title: Higher failure rate and stem migration of an uncemented femoral component in patients with femoral head osteonecrosis than in patients with osteoarthrosis.
abstract: BACKGROUND
  Several authors have found poorer outcome after hip replacement for osteonecrosis than after hip replacement for arthrosis. In a retrospective study we evaluated the performance of an uncemented femoral component in patients with osteonecrosis and arthrosis of the hip.
  
  
  METHODS
  31 patients operated for osteonecrosis, and 49 patients operated for osteoarthrosis were included. The median follow-up time was 6.1 (2-11) years for the patients with osteonecrosis, and 5.9 (4-8) for the arthrosis patients.
  
  
  RESULTS
  Migration analysis performed by the Einzel-Bild-Roentgen Analysis (EBRA) technique revealed a median stem migration of 1.5 (-8.8-0) mm in the patients with osteonecrosis, but only 0.6 (-2.8-0.7) mm in the patients with arthrosis (p < 0.001). Survivorship analysis with stem revision as endpoint for failure was 74% (95% CI: 55-94) in the osteonecrosis, and 98% (95% CI: 94-100) in the arthrosis group (p = 0.01).
  
  
  CONCLUSIONS
  We suggest that the higher failure rate and stem migration of uncemented total hip replacement in the patients with osteonecrosis is a consequence of the disease. On the basis of these findings, we recommend close monitoring of the patients with osteonecrosis, which should include migration measurements.
authors.affiliation: Department of Orthopaedic Surgery, University School of Medicine, AT-8036 Graz, Austria. roman.radl@meduni-graz.at
authors.forename: Roman
authors.initials: R
authors.lastname: Radl
authors.forename: Marc
authors.initials: M
authors.lastname: Hungerford
authors.forename: Wilfried
authors.initials: W
authors.lastname: Materna
authors.forename: Peter
authors.initials: P
authors.lastname: Rehak
authors.forename: Reinhard
authors.initials: R
authors.lastname: Windhager
mesh_terms: D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects / Q000379:methods; D005260:Female; D005271:Femur Head Necrosis / Q000601:surgery*; D005500:Follow-Up Studies; D006622:Hip Prosthesis / Q000592:standards; D006801:Humans; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000601:surgery*; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012189:Retrospective Studies; D016896:Treatment Outcome