What is the Trouble With Trunnions?

Abstract

Background Recent studies have attributed adverse local tissue reactions (ALTRs) in patients with total hip arthroplasties (THAs) to tribocorrosion debris generated by modular femoral stems. The presentations of ALTR are diverse, as are the causes of it, and the biological responses can be important reasons for failure after THA.

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

“…It is clear, however, based on our observations of severe fretting and corrosion damage among heads and stems with both smooth and micro-grooved tapers (e.g., Figures 2 and 3), that independent modification of taper surface morphology alone is unlikely to present a promising solution for fretting corrosion damage. Furthermore, based on the results of this study, it likewise appears implausible that historical changes in taper surface morphology are responsible for today’s renewed clinical concern with taper fretting corrosion [10]. …”

“…Among the numerous clinical and implant variables associated with visual evidence of MACC damage in previous retrieval studies, researchers have identified the following contributing factors: implantation time; flexural rigidity and length of the femoral stem taper; mixing of alloys between the head and stem; and incorporating multiple modularity into the stem, for example a modular neck [7–9]. Regardless of the etiology and ubiquity of MACC, there appears to have been only a small number of patients developing clinically significant adverse local tissue reactions from the release of metal ions and corrosion products from taper interfaces [10]. The reasons underlying a patient’s specific response to metal ions and corrosion products remain poorly understood.…”

A High Prevalence of Corrosion at the Head–Neck Taper with Contemporary Zimmer Non-Cemented Femoral Hip Components

“…Until recently [9], soft-tissue reactions have been reported only sporadically, and are thought to occur when ionic and molecular products are produced when mechanically assisted crevice corrosion (MACC) occurs at metal/metal modular junctions in which at least one of the components is fabricated from cobalt-chromium alloy [2]. A recent systematic literature review concluded that "a noticeable increase in ALTR as a reason for revision surgery did not start until 2010" [9] but the prevalence is unknown [10]. We found a corrosion prevalence of 1.1 percent in a consecutive series of contemporary Zimmer (Zimmer, Inc., Warsaw, IN) non-cemented femoral hip components followed for a minimum of 2 years.…”

“…All stems are manufactured by the Zimmer company (Zimmer, Inc., Warsaw, IN, USA) as were 8 of the 10 reported by Cooper and colleagues [1] in 2012. Our patients' stems all had a 12/14 taper, although this style taper has been in use for over 20 years [9] and recent retrieval analysis has determined that it has moderate flexural rigidity [13]. Our cohort had a variety of head sizes, stem offsets, and acetabular liner styles-although longevity highly crosslinked polyethylene (Zimmer, Inc., Warsaw, IN, USA) was used in all cases.…”

Tribocorrosion in shoulder arthroplasty humeral component retrievals

“…1,12 Many different factors are thought to be associated with tribocorrosion, including head size, head offset, head angle, flexural rigidity of the neck, dissimilar alloy pairings, and dimensions of the modular taper connection itself. 7 Modularity is also widely used in shoulder arthroplasty implants. However, retrieval studies of shoulder implants are much sparser in the literature than for hip or knee implants.…”