Journal of Materials Science: Materials in Medicine

, Volume 23, Issue 3, pp 743–752

Local bisphosphonate release versus hydroxyapatite coating for stainless steel screw fixation in rat tibiae

  • F. Agholme
  • T. Andersson
  • P. Tengvall
  • P. Aspenberg
Article

DOI: 10.1007/s10856-011-4539-5

Cite this article as:
Agholme, F., Andersson, T., Tengvall, P. et al. J Mater Sci: Mater Med (2012) 23: 743. doi:10.1007/s10856-011-4539-5

Abstract

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 < 0.001) and controls (P < 0.001). The results suggest that bisphosphonates improve fixation by increasing the amount of surrounding bone, whereas HA mainly improves bone to implant attachment.

Copyright information

© Springer Science+Business Media, LLC 2011

Authors and Affiliations

  • F. Agholme
    • 1
  • T. Andersson
    • 1
  • P. Tengvall
    • 2
  • P. Aspenberg
    • 1
  1. 1.Orthopedics, Department of Clinical and Experimental Medicine, Faculty of MedicineLinköping UniversityLinköpingSweden
  2. 2.Department of Biomaterials, Institute for Clinical Sciences, Sahlgrenska AcademyUniversity of GothenburgGothenburgSweden