title: Analysis of metallic traces from the biodegradation of endomedullary AZ31 alloy temporary implants in rat organs after long implantation times.
abstract: AZ31 alloy has been tested as a biodegradable material in the form of endomedullary implants in female Wistar rat femurs. In order to evaluate the accumulation of potentially toxic elements from the biodegradation of the implant, magnesium (Mg), aluminium (Al), zinc (Zn), manganese (Mn) and fluorine (F) levels have been measured in different organs such as kidneys, liver, lungs, spleen and brain. Several factors that may influence accumulation have been taken into account: how long the implant has been in place, whether or not the bone is fractured, and the presence of an MgF2 protective coating on the implant. The main conclusions and the clinical relevance of the study have been that AZ31 endomedullary implants have a degradation rate of about 60% after 13 months, which is fully compatible with fracture consolidation. Neither bone fracture nor an MgF2 coating seems to influence the accumulation of trace elements in the studied organs. Aluminium is the only alloying element in this study that requires special attention. The increase in Al recovered from the sampled organs represents 3.95% of the amount contained in the AZ31 implant. Al accumulates in a statistically significant way in all the organs except the brain. All of this suggests that in long-term tests AZ31 may be a suitable material for osteosynthesis.
authors.affiliation: Department of Surface Engineering, Corrosion and Durability, National Centre for Metallurgical Research (CENIM), CSIC, Avda. Gregorio del Amo 8. 28040 Madrid, Spain.
authors.forename: O G
authors.initials: OG
authors.lastname: Bodelón
authors.forename: C
authors.initials: C
authors.lastname: Iglesias
authors.forename: J
authors.initials: J
authors.lastname: Garrido
authors.forename: C
authors.initials: C
authors.lastname: Clemente
authors.forename: M C
authors.initials: MC
authors.lastname: Garcia-Alonso
authors.forename: M L
authors.initials: ML
authors.lastname: Escudero
mesh_terms: D020341:Absorbable Implants; D000497:Alloys / Q000737:chemistry*; D000818:Animals; D018786:Bone Substitutes / Q000737:chemistry*; D003343:Corrosion; D004058:Diffusion; D019544:Equipment Failure Analysis; D005269:Femur / Q000737:chemistry* / Q000601:surgery; D008137:Longitudinal Studies; D008422:Materials Testing; D008670:Metals / Q000032:analysis*; D009928:Organ Specificity; D019736:Prostheses and Implants; D011474:Prosthesis Design; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000497:Alloys; D018786:Bone Substitutes; D008670:Metals; C586533:Mg-Al-Zn-Mn-Si-Cu alloy