title: Hip resurfacing for osteonecrosis: two- to 18-year results of the Conserve Plus design and technique.
abstract: OBJECTIVE
  Hip resurfacing arthroplasty (HRA) is an alternative to conventional total hip arthroplasty for patients with osteonecrosis (ON) of the femoral head. Our aim was to report the long-term outcome of HRA, which is not currently known.
  
  
  METHODS
  Long-term survivorship, clinical scores and radiographic results for 82 patients (99 hips) treated with HRA for ON over a period of 18 years were reviewed retrospectively. The mean age of the 67 men and 15 women at the time of surgery was 40.8 years (14 to 64). Patients were resurfaced regardless of the size of the osteonecrotic lesion.
  
  
  RESULTS
  The mean clinical follow-up was 10.8 years (2 to 18). The mean University of California, Los Angeles hip scores at the last follow-up were 9.3, 9.4, 9.2 and 6.8 for pain, walking, function and activity, respectively. A total of six hips underwent revision surgery, four for loosening of the femoral component and two for loosening of the acetabular component. Using any revision as an end point, the 15-year Kaplan-Meier survivorship was 90.3%. There were no wear-related failures. There were no femoral failures among the hips reconstructed with a cemented metaphyseal stem. A total of five hips showed narrowing of the femoral neck; all stabilised and remain asymptomatic, 21 showed signs of femoral neck impingement.
  
  
  CONCLUSIONS
  To our knowledge, this is the first report of a series of HRA performed for ON with 15-year survivorship. Our data confirm that patients with advanced stages of ON of the femoral head are excellent candidates for HRA. Cite this article: Bone Joint J 2016;98-B:901-9.
authors.affiliation: Joint Replacement Institute at St Vincent Medical Center, Los Angeles, 2200 West Third Street, Suite 400, Los Angeles, CA, 90057, USA.
authors.forename: H C
authors.initials: HC
authors.lastname: Amstutz
authors.affiliation: Joint Replacement Institute at St Vincent Medical Center, Los Angeles, 2200 West Third Street, Suite 400, Los Angeles, CA, 90057, USA.
authors.forename: M J
authors.initials: MJ
authors.lastname: Le Duff
mesh_terms: D000293:Adolescent; D000328:Adult; D019644:Arthroplasty, Replacement, Hip / Q000379:methods*; D002857:Chromium; D003035:Cobalt; D003646:Debridement; D005260:Female; D005271:Femur Head Necrosis / Q000145:classification / Q000000981:diagnostic imaging / Q000601:surgery*; D005500:Follow-Up Studies; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D061825:Metal-on-Metal Joint Prostheses; D008875:Middle Aged; D011474:Prosthesis Design; D012086:Reoperation; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D002857:Chromium; D003035:Cobalt
keywords: Osteonecrosis Hip Resurfacing