title: Adverse tissue reaction to corrosion at the neck-stem junction after modular primary total hip arthroplasty.
abstract: Complications related to the neck-stem junction of modular stems used for total hip arthroplasty (THA) are generating increasing concern. A 74-year-old male had increasing pain and a cutaneous reaction around the scar 1 year after THA with a modular neck-stem. Imaging revealed osteolysis of the calcar and a pseudo-tumour adjacent to the neck-stem junction. Serum cobalt levels were elevated. Revision surgery to exchange the stem and liner and to resect the pseudo-tumour was performed. Analysis of the stem by scanning electron microscopy and by energy dispersive X-ray and white light interferometry showed fretting corrosion at the neck-stem junction contrasting with minimal changes at the head-neck junction. Thus, despite dry assembly of the neck and stem on the back table at primary THA, full neck-stem contact was not achieved, and the resulting micromotion at the interface led to fretting corrosion. This case highlights the mechanism of fretting corrosion at the neck-stem interface responsible for adverse local tissue reactions. Clinical and radiological follow-up is mandatory in patients with dual-modular stems.
authors.affiliation: Departments of Orthopaedics, Centre Hospitalier Universitaire Vaudois, CHUV, University of Lausanne, Switzerland. Electronic address: Georgios.Gkagkalis@chuv.ch.
authors.forename: G
authors.initials: G
authors.lastname: Gkagkalis
authors.affiliation: Tribology and Interface Chemistry Group, SCI-STI-SM, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland. Electronic address: pierre.mettraux@epfl.ch.
authors.forename: P
authors.initials: P
authors.lastname: Mettraux
authors.affiliation: Departments of Radiology, Centre Hospitalier Universitaire Vaudois, University of Lausanne, Lausanne, Switzerland. Electronic address: Patrick.Omoumi@chuv.ch.
authors.forename: P
authors.initials: P
authors.lastname: Omoumi
authors.affiliation: Tribology and Interface Chemistry Group, SCI-STI-SM, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland. Electronic address: stefano.mischler@epfl.ch.
authors.forename: S
authors.initials: S
authors.lastname: Mischler
authors.affiliation: Departments of Orthopaedics, Centre Hospitalier Universitaire Vaudois, CHUV, University of Lausanne, Switzerland; Schulthess Clinic, Lengghalde 2, 8008 Zurich, Switzerland. Electronic address: Hannes.Ruediger@kws.ch.
authors.forename: H A
authors.initials: HA
authors.lastname: Rüdiger
mesh_terms: D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects*; D005549:Foreign-Body Reaction / Q000175:diagnosis / Q000209:etiology* / Q000601:surgery; D006622:Hip Prosthesis / Q000009:adverse effects*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D015207:Osteoarthritis, Hip / Q000601:surgery; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012086:Reoperation; D014057:Tomography, X-Ray Computed
keywords: Adverse reaction to metal debris; Aseptic lymphocytic vasculitis and associated lesions; Corrosion; Modular stem; Pseudo-tumour; Total hip arthroplasty