title: Metal ion levels in large-diameter total hip and resurfacing hip arthroplasty--preliminary results of a prospective five year study after two years of follow-up.
abstract: BACKGROUND
  Metal-on-metal hip resurfacing is an alternative to metal-on-metal total hip arthroplasty, especially for young and physically active patients. However, wear which might be detected by increased serum ion levels is a matter of concern.
  
  
  METHODS
  The aims of this preliminary study were to determine the raise of metal ion levels at 2-years follow-up in a prospective setting and to evaluate differences between patients with either resurfacing or total hip arthroplasty. Furthermore we investigated if the inclination of the acetabular component and the arc of cover would influence these findings. Therefore, 36 patients were followed prospectively.
  
  
  RESULTS
  The results showed increments for Co and Cr in both implant groups. Patients treated with large-diameter total hip arthroplasty showed fourfold and threefold, respectively, higher levels for Co and Cr compared to the resurfacing group (Co: p < 0,001 and Cr: p = 0,005). Nevertheless, we observed no significant correlation between serum ion levels, inclination and arc of cover.
  
  
  CONCLUSIONS
  In order to clarify the biologic effects of ion dissemination and to identify risks concerning long-term toxicity of metals, the exposure should be monitored carefully. Therefore, long-term studies have to be done to determine adverse effects of Co and Cr following metal-on-metal hip replacement.
authors.affiliation: Department of Orthopaedic Surgery, Medical University of Graz, Graz, Austria.
authors.forename: W
authors.initials: W
authors.lastname: Maurer-Ertl
authors.forename: J
authors.initials: J
authors.lastname: Friesenbichler
authors.forename: P
authors.initials: P
authors.lastname: Sadoghi
authors.forename: M
authors.initials: M
authors.lastname: Pechmann
authors.forename: M
authors.initials: M
authors.lastname: Trennheuser
authors.forename: A
authors.initials: A
authors.lastname: Leithner
mesh_terms: D000077:Acetabulum / Q000000981:diagnostic imaging / Q000601:surgery; D000328:Adult; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects / Q000295:instrumentation*; D002857:Chromium / Q000097:blood*; D003035:Cobalt / Q000097:blood*; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000601:surgery; D005500:Follow-Up Studies; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000601:surgery*; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011474:Prosthesis Design; D011859:Radiography; D013997:Time Factors; D016896:Treatment Outcome; D014800:Vitallium
chemical_list: D002857:Chromium; D014800:Vitallium; D003035:Cobalt