title: Medium-term results following large diameter metal-on-metal total hip arthroplasty: increasing failure after 6 years.
abstract: OBJECTIVE
  The main aim of our study is to report the medium-term survivorship of Birmingham Hip Resurfacing (BHR) cup and a large modular metal head (MMT) on an uncemented Freeman femoral stem. No results have been reported till date with these implants combinations.
  
  
  METHODS
  A total of 205 metal-on-metal total hip replacements (MoM THRs) were performed on 190 patients from October 2002 to November 2004. Prior to the Medicines and Healthcare Products Regulatory Agency (MHRA) guidelines, the patients were followed up at 3, 6 and 12 months postoperatively and annually thereafter. Following the MHRA alert in 2010, the patients were followed-up as per the MHRA guidelines.All statistical analyses were conducted using Stata 13.
  
  
  RESULTS
  At a mean follow-up of 10.5 years, a total of 42 out of 205 hips were revised for reasons related to ALTR. The failure rates increased significantly over time (7% at 6 years and 29% at 10-year follow-up). The analysis showed no statistically significant association to age, gender, side, BMI or component size or position (p&lt;0.05). Blood metal ions showed a poor discriminant ability to separate failed from well-functioning MoM hip replacements.
  
  
  CONCLUSIONS
  Large head MoM BHR on an uncemented stem has extremely high failure rate. The authors do not recommend the use of large head MoM articulation in total hip arthroplasty in the wake of this report and similar findings across the world. Continued surveillance of these implants is required as the failure rates increase with time.
authors.affiliation: Trauma and Orthopaedics Department, Royal Liverpool and Broadgreen University Hospitals NHS Trust, Liverpool - UK.
authors.forename: Satish V
authors.initials: SV
authors.lastname: Dhotare
authors.affiliation: Trauma and Orthopaedics Department, Royal Liverpool and Broadgreen University Hospitals NHS Trust, Liverpool - UK.
authors.forename: Deepak G
authors.initials: DG
authors.lastname: Shivarathre
authors.affiliation: Trauma and Orthopaedics Department, Royal Liverpool and Broadgreen University Hospitals NHS Trust, Liverpool - UK.
authors.forename: Cristina
authors.initials: C
authors.lastname: Croitoru
authors.affiliation: Trauma and Orthopaedics Department, Royal Liverpool and Broadgreen University Hospitals NHS Trust, Liverpool - UK.
authors.forename: Catherine
authors.initials: C
authors.lastname: Armstrong
authors.affiliation: Trauma and Orthopaedics Department, Royal Liverpool and Broadgreen University Hospitals NHS Trust, Liverpool - UK.
authors.forename: Birender
authors.initials: B
authors.lastname: Kapoor
authors.affiliation: Trauma and Orthopaedics Department, Royal Liverpool and Broadgreen University Hospitals NHS Trust, Liverpool - UK.
authors.forename: Viju K
authors.initials: VK
authors.lastname: Peter
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects* / Q000379:methods; D015331:Cohort Studies; D016001:Confidence Intervals; D005260:Female; D005500:Follow-Up Studies; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D061825:Metal-on-Metal Joint Prostheses / Q000009:adverse effects*; D008875:Middle Aged; D015999:Multivariate Analysis; D016016:Proportional Hazards Models; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012086:Reoperation / Q000379:methods; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome