title: Comparing PMMA and calcium sulfate as carriers for the local delivery of antibiotics to infected surgical sites.
abstract: Antibiotic-loaded bone cement is a primary option for treatment of orthopedic infections. Poly(methyl methacrylate) (PMMA) is a widely used cement that, when loaded with antibiotics in spacer or bead form, has been shown to reduce infection rates. However, PMMA is not resorbable and requires a second surgery for removal, while also acting as a potential foreign body for bacterial colonization. Alternatively, resorbable bone cements, such as calcium sulfate, have been proposed and present the advantage of being completely reabsorbed. It is unknown whether the antibiotic elution characteristics of absorbable bone cements are similar to PMMA. This study (1) characterized antibiotic elution from synthetic, highly purified calcium sulfate cement beads of varying sizes against pathogenic bacteria both in liquid culture and seeded on agar plates, (2) tested calcium sulfate beads against PMMA beads loaded with the same antibiotics, and (3) analyzed the structural differences between how PMMA and calcium sulfate bind to antibiotics. In every assay, the calcium sulfate beads performed as well as, or better than, the PMMA beads in inhibition of bacterial growth and elution of vancomycin in vitro with complete elution observed from calcium sulfate within three days. These data suggest that calcium sulfate, functions, as well as PMMA in the patient setting for infection control.
authors.affiliation: Department of Orthopaedics, The Ohio State University Columbus, Ohio.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: McConoughey
authors.forename: Robert P
authors.initials: RP
authors.lastname: Howlin
authors.forename: Jessica
authors.initials: J
authors.lastname: Wiseman
authors.forename: Paul
authors.initials: P
authors.lastname: Stoodley
authors.forename: Jason H
authors.initials: JH
authors.lastname: Calhoun
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology; D018786:Bone Substitutes / Q000737:chemistry / Q000494:pharmacology; D002133:Calcium Sulfate / Q000737:chemistry / Q000494:pharmacology; D004337:Drug Carriers; D055624:Methicillin-Resistant Staphylococcus aureus / Q000254:growth & development*; D019904:Polymethyl Methacrylate / Q000737:chemistry / Q000494:pharmacology; D013212:Staphylococcus epidermidis / Q000254:growth & development*; D013530:Surgical Wound Infection / Q000188:drug therapy*
chemical_list: D000900:Anti-Bacterial Agents; D018786:Bone Substitutes; D004337:Drug Carriers; D019904:Polymethyl Methacrylate; D002133:Calcium Sulfate
keywords: PMMA; bacteria; bioabsorption; calcium sulfate; infection