Figure 3.

Long-term migration of 8 study cohorts. A significant number of patients are often lost at long-term follow-up (10 years); therefore the mean migration may be significantly influenced by an outlier. For example, a patient in the cemented Opticup cohort (retention of sub-subchondral bone) had been radiologically diagnosed with acetabular cup loosening, which may have significantly influenced the mean migration of the cohort. PE = standard polyethylene liner, XLPE = crosslinked-polyethylene liner, CSF = cancellous screw fit.