate (PMMA) , Antibiotic-loaded bone cement , Gentamicin , Vancomycin , Dynamic articulating spacer , Periprosthetic joint infection