Trunnion Failure of the Recalled LFIT Cobalt Chromium Alloy Femoral Head

Abstract Background Gross trunnion failure (GTF) is a rare complication in total hip arthroplasty reported across a range of manufacturers. Specific lots of the Stryker LFIT Anatomic cobalt chromium alloy (CoCr) V40 femoral head were recalled in August of 2016. In part, the recall was based out of c...

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Bibliographic Details
Published in:The Journal of arthroplasty 2017-04, Vol.32 (9), p.2857-2863
Main Authors: Urish, Kenneth L., MD PhD, Hamlin, Brian R., MD, Plakseychuk, Anton Y., MD PhD, Levison, Timothy J., MS, Higgs, Genymphas, Kurtz, Steven, DiGioia, Anthony M., MD
Format: Article
Language:English
Subjects:
Orthopedics
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Summary:Abstract Background Gross trunnion failure (GTF) is a rare complication in total hip arthroplasty reported across a range of manufacturers. Specific lots of the Stryker LFIT Anatomic cobalt chromium alloy (CoCr) V40 femoral head were recalled in August of 2016. In part, the recall was based out of concerns for disassociation of the femoral head from the stem and GTF. Methods We report on 28 patients (30 implants) with either GTF (n=18) or head-neck taper corrosion (n=12) of the LFIT CoCr femoral head and the Accolade TMZF femoral stems. All of these cases were associated with adverse local tissue reaction (ALTR) requiring revision of the THA. Results In our series, a conservative estimate of the incidence of failure was 4.7% (n = 636 total implanted) at 8.0±1.4 years from the index procedure. Failures were associated with a high offset 127° femoral stem neck angle and increased neck lengths. 43.3% (13/30) of the observed failures included implant sizes outside of the voluntary recall (27.8% (5/18) of the GTF and 75.0% (8/12) of the taper corrosion cases). Serum cobalt and chromium levels were elevated (Cobalt: 8.4±7.0μg/mL; Chromium: 3.4±3.3μ/L; Cobalt/Chromium ratio: 3.7). MARS MRI demonstrated large cystic fluid collections typical with ALTR. During revision, a pseudotumor was observed in all cases. Pathology suggested a chronic inflammatory response. Impending GTF could be diagnosed based on aspiration of black synovial fluid and an oblique femoral head as compared to the neck taper on radiographs. Conclusion In our series of the recalled LFIT CoCr femoral head, the risk of impending GTF or head-neck taper corrosion should be considered as a potential diagnosis in a painful Accolade TMZF THA with unknown etiology. Almost half of the failures we observed included sizes outside of the voluntary recall. Level of Evidence Diagnostic Level III;
ISSN:0883-5403
1532-8406
DOI:10.1016/j.arth.2017.03.075