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Fretting Corrosion and Polyethylene Damage Mechanisms in Modular Dual Mobility Total Hip Arthroplasty
Hannah Spece
Daniel MacDonald
Michael Mont
Gwo-Chin Lee
Steven Kurtz
出版
ASTM International
, 2018
URL
http://books.google.com.hk/books?id=DaB4zgEACAAJ&hl=&source=gbs_api
註釋
Dual mobility (DM) implants can be helpful in minimizing instability and improving range of motion in patients at risk for dislocation following total hip arthroplasty. However, the additional articulation raises concerns about increased polyethylene liner damage, while an added metal interface of a modular DM design (MDM) can be a source of corrosion. This retrieval study aims to characterize in vivo damage and fretting corrosion of MDM hips. Twenty-nine MDM explants with both ceramic and metal femoral heads were collected. A custom fixture and a mechanical testing frame were used to disengage the femoral heads from the polyethylene liners. The inner and outer liner surfaces were assessed using a modified Hood method to evaluate seven different damage mechanisms. Fretting corrosion damage at the metal interfaces was assessed using a modified Goldberg method. A minimal fretting corrosion score of one was assigned to 70 % of the femoral head tapers, 75 % of the cobalt-chromium acetabular liner backsides, and 80 % of the femoral stems. Corrosion tended to occur at the acetabular liner edges rather than at the pole. There were no cases of severe corrosion on any of the components. Surface damage, primarily scratching, burnishing, pitting, and embedded debris, was observed on all 29 polyethylene liners. There was no significant difference between the overall damage of the inner and outer surface for each component (p = 0.07). However, pitting and surface deformation scores were greater for the outer surface (p = 0.01, p = 0.002), while embedded debris scores were greater for the inner surface (p = 0.01). Fretting corrosion and polyethylene damage were measurable in MDM articulations at short-term follow-up. While the clinical significance is unknown, it demonstrates the need for continued investigation as longer-term MDM retrievals become available.
