About the relevance of roughness parameters used for characterizing worn femoral heads

Abstract

is an open access repository that collects the work of Arts et Métiers ParisTech researchers and makes it freely available over the web where possible. AbstractThis study aims to contribute to the definition of a methodology, which can help to select a relevant roughness parameter with a view to describing the topography of orthopaedic bearing surfaces. In this investigation, the surface topography of a retrieved titanium alloy (TA6V) femoral head was characterized using visual inspection, optical microscopy and three-dimensional contacting profilometry. A numerical analysis of roughness measurements was then undertaken to assess in a first step the values of different roughness parameters of interest found in papers dealing with the topography of orthopaedic bearing surfaces. In a second step, the Analysis of Variance (ANOVA) and the Computer-Based Bootstrap Method were combined to determine statistically, and without preconceived opinion, which of those parameters is the most relevant to describe the different investigated worn regions of the studied femoral head.

Understanding the dual mobility concept for total hip arthroplasty. Investigations on a multiscale analysis-highlighting the role of arthrofibrosis

“…The evolution of the roughness parameters was fruitful for isolating the particular wear zones and for pointing out the significant wear zones. The specific methodology dedicated to this study was established from [24][25][26][27][28]. Thus, in order to characterize quantitatively the wear mechanism at a microscale, the following analyses were practised: analyses of 11 zones on the convex side of each UHMWPE liner, i.e.…”

“…All parameters were defined in [26] and in ISO standard 25178. As example, the Figure 3a shows the evolution of Sa according to the liner type and the Figure 3b.…”

May the surface roughness of the retrieved femoral head influence the wear behavior of the polyethylene liner?

“…Actually, we primarily wonder whether the roughness of the femoral head could influence the wear of the UHMWPE acetabular cup: if one considers the Ra values, this study has failed as we measured Ra values of the same order of magnitude for the metallic and ceramic heads although Rsk values (Table II) and volumetric losses obtained by CMM measurements were significantly different, as well as the trend of the spectroscopic markers (Table III). The inadequacy of the Ra parameter did not appear unexpected as it has been reported to fail to discriminate the topographies of severely scratched regions, 18 also owing to the sampling problems in the obtainment of representative roughness data. 15,16 On the other hand, the data summarized in Table II showed that the ceramic heads were characterized by significantly more negative Rsk values than the metallic ones, suggesting the presence of a larger number of scratches in the former.…”

“…On the other hand, the choice of the most relevant roughness parameter to be used for assessing the surface topography of retrieved femoral heads is a still debated subject. 16,18,19 In this context, the main goal of this study was the examination of the surface of retrieved ceramic and metallic femoral heads to gain more insights into the influence of the femoral head degradation on the wear of the UHMWPE acetabular counterface. The novelty of this study lies in the approach used as the hip components were analyzed both at the macroscopic and at the molecular levels.…”

Multiscale roughness analysis of engineering surfaces: A comparison of methods for the investigation of functional correlations

“…Bootstrapping is also used to estimate the error of the mean roughness parameters, called p i;k ðF; T; ε; j; n j Þ, where k denotes the bootstrap number [48].…”