title: [Detection of metal ions in hair after metal-metal hip arthroplasty].
abstract: OBJECTIVE
  There is an increase in the levels of metals in the serum and urine after the implantation of some models of metal-metal hip prosthesis. It has recently been demonstrated that there is an association between these levels and the levels found in hair. The aim of this study is to determine the presence of metals in hair, and to find out whether these change over time or with the removal of the implant.
  
  
  METHODS
  The levels of chromium, cobalt and molybdenum were determined in the hair of 45 patients at 3, 4, 5, and 6 years after a hip surface replacement. The mean age was 57.5 years, and two were female. Further surgery was required to remove the replacement and implant a new model with metal-polyethylene friction in 11 patients, 5 of them due to metallosis and a periarticular cyst.
  
  
  RESULTS
  The mean levels of metals in hair were chromium 163.27 ppm, cobalt 61.98 ppm, and molybdenum 31.36 ppm, much higher than the levels found in the general population. A decrease in the levels of chromium (43.8%), molybdenum (51.1%), and cobalt (91.1%) was observed at one year in the patients who had further surgery to remove the prosthesis.
  
  
  CONCLUSIONS
  High concentrations of metals in the hair are observed in hip replacements with metal-metal friction, which decrease when that implant is removed. The determination of metal ions in hair could be a good marker of the metal poisoning that occurs in these arthroplasty models.
authors.affiliation: Servicio de Cirugía Ortopédica y Traumatología, Hospital San Agustín, Avilés, Departamento de Cirugía, Facultad de Medicina, Universidad de Oviedo, España. Electronic address: danielhvaquero@gmail.com.
authors.forename: D
authors.initials: D
authors.lastname: Hernandez-Vaquero
authors.affiliation: Servicio de Farmacia Hospitalaria, Hospital San Agustín, Avilés, España.
authors.forename: M
authors.initials: M
authors.lastname: Rodríguez de la Flor
authors.affiliation: Unidad de Investigación, Hospital San Agustín, Avilés, España.
authors.forename: J M
authors.initials: JM
authors.lastname: Fernandez-Carreira
authors.affiliation: Unidad de Espectrometría de Masas, Servicios Científico-Técnicos de Investigación, Universidad de Oviedo, Oviedo, España.
authors.forename: C
authors.initials: C
authors.lastname: Sariego-Muñiz
mesh_terms: D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip; D002857:Chromium / Q000032:analysis*; D003035:Cobalt / Q000032:analysis*; D005260:Female; D006197:Hair / Q000737:chemistry*; D006801:Humans; D008297:Male; D061825:Metal-on-Metal Joint Prostheses; D008875:Middle Aged; D008982:Molybdenum / Q000032:analysis*; D013997:Time Factors
chemical_list: D002857:Chromium; D003035:Cobalt; D008982:Molybdenum
keywords: Artroplastias de superficie de cadera; Hip surface replacement; Metal-metal prosthesis; Metales en cabello; Metals in hair; Prótesis metal-metal