Colin Y L Woon1, Amanda Wach2, Timothy M Wright2, Douglas E Padgett1. 1. Adult Reconstruction and Joint Replacement, Hospital for Special Surgery, New York, NY. 2. Department of Biomechanics, Hospital for Special Surgery, New York, NY.
Abstract
BACKGROUND: We investigated the effect of taper design, head material, and manufacturer on simulated mechanically assisted crevice corrosion (MACC). METHODS: Six pristine C-taper stems coupled with alumina-zirconia or cobalt-chromium (CoCr) heads were tested in a mechanical/electrochemical setup to measure average fretting currents and fretting current onset loads. Outcomes were compared with previous data from V40 tapers from the same manufacturer and 12/14 tapers from another manufacturer. RESULTS: Within a single manufacturer, differences in average fretting current between V40 and C-taper designs were dependent on head material. Only with V40 tapers did CoCr heads show higher average fretting currents than ceramic heads. Between manufacturers, differences were found between similar taper designs, as 12/14 taper couples showed higher average fretting currents than C-taper couples, regardless of head material. CONCLUSION: Taper design, head material, and factors inherent to different manufacturers influence fretting current in simulated MACC. Unlike clinical and retrieval studies, this experimental design allows for investigations of factors affecting MACC in a controlled environment. Taper design, independent of manufacturer, contributes to the observed differences in average fretting current between head materials. In some taper designs, head composition, specifically ceramic, should not be considered alone to reduce risk of corrosion.
BACKGROUND: We investigated the effect of taper design, head material, and manufacturer on simulated mechanically assisted crevice corrosion (MACC). METHODS: Six pristine C-taper stems coupled with alumina-zirconia or cobalt-chromium (CoCr) heads were tested in a mechanical/electrochemical setup to measure average fretting currents and fretting current onset loads. Outcomes were compared with previous data from V40 tapers from the same manufacturer and 12/14 tapers from another manufacturer. RESULTS: Within a single manufacturer, differences in average fretting current between V40 and C-taper designs were dependent on head material. Only with V40 tapers did CoCr heads show higher average fretting currents than ceramic heads. Between manufacturers, differences were found between similar taper designs, as 12/14 taper couples showed higher average fretting currents than C-taper couples, regardless of head material. CONCLUSION: Taper design, head material, and factors inherent to different manufacturers influence fretting current in simulated MACC. Unlike clinical and retrieval studies, this experimental design allows for investigations of factors affecting MACC in a controlled environment. Taper design, independent of manufacturer, contributes to the observed differences in average fretting current between head materials. In some taper designs, head composition, specifically ceramic, should not be considered alone to reduce risk of corrosion.
Authors: Bartlomiej Radzik; Divya Bijukumar; Kai-Yuan Cheng; Ravindra V Badhe; Mark Barba; Mathew T Mathew Journal: Mater Sci Eng C Mater Biol Appl Date: 2021-04-26