title: What is the prognosis of revision total hip arthroplasty in patients 55 years and younger?
abstract: BACKGROUND
  Revision THAs are expected to increase; however, few studies have characterized the prognosis of revision THAs in younger patients.
  
  
  OBJECTIVE
  We performed a case-control study to evaluate intermediate-term survivorship, complications, and hip and activity scores after revision THAs in patients 55 years and younger, compared these outcomes with the results of primary THAs in a matched patient population, and evaluated risk factors for failed revisions.
  
  
  METHODS
  Ninety-three patients (103 hips) had a minimum of 4 years after revision THA, died, or had rerevision surgery. They were matched with 98 patients (103 hips) with primary THAs. Survivorship, complications, and clinical outcomes were compared between the groups using t-tests. Risk factors for failure also were assessed with chi-square analysis.
  
  
  RESULTS
  At mean followup of 6.7 years, 71 revision THAs (69%) survived, compared with 102 (99%) primary THAs (odds ratio [OR], 45.9; 95% CI, 16.5-128.4; p < 0.001). Complications occurred in 29% of the revision group and 6% of the primary group (OR, 6.64; 95% CI, 4.14-10.67; p < 0.001). After revision THA, the average improvement in Harris hip score was 19.2 compared with 34.4 after primary THA (p < 0.001). The UCLA activity score improved by an average of 0.87 after revision compared with 2.36 after primary THA (p < 0.001). Conventional polyethylene was associated with failure after revision THA (OR, 2.98; 95% CI, 1.87-4.76; p = 0.004).
  
  
  CONCLUSIONS
  At intermediate-term followup, young patients undergoing revision THAs had markedly higher failure and complication rates and more modest clinical improvements compared with patients in a matched cohort who had primary THAs.
  
  
  METHODS
  Level III, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.
authors.affiliation: Department of Orthopaedic Surgery, Washington University School of Medicine, 660 South Euclid Avenue, Campus Box 8233, St Louis, MO, 63110, USA, muyibat.adelani@gmail.com.
authors.forename: Muyibat A
authors.initials: MA
authors.lastname: Adelani
authors.forename: Karla
authors.initials: K
authors.lastname: Crook
authors.forename: Robert L
authors.initials: RL
authors.lastname: Barrack
authors.forename: William J
authors.initials: WJ
authors.lastname: Maloney
authors.forename: John C
authors.initials: JC
authors.lastname: Clohisy
mesh_terms: D000328:Adult; D000367:Age Factors; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects* / Q000295:instrumentation; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D005260:Female; D006621:Hip Joint / Q000503:physiopathology / Q000601:surgery*; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D015207:Osteoarthritis, Hip / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D011183:Postoperative Complications / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D011474:Prosthesis Design; D011475:Prosthesis Failure; D020127:Recovery of Function; D012042:Registries; D012086:Reoperation; D012307:Risk Factors; D013997:Time Factors; D017211:Treatment Failure; D055815:Young Adult