Authors: Amine Zaoui Samer El Hage Jean Langlois Caroline Scemama Jean Pierre Courpied Moussa Hamadouche
Publish Date: 2015/06/26
Volume: 473, Issue: 12, Pages: 3822-3828
Abstract
Charnley lowfriction torque total hip arthroplasty THA remains the gold standard in THA The main cause for failure is wear of the socket Highly crosslinked polyethylene HXLPE has been associated with reduced wear rates Also oxidized zirconium has shown in vitro reduced wear rates However to our knowledge there are no data comparing oxidized zirconium femoral heads with metal heads against HXLPE or ultrahighmolecularweight polyethylene UHMWPE when 2225mm bearings were used which was the same size that performed so well in Charnleytype THAsWe hypothesized that after a minimal 4year followup 1 use of HXLPE would result in lower radiographic wear than UHMWPE when articulating with a stainless steel head or with an oxidized zirconium head 2 use of oxidized zirconium would result in lower radiographic wear than stainless steel when articulating with UHMWPE and HXLPE and 3 there would be no difference in terms of Merle d’Aubigné scores between the bearing couple combinationsOne hundred patients were randomized to receive cemented THA with either oxidized zirconium or a stainless steel femoral head UHMWPE was used in the first 50 patients whereas HXLPE was used in the next 50 patients There were 25 patients in each of the four bearing couple combinations All other parameters were identical in both groups Complete followup was available in 86 of these patients Femoral head penetration was measured using a validated computerassisted method dedicated to allpolyethylene sockets Clinical results were compared between the groups using the Merle d’Aubigné scoreIn the UHMWPE series the median steadystate penetration rate from 1 year onward was 003 mm/year range 0003–025 mm/year in the oxidized zirconium group versus 011 mm/year range 003–029 mm/year in the metal group difference of medians 008 p 0001 In the HXLPE series the median steadystate penetration rate from 1 year onward was 002 mm/year range −032 to 007 mm/year in the oxidized zirconium group versus 005 mm/year range −039 to 011 mm/year in the metal group difference of medians 003 p 0001 The Merle d’Aubigné scores were no different between the groups with a median of 18 in each of the groups range 16–18This study demonstrated femoral head penetration was reduced by oxidized zirconium when compared with metal on both UHMWPE and HXLPE However apart the metalUHMWE group all other groups had a steadystate penetration rate well below the osteolysis threshold with a low difference between groups that might not be clinically important at this point Longerterm followup is needed to warrant whether wear reduction will generate less occurrence of osteolysis and aseptic loosening
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