title: What Are Normal Metal Ion Levels After Total Hip Arthroplasty? A Serologic Analysis of Four Bearing Surfaces.
abstract: The recent experiences with adverse local tissue reactions have highlighted the need to establish what are normal serum levels of cobalt (Co), chromium (Cr), and titanium (Ti) after hip arthroplasty.
  
  
  
  Serum Co, Cr, and Ti levels were measured in 80 nonconsecutive patients with well-functioning unilateral total hip arthroplasty and compared among 4 bearing surfaces: ceramic-on-ceramic (CoC); ceramic-on-polyethylene (CoP); metal-on-polyethylene (MoP), and dual mobility (DM). The preoperative and most recent University of California, Los Angeles (UCLA) and Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores were compared among the different bearing surfaces.
  
  
  
  No significant difference was found among serum Co and Cr levels between the 4 bearing surface groups (P = .0609 and P = .1577). Secondary analysis comparing metal and ceramic femoral heads demonstrated that the metal group (MoP, modular dual mobility (Stryker Orthopedics, Mahwah, NJ) [metal]) had significant higher serum Co levels compared with the ceramic group (CoC, CoP, MDM [ceramic]) (1.05 mg/L ± 1.25 vs 0.59 mg/L ± 0.24; P = .0411). Spearman coefficient identified no correlation between metal ion levels and patient-reported outcome scores.
  
  
  
  No serum metal ion level differences were found among well-functioning total hip arthroplasty with modern bearing couples. Significantly higher serum Co levels were seen when comparing metal vs ceramic femoral heads in this study and warrants further investigation. Metal ion levels did not correlate with patient-reported outcome measures.
authors.affiliation: Division of Adult Reconstruction and Joint Replacement Surgery, Department of Orthopaedic Surgery, Hospital for Special Surgery, New York, New York.
authors.forename: Brian T
authors.initials: BT
authors.lastname: Barlow
authors.affiliation: Division of Adult Reconstruction and Joint Replacement Surgery, Department of Orthopaedic Surgery, Hospital for Special Surgery, New York, New York.
authors.forename: Philippe A
authors.initials: PA
authors.lastname: Ortiz
authors.affiliation: Division of Adult Reconstruction and Joint Replacement Surgery, Department of Orthopaedic Surgery, Hospital for Special Surgery, New York, New York.
authors.forename: John W
authors.initials: JW
authors.lastname: Boles
authors.affiliation: Epidemiology and Biostatistics Core, Hospital for Special Surgery, New York, New York.
authors.forename: Yuo-Yu
authors.initials: YY
authors.lastname: Lee
authors.affiliation: Division of Adult Reconstruction and Joint Replacement Surgery, Department of Orthopaedic Surgery, Hospital for Special Surgery, New York, New York.
authors.forename: Douglas E
authors.initials: DE
authors.lastname: Padgett
authors.affiliation: Division of Adult Reconstruction and Joint Replacement Surgery, Department of Orthopaedic Surgery, Hospital for Special Surgery, New York, New York.
authors.forename: Geoffrey H
authors.initials: GH
authors.lastname: Westrich
mesh_terms: D000368:Aged; D001168:Arthritis / Q000209:etiology; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects* / Q000295:instrumentation; D002516:Ceramics; D002857:Chromium / Q000097:blood*; D003035:Cobalt / Q000097:blood*; D005260:Female; D005500:Follow-Up Studies; D006622:Hip Prosthesis / Q000009:adverse effects*; D006801:Humans; D007477:Ions / Q000097:blood; D008297:Male; D008670:Metals / Q000097:blood*; D008875:Middle Aged; D020959:Polyethylene; D011446:Prospective Studies; D011474:Prosthesis Design; D014025:Titanium / Q000097:blood*
chemical_list: D007477:Ions; D008670:Metals; D002857:Chromium; D003035:Cobalt; D020959:Polyethylene; D014025:Titanium
keywords: ALTR; THR; chromium; cobalt; metal ions