Polyethylene Dual Mobility Liners Show Minimal Polyethylene Changes in Early Retrievals.

Autor: Zlotnicki JP; Hospital for Special Surgery, Adult Reconstruction and Joint Replacement, New York, New York., Baral EC; Hospital for Special Surgery, Department of Biomechanics, New York, New York., Westrich GH; Hospital for Special Surgery, Adult Reconstruction and Joint Replacement, New York, New York., Wright TM; Hospital for Special Surgery, Department of Biomechanics, New York, New York.
Jazyk: angličtina
Zdroj: The Journal of arthroplasty [J Arthroplasty] 2023 Jun; Vol. 38 (6), pp. 1172-1176. Date of Electronic Publication: 2023 Mar 05.
DOI: 10.1016/j.arth.2023.02.068
Abstrakt: Background: Dual mobility (DM) liners were introduced to reduce instability in total hip arthroplasty. They were found to allow for motion predominantly at the femoral head and the inner bearing of the acetabular liner; however, little is known if this motion is sufficient to alter polyethylene material characteristics. We assessed cross-link (XL) density and oxidation index (OI) measurements of the inner and outer bearing articulations.
Methods: Thirty-seven DM liners were collected with a duration of implantation greater than 2 years. Clinical and demographic data were collected from a chart review. A cylinder was cored from the apex of each liner and cut into 4.5 mm long inner and outer diameter segments for XL density swell ratio testing. The OI was measured from sagittal 100 μm microtome slices using Fourier transform infrared spectroscopy. Student's t-tests were used to determine differences in OI and XL density between the bearings. Spearman's correlation assessed relationships between patient demographics, OI, and XL density. Duration of implantation for the cohort was a mean of 35 (range, 24-96) months.
Results: The inner and outer bearing had similar median XL densities (0.17 mol/dm 3 versus 0.17 mol/dm 3 , P = .6). The inner bearing had an increased OI when compared to the outer bearing (0.16 versus 0.13, P = .008). The OI was inversely correlated with XL density (r = -0.50, P = .002).
Conclusion: Small differences were found in oxidation between the inner and outer bearing of the DM construct. Failures at an average of 3 years indicate low levels of oxidation, unlikely to impact the mechanical properties of the material.
(Copyright © 2023 Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
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