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©The Author(s) 2015.
World J Orthop. Jan 18, 2015; 6(1): 77-94
Published online Jan 18, 2015. doi: 10.5312/wjo.v6.i1.77
Published online Jan 18, 2015. doi: 10.5312/wjo.v6.i1.77
Table 1 Geometrical characteristics of hip implants: head diameter Dh and diametrical clearance Cl
Head/cup | Dh (mm) | Cl (μm) |
MoP | 22.2-44 | 160-400 |
CoP | 22.2-36 | 160-400 |
MoM | 22.2-54 | 50-150 |
MoMRHR | 42-62 | 50-300 |
CoC | 22.2-44 | 20-100 |
Table 2 Implant material properties: Young’s modulus E, Poisson’s ratio v and surface roughness Ra
Material | E (GPa) | n | Ra (μm) | |
P | UHMWPE | 0.5-1 | 0.4 | 0.1-2 |
M | CoCrMo | 230 | 0.3 | 0.01-0.05 |
C | Biolox delta | 350 | 0.26 | 0.001-0.005 |
Head/cup | COF 25% Bovine serum | COF 100% Bovine serum |
MoP | 0.062 (+ 0.008) | 0.064 (± 0.01) |
CoP | 0.056 (+ 0.01) | 0.06 (± 0.012) |
MoM | 0.12 (± 0.02) | 0.096 (± 0.012) |
MoMRHR | 0.098 (± 0.02) | 0.079 (± 0.011) |
CoC | 0.04 (+ 0.007) | 0.056 (± 0.01) |
Table 4 Theoretical estimation of the lubrication regime according to equation (17)
Head/cup | hmin (μm) | Ra (μm) | λ | Lubricationregime |
MoP | 0.065-0.144 (0.105) | 0.1-2 | 0.1-1 | Boundary to Mixed |
CoP | 0.076-0.107 (0.092) | 0.1-2 | 0.05-0.9 | Boundary to Mixed |
MoM | 0.020-0.061 (0.041) | 0.014-0.071 | 0.6-2.9 | Boundary to Mixed |
MoMRHR | 0.082-0.049 (0.066) | 0.014-0.071 | 0.9-4.6 | Boundary to Fluid-film |
CoC | 0.035-0.045 (0.04) | 0.0014-0.0071 | 5.7-28.3 | Fluid-film |
Table 5 Typical wear rates reported in clinical studies (when available, the average value is indicated in the brackets)
Head/cup | hclin (μm/Mc) | Vclin (mm3/Mc) |
MoP | 50-500 (50) | 10-500 (80) |
CoP | 30-150 | 15-50 |
MoM (RI) | 1-50 | 0.1-25 |
MoM (SS) | 0.1-1 | 0.05-4 |
MoMRHR (RI + SS) | 0.2-10 | 0.2-2.9 |
MoMRHR (ADT) | 1.5-46 | 0.2-95 |
CoC | 0.01-1 | 0.005-2 |
- Citation: Puccio FD, Mattei L. Biotribology of artificial hip joints. World J Orthop 2015; 6(1): 77-94
- URL: https://www.wjgnet.com/2218-5836/full/v6/i1/77.htm
- DOI: https://dx.doi.org/10.5312/wjo.v6.i1.77