학술논문

Validating a Simplified Method for Assessing Total Hip Arthroplasty Taper Corrosion Susceptibility with a 15-Year Retrieval Database
Document Type
stp-paper
Source
Modularity and Tapers in Total Joint Replacement Devices, Dec 2015, Vol. 2015, No. 1591, pp. 113-131.
Subject
taper corrosion
MACC
retrievals
fretting
Goldberg
femoral heads
modularity
Retrieval Taper Connection Damage Assessments
Language
English
Abstract
Modular total hip arthroplasty (THA) implants allow tailoring a device to specific needs by adjusting head size, material, and offset. Modularity has recently been shown to increase risk of implant-related complications via mechanically assisted crevice corrosion (MACC). The purpose of this study was to establish a simple methodology based on existing standards to assess THA susceptibility to MACC. The method was validated by comparison to a 15-year retrieval database. CoCrMo heads were assembled onto Ti-6Al-4V stem tapers per ASTM F2009-00. The 12/14 tapers were prewet with a 1.5 pH solution. Approximately 7 mL of solution was used to create a sealed acidic microenvironment. The constructs were oriented at 10° of adduction and loaded according to ASTM F2068-03. Upon completion of 10 Mcycles, constructs were disassociated per ASTM F2009-00 and taper surfaces were scored using the Goldberg method. Microscopy was performed to evaluate damage. Four linear taper scans along the taper length in four quadrants of each femoral head were taken with a profilometer. Profile deviations represented the depths of material loss. Validation was assessed by comparing scores, visual features, and material loss values of tested components to those of retrieved implants. All tapers tested exhibited corrosion damage on the stem and head tapers. Evidence of wear scars, fretting, metal transfer, and corrosion debris were found. Measurable material loss occurred on all femoral head tapers. Stem machine lines transferred to the heads were found. This study used ASTM standards to reproduce MACC in an accelerated protocol. Results were consistent with published findings and a 15-year retrieval database. This database revealed MACC on worst-case samples of commonly used head diameters (