Measurements of cobalt chrome plates taken with a Taylor Hobson contacting form talysurf perpendicular to the direction of damage simulation, data relating to Table 4 in the manuscript. The values shown are the mean roughness of each plate, 5 traces were taken for each plate post-damage simulation. For the negative controls, the roughness values of the plates at the start of the wear study have been included, no primary analysis was carried out on these measurements. PGCS: Pharmaceutical grade of calcium sulfate: Stimulan (Biocomposites Ltd, Keele) MGCS: Medical grade of calcium sulfate: Osteoset (Wright Medical Technology, TN, USA) PMMA: SmartSet GMV Gentamicin bone cement (DePuy Synthes, IN, USA) For the roughness (R) values, filtering was applied to measurements as per ISO 4288:1998 (Roughness values) Ra Sample Negative control Positive control PGCS MGCS PMMA 1 0.004 0.222 0.005 0.004 0.004 2 0.006 0.214 0.004 0.010 0.004 3 0.007 0.219 0.004 0.008 0.007 4 0.003 0.003 0.008 Rp Sample Negative control Positive control PGCS MGCS PMMA 1 0.015 1.375 0.027 0.024 0.013 2 0.021 1.410 0.014 0.045 0.019 3 0.029 1.296 0.033 0.054 0.033 4 0.016 0.015 0.044 Rv Sample Negative control Positive control PGCS MGCS PMMA 1 0.011 1.701 0.014 0.013 0.013 2 0.017 1.627 0.011 0.028 0.014 3 0.019 1.685 0.010 0.018 0.019 4 0.009 0.011 0.018 For the primary analysis, no filtering applied to measurements (P values) Pa Sample Negative control Positive control PGCS MGCS PMMA 1 N/A 0.247 0.053 0.044 0.049 2 N/A 0.226 0.053 0.161 0.068 3 N/A 0.257 0.102 0.077 0.054 4 0.020 0.041 0.128 Pp Sample Negative control Positive control PGCS MGCS PMMA 1 N/A 2.461 0.154 0.148 0.101 2 N/A 2.404 0.123 0.279 0.125 3 N/A 2.596 0.216 0.273 0.133 4 0.074 0.150 0.242 Pv Sample Negative control Positive control PGCS MGCS PMMA 1 N/A 3.152 0.142 0.131 0.144 2 N/A 3.099 0.167 0.552 0.232 3 N/A 3.256 0.339 0.308 0.166 4 0.066 0.138 0.366