title: Gait Characteristics, Symptoms, and Function in Persons With Hip Osteoarthritis: A Longitudinal Study With 6 to 7 Years of Follow-up.
abstract: METHODS
  Longitudinal laboratory study.
  
  
  OBJECTIVE
  (1) To compare gait characteristics between individuals with early-stage hip osteoarthritis who underwent total hip replacement (THR) and those who did not undergo THR, and (2) to evaluate whether gait characteristics, function, and symptoms declined among individuals who did not undergo THR during a 6- to 7-year follow-up.
  
  
  BACKGROUND
  The natural history of symptoms, function, and gait changes secondary to hip osteoarthritis, including potential differences at an early stage of disease, is unknown.
  
  
  METHODS
  Forty-three individuals (mean age, 58.9 years) with radiographic and symptomatic hip osteoarthritis participated. Outcome measures included 3-D gait analysis; self-reported pain, stiffness, and function; hip range of motion; and the six-minute walk test. Baseline comparisons between individuals who later underwent THR and those who did not undergo THR were made using independent t tests or Mann-Whitney U tests. Comparisons of baseline measures and 6- to 7-year follow-up for the nonoperated individuals were conducted with paired-samples t tests or Wilcoxon signed-rank tests (P<.05).
  
  
  RESULTS
  Twelve (27.9%) of the 43 individuals initially evaluated had not undergone THR at the 6- to 7-year follow-up. At baseline, these individuals had larger sagittal plane hip and knee joint excursions, larger joint space width, lower body mass index, and superior self-reported function compared with the individuals who later underwent THR. At the 6- to 7-year follow-up, the individuals who did not undergo THR exhibited no decline in gait characteristics, minimum joint space, or overall function. Furthermore, their self-reported pain had significantly decreased (P = .024).
  
  
  CONCLUSIONS
  Individuals who did not undergo THR during a 6- to 7-year follow-up period did not exhibit a decline in gait, function, or symptoms compared to those who underwent THR. These findings are suggestive of a phenotype of hip osteoarthritis with a very slow disease progression, particularly in regard to pain.
  
  
  METHODS
  Prognosis, level 1b.
authors.affiliation: Norwegian Research Centre for Active Rehabilitation, Oslo, Norway.
authors.forename: Ingrid
authors.initials: I
authors.lastname: Eitzen
authors.forename: Linda
authors.initials: L
authors.lastname: Fernandes
authors.forename: Heidi
authors.initials: H
authors.lastname: Kallerud
authors.forename: Lars
authors.initials: L
authors.lastname: Nordsletten
authors.forename: Brian
authors.initials: B
authors.lastname: Knarr
authors.forename: May Arna
authors.initials: MA
authors.lastname: Risberg
mesh_terms: D000368:Aged; D019644:Arthroplasty, Replacement, Hip; D005260:Female; D005500:Follow-Up Studies; D005684:Gait; D006621:Hip Joint / Q000503:physiopathology*; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000503:physiopathology* / Q000601:surgery
keywords: biomechanics; joint deterioration; motion analysis; nonoperative natural history