title: In vivo evaluation of bioactive PMMA-based bone cement with unchanged mechanical properties in a load-bearing model on rabbits.
abstract: Polymethylmethacrylate-based bone cements are widely used for fixation of joint replacements. To improve the long-term outcome, bioactive bone cements are aspired to advance the bone-cement interface. This study evaluated the in vivo properties of a new polymethylmethacrylate-based bioactive bone cement with addition of amphiphilic phosphorylated 2-hydroxyethylmethacrylate. Previous in vitro studies confirmed bioactive properties in cell culture, as well as unchanged mechanical properties are tests according to ISO 5833:2002.Three different variations of the cement (polymethylmethacrylate + phosphorylated 2-hydroxyethylmethacrylate, polymethylmethacrylate + phosphorylated 2-hydroxyethylmethacrylate + CaCl2 and polymethylmethacrylate + phosphorylated 2-hydroxyethylmethacrylate + CaCl2 + Na2CO3) were compared to conventional polymethylmethacrylate cement. To evaluate the properties under load-bearing conditions, a spacer prosthesis was implanted into the femoral diaphysis of 24 rabbits. Additionally, a cement plug was installed into the proximal tibia. After three months, polished sections with Giemsa surface staining were prepared. The bioactivity was determined using the bone affinity index.The sections showed a good osseointegration of the bioactive bone cement without cement cracks under load-bearing conditions. Regarding the bone affinity index, the bioactive bone cement revealed a significantly higher value in the proximal tibia (25.9-37.7%) and around the spacer prosthesis (36.8-58.9%) compared to the conventional polymethylmethacrylate cement (12.8-17.0%).The results confirm the in vivo bioactivity of this bone cement. The absence of cement cracks indicates a sufficient mechanical stability to fix prostheses with this bioactive cement, but for a final assessment long-term tests are necessary.
authors: Department of Orthopaedic Surgery, Physical Medicine and Rehabilitation, University Hospital of Munich (LMU), Campus Großhadern, Munich, Germany andreas.fottner@med.uni-muenchen.de.
authors: Andreas
authors: A
authors: Fottner
authors: InnoTERE GmbH, Pharmapark Radebeul, Radebeul, Germany.
authors: Berthold
authors: B
authors: Nies
authors: Department of Orthopaedic Surgery, Physical Medicine and Rehabilitation, University Hospital of Munich (LMU), Campus Großhadern, Munich, Germany.
authors: Denis
authors: D
authors: Kitanovic
authors: Department of Orthopaedic Surgery, Physical Medicine and Rehabilitation, University Hospital of Munich (LMU), Campus Großhadern, Munich, Germany.
authors: Arnd
authors: A
authors: Steinbrück
authors: Department of Orthopaedic Surgery, Physical Medicine and Rehabilitation, University Hospital of Munich (LMU), Campus Großhadern, Munich, Germany.
authors: Jörg
authors: J
authors: Hausdorf
authors: Department of Orthopaedic Surgery, Physical Medicine and Rehabilitation, University Hospital of Munich (LMU), Campus Großhadern, Munich, Germany.
authors: Susanne
authors: S
authors: Mayer-Wagner
authors: Walter Brendel Centre of Experimental Medicine, Munich, Germany.
authors: Ulrich
authors: U
authors: Pohl
authors: Department of Orthopaedic Surgery, Physical Medicine and Rehabilitation, University Hospital of Munich (LMU), Campus Großhadern, Munich, Germany.
authors: Volkmar
authors: V
authors: Jansson
mesh_terms: D000818:Animals; D001843:Bone Cements / Q000737:chemistry*; D005269:Femur / Q000033:anatomy & histology / Q000502:physiology / Q000601:surgery; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry*; D016348:Osseointegration; D010766:Phosphorylation; D019904:Polymethyl Methacrylate / Q000737:chemistry*; D019736:Prostheses and Implants; D011817:Rabbits; D013314:Stress, Mechanical; D013977:Tibia / Q000033:anatomy & histology / Q000502:physiology / Q000601:surgery; D016474:Weight-Bearing
chemical_list: D001843:Bone Cements; D008689:Methacrylates; C005044:hydroxyethyl methacrylate; D019904:Polymethyl Methacrylate
keywords: Bioactive bone cement; bone affinity index; in vivo properties; load bearing; polymethylmethacrylate