Long-term evaluation of a calcium phosphate bone cement with carboxymethyl cellulose in a vertebral defect model
Journal of Biomedical Materials Research Part A, 2009
We investigated histological and compressive properties of a calcium phosphate bone cement (BoneS... more We investigated histological and compressive properties of a calcium phosphate bone cement (BoneSource (CPC); Stryker Orthopaedics, Mahwah, New Jersey) plus carboxymethyl cellulose (CMC) using a sheep vertebral bone void model. Bone voids were surgically created in L3 and L5 in each of 40 sheep, and the voids were filled with the cement. Histological and radiographic evaluations were performed on one vertebral body from each animal at either: 0, 3, 6, 12, 24, or 36 months after surgery; mechanical testing was performed on operated and non-operated vertebral bodies from 35 sheep. Undecalcified sections were digitized, and the area of the original defect, new bone formation, empty space, fibrous tissue, and residual cement were quantified with histomorphometry. Decalcified sections were evaluated qualitatively. The cement was biocompatible, extremely osteoconductive and underwent steady resorption and replacement by bone and bone marrow. Histomorphometry showed variations in the rate of cement remodeling among animals in each time group, but on average, at 36 months the original defect area was occupied by approximately 14% bone, 82% cement, and 4% bone marrow. Even in animals that had greater resorption of cement, there was good bone ingrowth with no fibrous tissue. Compressive testing did not reveal a significant difference in the mechanical properties between vertebral bodies augmented with cement and non-augmented controls, irrespective of the postoperative time. BoneSource mixed with CMC had adequate osteoconductivity, biocompatibility, and adequate compressive strength. There was variability among animals, but histology suggests that considerable cement was still present in most samples after 36 months.
Uploads
Papers by Thomas Bauer
Taking that as a starting point of arguing a rough design on media humanism - meant by purpose as an anthropo-logical stimulus to rethink the theoretical concepts of media in and because of their relation to the human conditions of social life (humankind existence) as well as to the notion of dignity of human, humanity and humanness, humanity and humanness.
The pleadings for humanity (humanness) in context of the analysis of societal media event (eventness) and of the inherent chances and challenges for the postulates of values is not morally meant but ethical-logically. The assertive term of humanity is about a determination of a referential measurement (value), which is experienced in context of everyday life, it is about an hermeneutical concept (measurement, interpretation, resolution, calculation) to value the possibilities of enactment of that life-typical permanent conditions of ambivalence. That is only possible within the logical structure of philosophical- phenomenological and hermeneutical approach.