ABSTRACT
Metallosis is a term used to describe staining of tissues exposed to metal particles and ions in-
vivo. There is no explicit diagnosis for metallosis, but it is recognized as a significant health
threat per the FDA as the released metals are associated with cardiotoxicity, neurotoxicity, and
cancers. The overarching hypothesis of this work is that in-vivo non-pathogenic bacterial
biofilms on spinal hardware affect the release of metal via corrosion thus causing metallosis in
patients. To test this hypothesis, we will pursue the following aims: Specific Aim 1 will examine
the association of bacteria with observed corrosion on the surfaces of spine hardware via the
quantification of surface damage and the presence of bacterial associated biomolecules
integrated into the damaged surfaces. To do so we will use surface optical microscopy to
quantify the type and area coverage of surface modification whether wear or corrosion, over the
entire device component, pedicel screw or rod. Optical microscopy determination of corrosion
regions without existing mechanical damage will elucidate the total possible amount of metal
release based on surface area measurements. How these surfaces are modified beyond
mechanical damage will be characterized using Time of Flight-Scanning Ion Mass Spectroscopy
(TOF-SIMS) and X-ray Photoelectron Spectroscopy (XPS). Work in Specific Aim 2 will
characterize the bacterial milieu constituting the biofilms on explanted spine hardware in
metallosis cases. Because of the lack of understanding of the in-vivo spinal instrumentation
microbiome, this Aim will identify the common microbes associated with implant corrosion. The
impact of this work will be to give insight to the mechanisms of in-vivo metal corrosion, thus
leading to possible changes in clinical treatments, the necessity of new or modified materials, or
changes to surgical procedures to reduce the risk of metallosis.