title: Risk factors for revision of hip arthroplasties in patients younger than 30 years.
abstract: BACKGROUND
  Numerous reports of THAs in patients younger than 30 years indicate a high risk of revision. Although risk factors for revision have been reported for older patients, it is unclear whether these risk factors are the same as those for patients younger than 30 years.
  
  
  OBJECTIVE
  We therefore (1) determined function and survivorship of revision THAs performed in patients younger than 30 years, and (2) assessed the risk factors for revision THAs in this younger population by comparison with a group of patients younger than 30 years who did not undergo revision.
  
  
  METHODS
  We retrospectively reviewed the clinical records and radiographs of 55 patients younger than 30 years (average age at revision, 24.3 years; range, 14-30 years) who underwent 77 hip revisions. Revision was performed, on average, 4.6 years (range, 0.4-12 years) after the primary THA. The results for these 55 patients (77 revision THAs) were compared with results for a nonrevised group, including 819 THAs in patients younger than 30 years. Minimum followup of the revision group was 1 year (mean, 6.2 years; range, 1-15 years).
  
  
  RESULTS
  At followup after the revision, the Merle d'Aubigné-Postel score improved from 12.2 to 14.6. The rates of dislocation, neurologic lesions, and fractures were 15%, 7.8%, and 14%, respectively. The 10-year survival rate was 36% (95% confidence interval [CI], 21%-51%). Compared with the nonrevised group, the independent revision risk factors were young age at primary THA (OR 1.14 [1.07-1.19]), high number of previous surgeries (OR 5.41 [2.67-10.98]), and occurrence of at least one dislocation (OR 3.98 [1.74-9.07]). Hard-on-soft bearings had a higher risk (OR 3.42 [1.91-6.1]) of revision compared with hard-on-hard bearings.
  
  
  CONCLUSIONS
  Revision THAs are likely in patients younger than 30 years, and the complication rate is high. The survivorship of hip revision in this population is low and alternative solutions should be advocated whenever possible.
  
  
  METHODS
  Level III, therapeutic study, case control study. See the Guidelines for Authors for a complete description of levels of evidence.
authors.affiliation: Department of Orthopaedics, Centre Hospitalier Régional Universitaire de Lille, Roger Salengro Hospital, Lille, France. j_girard_lille@yahoo.fr
authors.forename: Julien
authors.initials: J
authors.lastname: Girard
authors.forename: Christophe
authors.initials: C
authors.lastname: Glorion
authors.forename: François
authors.initials: F
authors.lastname: Bonnomet
authors.forename: Damien
authors.initials: D
authors.lastname: Fron
authors.forename: Henri
authors.initials: H
authors.lastname: Migaud
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000704:Analysis of Variance; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects / Q000295:instrumentation*; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D005260:Female; D005602:France; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D006622:Hip Prosthesis; D006801:Humans; D053208:Kaplan-Meier Estimate; D016015:Logistic Models; D008297:Male; D015337:Multicenter Studies as Topic; D016017:Odds Ratio; D011475:Prosthesis Failure; D011859:Radiography; D012086:Reoperation; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult