Metal Ion Levels and Clinical Outcomes of Ceramic-on-Metal Were Same as Ceramic-on-Ceramic THA

Introduction:Whole blood metal ion level and clinical outcomes of ceramic-on-metal bearing were comparable to ceramic-on-ceramic THA in this prospective randomized controlled trial.Methods:We randomized 150 consecutive THA cases at one institution into two groups: Group I and Group II. Group I, 75 cases, received a THA using ceramic-on-metal couplings and Group II, 75 cases, received ceramic-on-ceramic bearing THA. The implant differed only in the bearing surfaces used. We compared the serum levels of cobalt (Co) and chromium (Cr) and functional outcome scores preoperatively, and at 2, 6, and 12 months postoperatively.Results:The demographics and preoperative Co and Cr levels were similar between the groups. Femoral head size measured 32 and 36 mm and the proportion of each size was similar in both groups. The mean serum cobalt and chromium levels increased significantly at 2 months in Group I (Co p = 0.02, Cr p = 0.04), but no differences noted between groups at 6 and 12 months (Co p > 0.05, Cr p > 0.05)...