The surface topography of 11 alumina-on-alumina hip arthroplasties retrieve
d for aseptic loosening at a mean Ii-year followup was investigated. Macros
copic wear was assessed using a coordinate measuring machine, Microscopic w
ear features were evaluated by Talysurf analysis. Scanning electron microsc
opy was used to look at the alumina microstructure, Components were classif
ied into three groups: (1) low wear with no sign of wear and average arithm
etic roughness values below 0.05 mu m; (2) stripe wear with a visible oblon
g worn area on the femoral heads and penetration rates below 10 mu m/year;
and (3) severe wear with a visible loss of material on both components, sho
wing total roughness values as much as 4 mu m and maximum penetrations high
er than 150 mu m. Alumina quality assessed by grain size measurements and p
orosity percentages improved progressively from 1977 to 1988. This resulted
in a correlated decrease of the microscopic wear magnitude, However, on a
macroscopic scale, factors responsible for either a load increase (weight,
young age, and male gender) or impairment in the load distribution over the
component surfaces (large grain size, nonoptimal initial cup inclination,
and cup migration and/or tilting) increased the penetration rates.