Wear characteristics of an unconstrained lumbar total disc replacement under a range of in vitro test conditions

Abstract

The effect of kinematics, loading and centre of rotation on the wear of an unconstrained total disc replacement have been investigated using the ISO 18192‐1 standard test as a baseline. Mean volumetric wear rate and surface morphological effects were reported. Changing the phasing of the flexions to create a low (but finite) amount of crossing path motion at the bearing surfaces resulted in a significant fall in wear volume. However, the rate of wear was still much larger than previously reported values under zero cross shear conditions. Reducing the load did not result in a significant change in wear rate. Moving the centre of rotation of the disc inferiorly did significantly increase wear rate. A phenomenon of debris re‐attachment on the UHMWPE surface was observed and hypothesised to be due to a relatively harsh tribological operating regime in which lubricant replenishment and particle migration out of the bearing contact zone were limited. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 46–52, 2017.

Development of a Biconcave Mobile‐Bearing Lumbar Total Disc Arthroplasty Concept Using Finite Element Analysis and Design Optimization

“…b), and a biconvex design (with the same radii of curvature of 11 mm on both MoP articulations, and a PE rim thickness of 2.5 mm; Fig. c), were modeled. They were inserted into the intradiscal space of the L3–L4 segment model (Fig.…”

Wear properties of poly‐ether‐ether‐ketone bearing combinations under zero and cross shear kinematics in total knee arthroplasty

“…Metal-on-Polyethylene (M-on-P) is currently the gold standard for 35 total knee replacements (TKR) forming 82.3 % of all cemented TKRs in 2015-2016 1 . 36 However, wear of the UHMWPE component remains a concern 2 . 37 UHMWPE wear debris is a major contributing factor in osteolysis (bone loss), leading to 38 aseptic loosening, documented as the primary reason for failure in 40.2 % of knee 39 replacements, reducing the longevity of the implant 1,3 .…”