Wear factors of UHMWPE pins for 'Wear and Friction of UHMWPE-on-PEEK-OPTIMA' paper serum conentration (%) 0% 0% 0% 0% 2% 2% 5% 5% 5% 5% 25% 25% 25% 25% 90% 90% 90% 90% Temp rig elevated rig elevated rig rig rig elevated rig elevated rig elevated rig elevated rig elevated rig elevated counterface CoCr PEEK CoCr PEEK CoCr PEEK CoCr PEEK CoCr PEEK 1.1E-08 -2.3E-09 1.6E-08 2.4E-08 1.3E-07 8.1E-08 2.2E-07 1.5E-07 1.3E-07 5.4E-08 2.6E-07 2.4E-07 1.5E-07 7.3E-08 5.0E-07 2.1E-07 1.1E-07 1.2E-07 -4.6E-09 -1.0E-08 1.7E-08 1.3E-08 1.2E-07 1.0E-07 2.1E-07 1.7E-07 1.5E-07 8.0E-08 1.3E-07 1.3E-07 1.7E-07 7.4E-08 4.8E-07 2.5E-07 1.6E-07 3.5E-07 1.4E-10 -7.1E-09 2.8E-08 2.9E-08 2.0E-07 1.1E-07 3.0E-07 1.5E-07 1.1E-07 1.2E-07 1.7E-07 1.9E-07 1.1E-07 1.1E-07 4.7E-07 3.3E-07 2.0E-07 3.1E-07 -3.5E-09 2.8E-08 8.1E-08 4.5E-08 1.6E-07 1.2E-07 5.5E-08 5.3E-08 2.3E-07 1.5E-07 1.2E-07 1.4E-07 2.3E-07 2.0E-07 7.3E-08 8.2E-08 -1.0E-08 2.6E-08 1.7E-07 1.1E-07 1.8E-07 1.3E-07 4.7E-08 3.5E-08 2.7E-07 1.4E-07 3.5E-07 1.2E-07 4.0E-07 2.5E-07 7.4E-08 1.4E-07 -4.2E-09 2.5E-08 1.7E-07 8.6E-08 2.5E-07 2.3E-07 1.0E-07 7.9E-08 2.7E-07 3.1E-07 7.9E-08 4.3E-07 3.4E-07 1.1E-07 9.7E-08