Publication details

Authors: Kraus, Tanja; Moszner, Frank; Fischerauer, Stefan; Fiedler, Michael; Martinelli, Elisabeth; Eichler, Johannes; Witte, Frank; Willbold, Elmar; Schinhammer, Michael; Meischel, Martin; Uggowitzer, Peter J.; Löffler, Jörg F.; Weinberg, Annelie 
Title: Biodegradable Fe-based alloys for use in osteosynthesis: Outcome of an in vivo study after 52 weeks 
Type: Journal Article 
Publisher: Acta Biomaterialia 
Year: 2014 
Volume: 10 
Start Page: 3346 
End Page: 3353 
DOI: 10.1016/j.actbio.2014.04.007 
Abstract: This study investigates the degradation performance of three Fe-based materials in a growing rat skeleton over a period of 1 year. Pins of pure Fe and two Fe-based alloys (Fe10Mn1Pd and Fe21Mn0.7C1Pd, in wt.%) were implanted transcortically into the femur of 38 SpragueDawley rats and inspected after 4, 12, 24 and 52 weeks. The assessment was performed by ex vivo microfocus computed tomography, weight-loss determination, surface analysis of the explanted pins and histological examination. The materials investigated showed signs of degradation; however, the degradation proceeded rather slowly and no significant differences between the materials were detected. We discuss these unexpected findings on the basis of fundamental considerations regarding iron corrosion. Dense layers of degradation products were formed on the implants surfaces, and act as barriers against oxygen transport. For the degradation of iron, however, the presence of oxygen is an indispensable prerequisite. Its availability is generally a critical factor in bony tissue and rather limited there, i.e. in the vicinity of our implants. Because of the relatively slow degradation of both pure Fe and the Fe-based alloys, their suitability for bulk temporary implants such as those in osteosynthesis applications appears questionable. 
Keywords: Iron, Iron alloys, Biodegradation, Fracture fixation, ¼CT