Balancing strength and sterility: An in vitro assessment of the mechanical and antibacterial properties of bone cement loaded with various antibiotics
Tarik Elma1
, Hakan Yusuf Selek2, Mehmet Ali Tokgoz2, Ali Ekber Yapar3, Tugba Cuhadar4
1Department of Orthopedics and Traumatology, Private Medline Adana Hospital, Adana, Türkiye
2Department of Orthopedics and Traumatology, Gazi University Faculty of Medicine, Ankara, Türkiye
3Department of Orthopedics and Traumatology, Antalya Training and Research Hospital, Antalya, Türkiye
4Department of Medical Microbiology, Gazi University Faculty of Medicine, Ankara, Türkiye
Keywords: Bone cements with antibiotics, infected bone, mechanical strength.
Abstract
Objectives: This study aims to determine the antimicrobial efficacy and mechanical strength of antibiotic-loaded cement samples in which daptomycin, vancomycin, teicoplanin, meropenem and piperacillin-tazobactam agents were mixed at different doses and to investigate the differences between agents and between doses.
Materials and methods: We prepared standardized bone cement samples incorporating vancomycin, teicoplanin, daptomycin, piperacillin-tazobactam, and meropenem at concentrations ranging from 0.625 to 15%. Samples underwent six-week phosphate-buffered saline immersion simulating physiological conditions. Mechanical testing employed four-point bending analysis following ISO 5833 standards. Antimicrobial efficacy was assessed using liquid microdilution against Staphylococcus aureus and Pseudomonas aeruginosa over 21 days.
Results: All antibiotics demonstrated strong negative correlation between concentration and mechanical strength (r=–0.883 to –0.914, p<0.001). Critical threshold emerged at 5% antibiotic concentration, above which mechanical integrity was significantly compromised. Daptomycin and meropenem maintained superior mechanical properties at effective antimicrobial concentrations. At 2-g doses, daptomycin achieved significantly higher strength than piperacillin-tazobactam and teicoplanin (p=0.021). All antibiotics except low-dose piperacillin-tazobactam maintained complete antimicrobial efficacy throughout 21-day testing. Electron microscopy revealed increased porosity, which correlated with reduced mechanical strength, particularly in piperacillin-tazobactam and teicoplanin groups.
Conclusion: Antibiotic selection significantly impacts both mechanical and antimicrobial properties of bone cement. Daptomycin and meropenem offer optimal balance of antimicrobial efficacy and mechanical integrity. These findings provide evidence-based guidelines for antibiotic selection in resistant infection management while maintaining structural requirements.
Citation: Elma T, Selek HY, Tokgoz MA, Yapar AE, Cuhadar T. Balancing strength and sterility: An in vitro assessment of the mechanical and antibacterial properties of bone cement loaded with various antibiotics. Jt Dis Relat Surg 2026;37(1):238-247. doi: 10.52312/jdrs.2026.2507.