Design, Material, and Seating Load Effects on In Vitro Fretting Corrosion Performance of Modular Head-Neck Tapers.

Background: The short-term corrosion and micromechanical behavior of 32 unique head-neck taper design/material/assembly conditions was tested using an incremental cyclic fretting corrosion (ICFC) test method previously developed.

Methods: Seven materials, design, and simulated surgical parameters were evaluated, each being assigned 2 conditions for testing, using a 2 (7 factor, quarter factorial) design of experiments test matrix. The factors explored were (1) seating load, (2) head-neck offset, (3) material combination, (4) taper diameter, (5) taper roughness, (6) angular mismatch/engagement, and (7) taper length.

Material dependent fretting corrosion in spinal fusion devices: Evaluation of onset and long-term response.

Posterior spinal fusion implants include number of interconnecting components, which are subjected to micromotion under physiological loading conditions inducing a potential for fretting corrosion. There is very little known about the fretting corrosion in these devices in terms of the minimum angular displacement (threshold) necessary to induce fretting corrosion or the amount of fretting corrosion that can arise during the life of the implant. Therefore, the first goal was to evaluate the threshold fretting corrosion in three anatomical orientations and second the long-term fretting corrosion for the three different material types of spinal implants under physiological loading conditions.

Effect of mixed alloy combinations on fretting corrosion performance of spinal screw and rod implants.

Spinal implants are made from a variety of materials to meet the unique mechanical demands of each application. However, the medical device community has raised concern about mixing dissimilar metals in an implant because of fear of inducing corrosion. There is a lack of systematic studies on the effects of mixing metals on performance of spinal implants, especially in fretting corrosion conditions.

Incorporation of Ca and P on anodized titanium surface: Effect of high current density.

This study systematically evaluated the surface and corrosion characteristics of commercially pure titanium (grade 2) modified by plasma electrolytic oxidation (PEO) with high current density. The anodization process was carried out galvanostatically (constant current density) using a solution containing calcium glycerophosphate (0.02mol/L) and calcium acetate (0.