Abstract
Purpose: Ceramic/ceramic bearing surfaces have the advantage of significantly decreased wear and high biocompatibility compared to CoCr/PE or ceramic/PE. The purpose of this randomized, controlled, multi-center, prospective study was to evaluate the clinical and roentgenographic results of 469 ceramic/ceramic versus 321 ceramic/PE THA at a 2 to 7 year follow-up.
Methods: The ceramic/ceramic THA had a polished alumina femoral head articulating with a polished alumina acetabular liner seated into the metal acetabular shell designed to avoid any impingement of the ceramic liner on the femoral component. Evaluations were completed preoperatively, at 6 months and yearly postoperatively.
Results: Mean age of the 790 patients was 59 years, with slightly more females. There were no significant demographic differences between the two groups. The main diagnoses were OA in 74% and osteonecrosis in 19%. Preoperatively the mean Harris Hip Score (HHS) and WOMAC scores were 44 and 41, respectively, and did not differ significantly between the two groups. At follow-up, the mean HHS was 93 for the ceramic/ ceramic THA and 93 for the ceramic/PE THA. The mean WOMAC scores showed no differences at follow-up. Roentgenographic analysis revealed one acetabular cup migration with a PE liner. One ceramic liner fractured upon insertion that was not properly positioned prior to impaction. Otherwise, there were no revisions or complications related to either bearing surface.
Conclusions: This short-term study has demonstrated efficacy and safety of a ceramic/ceramic bearing surface compared to the standard ceramic/PE surface currently used in clinical practice, with no failures or complications related to the bearing surface. Further follow-up is indicated to determine the long-term outcome.
Funding : Commerical funding
Funding Parties : Encore Orthopaedics
Correspondence should be addressed to Cynthia Vezina, Communications Manager, COA, 4150-360 Ste. Catherine St. West, Westmount, QC H3Z 2Y5, Canada
