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Raman and Photoemission Spectroscopic Analyses of Explanted Biolox^® Delta Femoral Heads Showing Metal Transfer.

ABSTRACT: Biolox^® delta has been widely used in joint replacements thanks to its high strength and wear resistance. In this study, eleven Biolox^® delta femoral head retrievals affected by metal transfer (MT) were analysed by Raman spectroscopy to estimate the tetragonal to monoclinic zirconia phase transformation, whose occurrence may compromise ceramic chemical stability and mechanical strength. The residual stress state was evaluated by both Raman and photoemission spectroscopy. V_m monoclinic zirconia contents were higher near the centre of the articulating surface and in the MT area than in the border control area of the retrievals. In only one retrieval, stress related to MT appeared a more severe condition, able to induce zirconia phase transformation; for all the others, stresses related to loading in the central region and related to MT, were conducive to a zirconia phase transformation of nearly the same extent. V_m depth profiling analyses showed that the transformation involved different thicknesses in different samples. Raman data allowed for the investigation of the mechanism of zirconia phase transformation and confirmed that the growth stage was absent and the nucleation stage was not occurring as freely as it would in unconstrained zirconia.

SUBMITTER: Taddei P

PROVIDER: S-EPMC5551787 | biostudies-literature | 2017 Jul

REPOSITORIES: biostudies-literature

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Raman and Photoemission Spectroscopic Analyses of Explanted Biolox® Delta Femoral Heads Showing Metal Transfer.

Taddei Paola P Pavoni Eleonora E Affatato Saverio S

Materials (Basel, Switzerland) 20170703 7

Biolox® delta has been widely used in joint replacements thanks to its high strength and wear resistance. In this study, eleven Biolox® delta femoral head retrievals affected by metal transfer (MT) were analysed by Raman spectroscopy to estimate the tetragonal to monoclinic zirconia phase transformation, whose occurrence may compromise ceramic chemical stability and mechanical strength. The residual stress state was evaluated by both Raman and photoemission spectroscopy. V< ...[more]

PMID: 28773102

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Project description:ObjectiveTo introduce a novel technology currently under final development before regulatory approvals for the furtherment of cataract surgery, using the FemtoMatrix® laser system, and to demonstrate its safety and efficacy as compared to standard ultrasound phacoemulsification.MethodsThirty-three patients with bilateral cataracts were operated on with one eye undergoing PhotoEmulsification® treatment on the FemtoMatrix® device and the contralateral eye receiving the control procedure, i.e., standard ultrasound phacoemulsification treatment. The number of "zero-phaco" procedures (denoting that I/A alone was sufficient to aspirate the lens fragments and that no ultrasound energy was needed) was recorded and Effective Phaco Time (EPT) values were compared. The patient follow-up was 3 months.ResultsThirty-three eyes from a population with a mean cataract grade of 2.6 were treated on the FemtoMatrix®, of which 29 were "zero-phaco" (88%). All patients were operated on by a single surgeon who was a relative novice to the technology (63 patients treated prior to this study). Conversely, of the 33 fellow eyes who underwent standard ultrasound phacoemulsification, none were zero-phaco (0%) - all required varying degrees of ultrasound energy to make lens aspiration possible. The mean EPT was significantly lower in the PhotoEmulsification® laser group (0.2 ± 0.8 s) than in the phaco group (1.3 ± 1.2 s) (p < 0.0001). The safety profiles of the two procedures were comparable, with no device-related adverse events noted.ConclusionFemtoMatrix® is a promising femtosecond laser platform that, when compared to phacoemulsification, significantly decreases or eliminates EPT altogether. The system is used to perform PhotoEmulsification®, making zero-phaco cataract procedures feasible including in high-grade cataracts (>3). It enables personalized treatment by automatically measuring and adapting the laser energy required to obtain the most efficient cutting of the crystalline lens. This new technology appears to be safe and effective in cataract surgery.

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Dataset Information

Raman and Photoemission Spectroscopic Analyses of Explanted Biolox^® Delta Femoral Heads Showing Metal Transfer.

Publications

Raman and Photoemission Spectroscopic Analyses of Explanted Biolox<sup>®</sup> Delta Femoral Heads Showing Metal Transfer.

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