title: Metal-on-metal hip resurfacing in osteonecrosis of the femoral head.
abstract: BACKGROUND
  The treatment of end-stage osteonecrosis of the femoral head remains a challenge to the orthopaedic surgeon. Historically, total hip arthroplasty for this condition has been associated with poor rates of survival and function when compared with total hip arthroplasty for the treatment of osteoarthritis. The purpose of this study was to determine the medium-term clinical and radiographic results of metal-on-metal hip resurfacing arthroplasty in patients with end-stage osteonecrosis of the femoral head.
  
  
  METHODS
  From June 1994 to March 2004, a consecutive single-surgeon series of seventy-three hip resurfacing procedures were performed in sixty patients for the treatment of end-stage osteonecrosis of the femoral head. The cohort included forty-two men (ten of whom had a bilateral resurfacing) and eighteen women (three of whom had a bilateral resurfacing). The mean age was forty-three years (range, seventeen to sixty-nine years). A clinical and radiographic review was performed.
  
  
  RESULTS
  There were four revision operations and one planned revision of the seventy-three hips during the follow-up period. Two of these revisions were necessitated by aseptic failure of the femoral component. This represents an overall survival rate of 93.2% at a mean of 6.1 years of follow-up (range, two to twelve years).
  
  
  CONCLUSIONS
  On the basis of this study, metal-on-metal resurfacing of the hip for osteonecrosis can be considered a safe and effective form of surgery for this group of patients. Longer-term follow-up is required to confirm the expected continued success of this form of arthroplasty in this difficult-to-treat population.
  
  
  METHODS
  Therapeutic Level IV. See Instructions to Authors on jbjs.org for a complete description of levels of evidence.
authors.forename: Matthew P
authors.initials: MP
authors.lastname: Revell
authors.forename: Callum W
authors.initials: CW
authors.lastname: McBryde
authors.forename: Sharad
authors.initials: S
authors.lastname: Bhatnagar
authors.forename: Paul B
authors.initials: PB
authors.lastname: Pynsent
authors.forename: Ronan B C
authors.initials: RB
authors.lastname: Treacy
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000379:methods*; D015331:Cohort Studies; D005260:Female; D005271:Femur Head Necrosis / Q000000981:diagnostic imaging / Q000601:surgery*; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D011859:Radiography; D012086:Reoperation; D012189:Retrospective Studies; D016896:Treatment Outcome