Microchemical and surface evaluation of canine tibial plateau leveling osteotomy plates.
OBJECTIVE
To determine the microchemical and surface composition of tibial plateau leveling osteotomy (TPLO) plates before and after explantation.


METHODS
7 TPLO plates surgically removed from host dogs 6 to 54 months after implantation; 2 raw unpolished-and-unpassivated 316L TPLO plates; and 2 heat-treated, polished-and-passivated, and cleaned 316L TPLO plates.


METHODS
Samples were removed by use of standard techniques to ensure the plate surface was not damaged. Sample pieces were dissolved and analyzed by inductively coupled plasma-mass spectrometry (ICP-MS) to determine bulk elemental composition. Other sample pieces were investigated by use of scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and x-ray photoelectron spectroscopy (XPS) for determination of sample morphology, near-surface elemental composition, and surface elemental composition, respectively. To investigate the possibility of corrosion in situ, some samples were chemically corroded and analyzed.


RESULTS
ICP-MS confirmed that elemental composition of samples was consistent with 316L stainless steel. The SEM and EDS analyses revealed trace amounts of polishing materials and a nonuniform carbonaceous biofilm on < 1% of the surface area of samples removed from the host dogs. The XPS analysis indicated an increase in the chromium-to-iron ratio on passivated surfaces, with no difference between passivated samples before implantation and after explantation.


CONCLUSIONS
Composition of the TPLO plates was consistent with 316L stainless steel. No chemical or topographic changes were detected in TPLO plates that had been implanted in dogs for up to 54 months. A small amount of biofilm was evident on the surface of 2 plates.
Department of Chemistry, College of Science, Texas A&M University, College Station, TX 77842, USA.
William M
WM
Lackowski
Yulia B
YB
Vasilyeva
Richard M
RM
Crooks
Sharon C
SC
Kerwin
Donald A
DA
Hulse
D000818:Animals; D001672:Biocompatible Materials / Q000009:adverse effects; D001860:Bone Plates / Q000662:veterinary*; D004283:Dog Diseases / Q000601:surgery*; D004285:Dogs; D006614:Hindlimb; D010027:Osteotomy / Q000295:instrumentation / Q000662:veterinary*
D001672:Biocompatible Materials