title: Use of metal-on-metal total hip resurfacing for the treatment of osteonecrosis of the femoral head.
abstract: BACKGROUND
  Recently, with the advent of improved metal-on-metal prostheses, total hip resurfacing has emerged as a viable arthroplasty option. However, it remains controversial whether this procedure should be used in patients with osteonecrosis when the femoral resurfacing component is cemented onto dead bone. The purpose of this study was to analyze the clinical and radiographic outcomes of metal-on-metal total hip resurfacing arthroplasty in patients with osteonecrosis of the femoral head. In addition, this group was compared with a matched group of patients who were diagnosed as having osteoarthritis.
  
  
  METHODS
  Forty-two osteonecrotic hips that were treated with a metal-on-metal total hip resurfacing arthroplasty were studied. They were matched by gender, age, prosthesis, surgeon, and surgical approach to forty-two osteoarthritic hips that were treated with the same metal-on-metal prosthesis. In the osteonecrosis group, there were twenty-five men and eleven women, and in the osteoarthritis group, there were twenty-eight men and thirteen women. The mean age at the time of surgery was forty-two years. Patients were followed both clinically and radiographically for a mean of forty-one months.
  
  
  RESULTS
  The clinical outcomes were similar for both groups, with a good or excellent outcome in thirty-nine hips (93%) with osteonecrosis and a good or excellent outcome in forty-one hips (98%) with osteoarthritis. In each of the two groups, there were two failures that required conversion to a standard total hip arthroplasty. Survivorship curves were similar for the two patient groups.
  
  
  CONCLUSIONS
  The short-term results for metal-on-metal total hip resurfacing for this challenging patient population with osteonecrosis were excellent and comparable with those seen in patients with osteoarthritis. We await long-term results to see if these early results are maintained.
  
  
  METHODS
  Prognostic Level II. See Instructions to Authors on jbjs.org for a complete description of levels of evidence.
authors.affiliation: Center for Joint Preservation and Reconstruction, Rubin Institute for Advanced Orthopedics, Sinai Hospital of Baltimore, 2401 West Belvedere Avenue, Baltimore, MD 21215, USA. Rhondamont@aol.com
authors.forename: Michael A
authors.initials: MA
authors.lastname: Mont
authors.forename: Thorsten M
authors.initials: TM
authors.lastname: Seyler
authors.forename: David R
authors.initials: DR
authors.lastname: Marker
authors.forename: German A
authors.initials: GA
authors.lastname: Marulanda
authors.forename: Ronald E
authors.initials: RE
authors.lastname: Delanois
mesh_terms: D000293:Adolescent; D000328:Adult; D019644:Arthroplasty, Replacement, Hip / Q000379:methods*; D005260:Female; D005271:Femur Head Necrosis / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D005500:Follow-Up Studies; D006622:Hip Prosthesis; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D011859:Radiography; D016059:Range of Motion, Articular / Q000502:physiology; D020127:Recovery of Function / Q000502:physiology; D012189:Retrospective Studies