The purpose of this study was to compare the two-dimensional with three-dimensional radiographic measurements of polyethylene liner wear in the Harris-Galante II acetabular cup.

We measured the polyethylene liner wear amount and the wear rate of 64 hips with Harris-Galante II acetabular cup by two methods: Livermore's method and modified Devane's method. We evaluated the relationships between the two methods.

The average total amount of wear and the average wear rate are 0.86±1.01 mm and 0.18±0.20 mm/year using the two-dimensional method and 0.99±1.01 mm and 0.21±0.2 mm/year using three-dimensional method respectively. The amount of wear and the wear rate by the three-dimensional method was larger than those by the two dimensional method.

The amount of polyethylene liner wear can be measured by the two-dimensional method because it is highly correlated with the amount that is measured by the three-dimensional method, since there was no differences between the two methods.