Backside wear of tibial polyethylene components is affected by gait pattern: A knee simulator study using rare earth tracer technology

Abstract

The aim of this study was to determine the effect of two in‐vivo–determined gait patterns, one with low and one with high anteroposterior (AP) motion, on total and backside polyethylene insert wear in comparison with the ISO (International Organization for Standardization) standard 14243‐3. In order to differentiate and accurately quantify topside and backside wear, a novel technique was employed where different lanthanide tracers were incorporated into the polyethylene during manufacture. Wear particle analysis was conducted following established protocols. For all tested liners and motion protocols, the chemically calculated wear rates correlated closely with gravimetrically determined wear. Both in vivo motion groups displayed higher wear rates than the ISO group following the order of the AP motion amplitudes. Backside wear for ISO constituted 2.76% ± 0.90% (mean ± SE) of the total wear, increasing significantly to 15.8% ± 3.2% for the low AP and further increasing to 19.3% ± 0.95% for the high AP motion protocol. The mean wear particle sizes were under 200 nm for all three motion patterns, being largest for the protocol with high AP motion. Particle release from the low and high AP gait patterns was 1.9 to 2.8 times that from the ISO protocol. Testing for the proportion of backside wear across various activities of daily living should be an important consideration in evaluating knee prostheses wear.

Joint line elevation and tibial slope are associated with increased polyethylene wear in cruciate‐retaining total knee replacement

“…The actual impact on the wear volume is unknown; however, based on a simulator study of the same design, it can be estimated that backside damage contributes between 3 and 20% to the total wear of the insert. 39 Overall, it appears that backside damage is composed to a large degree of plastic deformation and not necessarily material loss. Smaller inserts exhibit a larger degree of damage.…”

Towards the understanding of lubrication mechanisms in total knee replacements – Part I: Experimental investigations

“…Generally speaking, the wear performance of TKA depends on in vivo loading, design factors of the implant, and surgical and patient-specific factors. For example, polyethylene damage in a TKA may depend on gait characteristics [18] or the locking mechanism of the polyethylene insert in the metal tray [19]. Despite all the technological developments, the material characteristics of the implant play an important role [20].…”

Is Wear Still a Concern in TKA With Contemporary Conventional and Highly Crosslinked Polyethylene Tibial Inserts in the Mid- to Long-Term?

“…Osteolysis presents with obvious osteolytic lesions/bony changes on preoperative radiographs (29), while PE wear cases undergo delamination with material loss most commonly identified intraoperatively. Osteolysis is frequently driven by a foreign body particle response to small particles on the scale of tens to hundreds of nanometers (29)(30)(31). Particles trigger a macrophage response that can initiate a cascade of cell responses resulting in periprosthetic bone loss and loosening.…”