Local bisphosphonate release versus hydroxyapatite coating for stainless steel screw fixation in rat tibiae
2012 (English)In: Journal of materials science. Materials in medicine, ISSN 0957-4530, E-ISSN 1573-4838, Vol. 23, no 3, 743-752 p.Article in journal (Refereed) Published
Implant fixation in bone can be improved by a coating that delivers bisphosphonates locally, or by a hydroxyapatite (HA) coating. In this study, we compared these different types of coatings. For mechanical testing, 30 rats were assigned into three groups, and similar screws were implanted bilaterally in the proximal tibiae. The rats received screws that were either uncoated, coated with nano-crystalline hydroxyapatite or coated with a bisphosphonate releasing protein matrix. After 4 weeks, one screw was subjected to pull-out testing, and the contra-lateral one to torsion testing. For morphology, 30 rats were assigned to similar treatment groups, but received only one screw each. Bisphosphonates enhanced the pull-out force by 41% (P = 0.02) compared to controls, HA increased the pull-out force although not significantly. Conversely, HA increased the maximal torque by 64% (P = 0.02). Morphometry showed higher bone volume around bisphosphonate screws in comparison to HA-coated screws (P andlt; 0.001) and controls (P andlt; 0.001). The results suggest that bisphosphonates improve fixation by increasing the amount of surrounding bone, whereas HA mainly improves bone to implant attachment.
Place, publisher, year, edition, pages
Springer Verlag (Germany) , 2012. Vol. 23, no 3, 743-752 p.
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:liu:diva-76616DOI: 10.1007/s10856-011-4539-5ISI: 000301639900014OAI: oai:DiVA.org:liu-76616DiVA: diva2:515449
Funding Agencies|Swedish Research council|2009-6725|BIOMATCELL VINN Excellence Center of Biomaterials and Cell Therapy at Sahlgrenska Academy, University of Gothenburg||2012-04-132012-04-132012-04-13