Do Ceramic Femoral Heads Reduce Taper Fretting Corrosion in Hip Arthroplasty? A Retrieval Study

Abstract

BackgroundPrevious studies regarding modular head-neck taper corrosion were largely based on cobalt chrome (CoCr) alloy femoral heads. Less is known about head-neck taper corrosion with ceramic femoral heads.Questions/purposesWe asked (1) whether ceramic heads resulted in less taper corrosion than CoCr heads; (2) what device and patient factors influence taper fretting corrosion; and (3) whether the mechanism of taper fretting corrosion in ceramic heads differs from that in CoCr heads.MethodsOne hundred femoral head-stem pairs were analyzed for evidence of fretting and corrosion using a visual scoring technique based on the severity and extent of fretting and corrosion damage observed at the taper. A matched cohort design was used in which 50 ceramic head-stem pairs were matched with 50 CoCr head-stem pairs based on implantation time, lateral offset, stem design, and flexural rigidity.ResultsFretting and corrosion scores were lower for the stems in the ceramic head cohort (p = 0.03). Stem alloy (p = 0.004) and lower stem flexural rigidity (Spearman’s rho = −0.32, p = 0.02) predicted stem fretting and corrosion damage in the ceramic head cohort but not in the metal head cohort. The mechanism of mechanically assisted crevice corrosion was similar in both cohorts although in the case of ceramic femoral heads, only one of the two surfaces (the male metal taper) engaged in the oxide abrasion and repassivation process.ConclusionsThe results suggest that by using a ceramic femoral head, CoCr fretting and corrosion from the modular head-neck taper may be mitigated but not eliminated.Clinical RelevanceThe findings of this study support further study of the role of ceramic heads in potentially reducing femoral taper corrosion.

No Difference in Reoperations at 2 Years Between Ceramic-on-metal and Metal-on-metal THA: A Randomized Trial

“…One clinical study of metal-on-polyethylene failure has identified a tendency for cobalt levels to increase preferentially to chromium levels when corrosion is a cause of failure [6]. Another study has demonstrated that corrosion is lower with a ceramic to metal taper junction than a metal to metal taper junction [13]. We speculate that lower bearing surface wear and less corrosion may contribute to the stable and comparatively low variability of the CoM cobalt levels.…”

“…A final benefit of this bearing surface is the ceramic head interface with the femoral stem. Retrieval studies have demonstrated lower corrosion at the Morse taper when ceramic heads were used compared with metal heads [13]. The primary concern with a CoM bearing is the metal debris generated at the bearing surface and the potential biologic response.…”

CORR Insights®: Otto Aufranc Award: Large Heads Do Not Increase Damage at the Head-neck Taper of Metal-on-polyethylene Total Hip Arthroplasties

“…(4) What is the effect of factors affecting the frictional forces between the femoral head and the acetabular liner, including surface roughness (third-body damage), clearance of the articulation, and the viscosity of the joint fluid [2]? (5) As most of the material loss in modular joints come from tribo-corrosion of the CoCr head, should metal heads be replaced by ceramic or ''ceramicized'' heads to minimize the problem [7]? Or perhaps surface treatments (ion implantation, nitride, or diamond-like coatings) are a solution.…”

“…Previous studies on this topic have examined relatively small numbers of implants (50 to 80), with conflicting conclusions both in favor [4,7] and against [5] an association between larger heads and increased fretting and/or corrosion of modular head-neck junctions.…”

What is the Trouble With Trunnions?

“…In metal-on-polyethylene (MoP) hips, increased corrosion has been shown in 36-mm metal femoral heads compared with 28-mm heads [16]. Another contributing factor to tribocorrosion in MoP and MoM THAs is the dissimilar alloy pairings of a cobalt-chrome femoral head taper and a titanium trunnion [26], and ceramic femoral heads have been shown to decrease taper tribocorrosion compared with cobalt-chrome heads (CoCr) [20,25,31].…”