Ceramic Heads Decrease Metal Release Caused by Head-taper Fretting and Corrosion

Abstract

BackgroundMetal release resulting from taper fretting and corrosion is a clinical concern, because wear and corrosion products may stimulate adverse local tissue reactions. Unimodular hip arthroplasties have a conical taper between the femoral head (head bore taper) and the femoral stem (stem cone taper). The use of ceramic heads has been suggested as a way of reducing the generation of wear and corrosion products from the head bore/stem cone taper junction. A previous semiquantitative study found that ceramic heads had less visual evidence of fretting-corrosion damage compared with CoCr heads; but, to our knowledge, no studies have quantified the volumetric material loss from the head bore and stem cone tapers of a matched cohort of ceramic and metal heads.Questions/purposesWe asked: (1) Do ceramic heads result in less volume of material loss at the head-stem junction compared with CoCr heads; (2) do stem cone tapers have less volumetric material loss compared with CoCr head bore tapers; (3) do visual fretting-corrosion scores correlate with volumetric material loss; and (4) are device, patient, or intraoperative factors associated with volumetric material loss?MethodsA quantitative method was developed to estimate volumetric material loss from the head and stem taper in previously matched cohorts of 50 ceramic and 50 CoCr head-stem pairs retrieved during revision surgery for causes not related to adverse reactions to metal particles. The cohorts were matched according to (1) implantation time, (2) stem flexural rigidity, and (3) lateral offset. Fretting corrosion was assessed visually using a previously published four-point, semiquantitative scoring system. The volumetric loss was measured using a precision roundness machine. Using 24 equally spaced axial traces, the volumetric loss was estimated using a linear least squares fit to interpolate the as-manufactured surfaces. The results of this analysis were considered in the context of device (taper angle clearance, head size, head offset, lateral offset, stem material, and stem surface finish) and patient factors that were obtained from the patients’ operative records (implantation time, age at insertion, activity level, and BMI).ResultsThe cumulative volumetric material losses estimated for the ceramic cohort had a median of 0.0 mm3 per year (range, 0.0–0.4 mm3). The cumulative volumetric material losses estimated for the CoCr cohort had a median of 0.1 mm3 per year (range, 0.0–8.8 mm3). An order of magnitude reduction in volumetric material loss was found when a ceramic head was used instead of a CoCr head (p < 0.0001). In the CoCr cohort, the femoral head bore tapers had a median material loss of 0.02 mm3 (range, 0.0–8.7 mm3) and the stem cone tapers had a median material loss of 0.0 mm3 (range, 0.0–0.32 mm3/year). There was greater material loss from femoral head bore tapers compared with stem cone tapers in the CoCr cohort (p < 0.001). There was a positive correlation between visual scoring and volumetric material loss (Spearman’s ρ = 0.67, p < 0.01). Alth...

Trunnion Failure of the Recalled Low Friction Ion Treatment Cobalt Chromium Alloy Femoral Head

“…Black synovial fluid from a hip aspiration appears to be associated with impending GTF requiring a complete revision of the femoral stem as compared to a femoral head and liner exchange, allowing appropriate preoperative planning. Based on this experience, we have changed our clinical practice from using CoCr femoral heads to ceramic heads based on the lower risk of corrosion and metal release[29, 30], which should theoretically mitigate ALTR issues in the future.…”

Do Stem Taper Microgrooves Influence Taper Corrosion in Total Hip Arthroplasty? A Matched Cohort Retrieval Study

“…However, a weaker correlation has been observed with the more severely damaged femoral head bores, specifically those with a score of 3 or 4 [23, 24]. To compare the material loss between the smaller cohort of the 14 most highly damaged implants, we chose to describe the maximum depth of material loss of these components by calculating the best fit of the femoral head bore at different z heights along the taper.…”

Reducing fretting‐initiated crevice corrosion in hip simulator tests using a zirconia‐toughened alumina femoral head

“…In particular, ceramic femoral heads are suitable to be used as the articulating surface in THAs due to their hardness and wettability, lower friction, and higher wear resistance . Several retrieval studies recently reported that metal fretting and corrosion from the head–neck junction may be mitigated by using a ceramic femoral head . Moreover, alumina and ZTA ceramics have high chemical stability, such as high corrosion resistance.…”

“…11,12 Several retrieval studies recently reported that metal fretting and corrosion from the head-neck junction may be mitigated by using a ceramic femoral head. 14,15 Moreover, alumina and ZTA ceramics have high chemical stability, such as high corrosion resistance. It has also been suggested that Ti-6Al-4V alloy stem neck tapers may cause more galvanic corrosion than Co-Cr-Mo stem neck tapers when used in conjunction with a Co-Cr-Mo femoral head.…”