title: Revision hip preservation surgery with hip arthroscopy: clinical outcomes.
abstract: OBJECTIVE
  To analyze and report the clinical outcomes of a cohort of patients who underwent revision hip preservation with arthroscopy and determine predictors of positive and negative outcomes.
  
  
  METHODS
  During the study period from April 2008 to December 2010, all patients who underwent revision hip preservation with arthroscopy were included. This included patients who had previous open surgery and underwent revision with arthroscopy. Patient-reported outcome (PRO) scores were obtained preoperatively and at 3-month, 1-year, 2-year, and 3-year follow-up time points. Any revision surgeries and conversions to total hip arthroplasty were noted. A multiple regression analysis was performed to look for positive and negative predictive factors for improvement in PROs after revision hip arthroscopy.
  
  
  RESULTS
  Forty-seven hips in 43 patients had completed 2 years' follow-up or needed total hip arthroplasty. The mean length of follow-up was 29 months (range, 24 to 47 months). Of the hips, 31 (66%) had either unaddressed or incompletely treated femoroacetabular impingement. There was a significant improvement in all PRO scores at a mean of 29 months after revision (P < .0001). The visual analog scale score improved from 7.3 ± 1.5 to 3.9 ± 2.5 (P < .0001). Improvements in the Non-Arthritic Hip Score of at least 10 points and 20 points were found in 28 hips (65%) and 19 hips (44%), respectively. Four hips in 3 patients required conversion to total hip arthroplasty. Positive predictive factors for PRO improvement were previous open surgery, pincer impingement, cam impingement, symptomatic heterotopic ossification, and segmental labral defects treated with labral reconstruction.
  
  
  CONCLUSIONS
  On the basis of multiple PROs, revision hip preservation with hip arthroscopy can achieve moderately successful outcomes and remains a viable treatment strategy after failed primary hip preservation surgery. Preoperative predictors of success after revision hip arthroscopy include segmental labral defects, unaddressed or incompletely addressed femoroacetabular impingement, heterotopic ossification, and previous open surgery.
  
  
  METHODS
  Level IV, therapeutic case series.
authors.affiliation: American Hip Institute, Chicago, Illinois, U.S.A; Loyola University Stritch School of Medicine, Chicago, Illinois, U.S.A. Electronic address: DrDomb@americanhipinstitute.org.
authors.forename: Benjamin G
authors.initials: BG
authors.lastname: Domb
authors.affiliation: American Hip Institute, Chicago, Illinois, U.S.A.
authors.forename: Christine E
authors.initials: CE
authors.lastname: Stake
authors.affiliation: American Hip Institute, Chicago, Illinois, U.S.A.
authors.forename: Dror
authors.initials: D
authors.lastname: Lindner
authors.affiliation: American Hip Institute, Chicago, Illinois, U.S.A.
authors.forename: Youseff
authors.initials: Y
authors.lastname: El-Bitar
authors.affiliation: American Hip Institute, Chicago, Illinois, U.S.A; Congress Medical Associates, Pasadena, California, U.S.A.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Jackson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D018771:Arthralgia / Q000209:etiology / Q000517:prevention & control*; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects*; D001182:Arthroscopy; D015331:Cohort Studies; D005260:Female; D057925:Femoracetabular Impingement / Q000209:etiology / Q000601:surgery*; D005500:Follow-Up Studies; D006801:Humans; D007593:Joint Instability / Q000209:etiology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D012044:Regression Analysis; D012086:Reoperation; D016896:Treatment Outcome; D055815:Young Adult