RESULTS
Patients in the stainless steel, CoCrMo and Oxinium femoral head groups demonstrated significantly higher HHS scores 10 years postoperatively compared to preoperative scores, and there were no significant differences in clinical function between the three groups (The median blood metal ion levels for Cr, Co, Zr, and Ni were generally low in all study groups (Table Cr, Co, Zr and Ni concentrations in the three groups based on head material (stainless steel, CoCrMo and Oxinium), represented with median, mean and maximum (max) values (microgram/L). Statistical difference between the groups is calculated by Kruskal‐Wallis one‐way testBoxplot of blood metal ion levels (μg/L) for Cr, Co, Zr, and Ni, grouped on head material. Horizontal lines inside the boxes indicates median level. Whiskers represents min‐max values (range). SS, stainless steelSeven patients were revised due to aseptic loosening of either the cup or stem or both. None of the patients in the Charnley group were revised. See table Patients that were revised before 10 years follow‐up due to aseptic loosening of either the cup or stem or both. Three of these cases was included in a retrieval project and whole blood samples collected and the concentration (microgram/L) of Cr, Co, Ni, and Zr measured (study no 819, 831, and 848)Many study patients had prostheses in other joints, surgery performed either before or within the study period (55 of 81), see Supplement 