Biaxial flexural modulus of antibiotic‐impregnated orthopedic bone cement

Abstract

Previously reported antibiotic-impregnated cement strengths have been based on uniaxial and fatigue testing methodologies. These methods may not provide an accurate characterization of bone cement's true load-bearing capacity in total joint replacement (TJR). The present study utilized biaxial testing to report on the properties of antibiotic-impregnated cement. Test groups included: PMMA mixed with Vancomycin, Gentamicin, Tobramycin, or no antibiotic (control). In comparison to the control group, PMMA samples mixed with powdered gentamicin resulted in an increase in the mean elastic modulus by 6.50% versus a drop noted with powdered vancomycin and tobramycin by 2.65 and 1.37% respectively. The mean elastic modulus in samples containing liquid gentamicin dropped by 11.6%. This study supports the continued use of powdered antibiotics when clinically indicated, but suggest caution in the use of liquid gentamicin in TJR.

Impact Resistance of Antibiotic-Impregnated Orthopedic Bone Cement

“…Pilot data confirmed that the silicone spray did not change the impact strength of the test specimens, as reported in other works [7]. The final configuration of each sample resembled a rectangular block measuring 63.5x12.7x12.7 mm.…”

“…Cement testing studies have incorporated different testing methodologies and conditions resulting in a wide range of reported findings. The cement strength studies have been based on uniaxial, biaxial and fatigue testing methodologies using tension, flexural, or compressive testing [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Among the reported properties, the impact strength of bone cement has received very little attention; with the only reports are those by Ungethulum and Hinterberger [21], Ege [22] and Lewis and Mladsi [23].…”

“…Many biomechanical studies have investigated the effects of adding various types of antibiotics in bone cements on its mechanical properties [3][4][5][6][7]. Cement testing studies have incorporated different testing methodologies and conditions resulting in a wide range of reported findings.…”

Surfactant-stabilized Emulsion Increases Gentamicin Elution From Bone Cement

“…Other authors report data from ALBC made with liquid antimicrobial [4,5,9,14]; however, only Seldes [14] and Hseih et al [6] report release data. Seldes [14] did not describe his methods or analysis in sufficient detail to compare his data with other studies.…”

“…Young's modulus is also decreased more [9]. Antibacterials are generally soluble in water but not in methyl methacrylate (MMA) monomer.…”