title: Poor short term outcome with a metal-on-metal total hip arthroplasty.
abstract: Metal-on-metal (MoM) bearings for total hip arthroplasty (THA) have come under scrutiny with reports of high failure rates. Clinical outcome studies with several commercially available MoM THA bearings remain unreported. We evaluated 78 consecutive MoM THAs from a single manufacturer in 68 patients. Sixty-six received cobalt-chrome (CoCr) monoblock and 12 received modular titanium acetabular cups with internal CoCr liners. Femoral components were titanium with modular necks. At average 2.1 years postoperatively, 12 THAs (15.4%) demonstrated aseptic failure (10 revisions, 2 revision recommended). All revised hips demonstrated capsular necrosis with positive histology reaction for aseptic lymphocytic vasculitis-associated lesions/adverse local tissue reactions. Prosthetic instability following revision surgery was relatively common. Female gender was a strong risk factor for failure, though smaller cups were not. Both monoblock and modular components fared poorly. Corrosion was frequently observed around the proximal and distal end of the modular femoral necks.
authors.affiliation: Shiley Center for Orthopaedic Research and Education at Scripps Clinic, La Jolla, CA, USA.
authors.forename: Yadin D
authors.initials: YD
authors.lastname: Levy
authors.forename: Kace A
authors.initials: KA
authors.lastname: Ezzet
mesh_terms: D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation*; D002857:Chromium; D003035:Cobalt; D003343:Corrosion; D005260:Female; D005549:Foreign-Body Reaction / Q000453:epidemiology*; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008670:Metals; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology*; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012086:Reoperation; D012307:Risk Factors; D012737:Sex Factors; D014025:Titanium
chemical_list: D008670:Metals; D002857:Chromium; D003035:Cobalt; D014025:Titanium
keywords: aseptic loosening; large diameter total hip arthroplasty; metal-on-metal