An in vitro experimental study on the physical and elution properties of PMMA bone cement loaded with rifampicin, iso-niazid, pyrazinamide and moxifloxacin / 中华骨科杂志

ABSTRACT

Objective To investigate the feasibility of Antituberculotic?loaded bone cement (ATLBC) prepared by mix?ing the anti?TB drugs Rifampicin (RFP), Isoniazid (INH), Pyrazinamid (PZA), Moxifloxacin (MFX) with Palacos R PMMA bone cement in Total Joint Arthroplasty treatment for Joint Tuberculosis. Methods Forty grams of Palacos R bone cement powder without antibiotics was mixed with 1 or 2 grams of RFP, INH, PZA and MFX respectively. According to ISO 58332002 stan?dard, 8 groups of ATLBC standard test specimen were prepared as experiment group and Palacos R PMMA bone cement with?out antibiotics was prepared as control group. Physical properties (such as the average dough time, curing time, maximum tem?perature), mechanical strength (such as the compressive strength, the bending resistance strength, the modulus of elasticity) and the concentrations of eluant drug in different time points of ATLBC were detected. Results In RFP (1 g), RFP (2 g), INH (1 g) and INH (2 g) group, the average dough time and curing time were longer than those in control group, which exceeded the standard scope of ISO, while the average maximum temperature was significantly lower than that in control group. The INH ( 1 g) group and INH (2 g) group hardened after mixing for 14 days. The RFP (1 g) group and RFP (2 g) group hardened after mixing for 30 days. Twenty minutes after mixing and hardening, the compressive strength, bending resistance strength and modulus of elastic?ity were significantly lower than the specified values of ISO standard. The physical properties and mechanical strength in PZA ( 1 g) group, PZA (2 g) group, MFX (1 g) group, MFX (2 g) group and control group were in accordance with the specified values of ISO standard, and they hardened after 20 minutes. In RFP (1 g) group, RFP (2 g) group, INH (1 g) group, INH (2 g) group, PZA (1 g) group, PZA (2 g) group, MFX (1 g) group and MFX (2 g) group, the concentration of eluant could maintain for 3 days, 7 days, 90 days, 90 days, 45 days, 60 days, 60 days and 60 days respectively. Conclusion RFP and INH mixing with Palacos R PMMA bone cement can hinder the aggregation of bone cement so they are unsuitable for preparing ATLBC. PZA and MFX mixing with Palacos R PMMA bone cement do not affect the physical properties of bone cement, with excellent mechanical strength and elu?tion properties. Because the minimal inhibitory concentration of PZA is higher and its antimicrobial activity maintains shorter time, while MFX maintains longer time in antimicrobial activity, it's more suitable for the preparation of ATLBC.