title: Preoperative prediction of ambulatory status at 6 months after total hip arthroplasty.
abstract: BACKGROUND
  Total hip arthroplasty (THA) is an effective procedure that provides patients with long-term relief from pain and enables them to resume their normal daily activities. Preoperative instruction about the functional outcomes and optimum goal of rehabilitation is helpful for patients undergoing THA.
  
  
  OBJECTIVE
  The purposes of this study were: (1) to examine the relationships between preoperative physical functions and ambulation following THA and (2) to identify optimal cutoff values for estimating ambulatory status at 6 months after THA.
  
  
  METHODS
  This was a retrospective study.
  
  
  METHODS
  The study participants were 204 patients who underwent a unilateral THA. Hip abductor and knee extensor strength were measured and the Timed "Up & Go" Test (TUG) was conducted preoperatively. The patients were divided into 2 groups according to self-reported walking ability at 6 months postoperatively: an independent ambulation group (n=118) and a cane-assisted ambulation group (n=86). Differences between the 2 groups were examined using an unpaired t test or the chi-square test. A stepwise multiple logistic regression analysis was performed with walking ability at 6 months postoperatively as a dependent variable and age, sex, contralateral hip osteoarthritis (ie, whether a participant had contralateral hip osteoarthritis or not), body mass index, hip abductor strength, knee extensor strength, and TUG score as independent variables. Receiver operating characteristic curve analysis was used to identify a cutoff point for classifying the participants into the 2 groups.
  
  
  RESULTS
  A stepwise multiple logistic regression analysis selected 3 factors (age, knee extensor strength, and TUG score) as significant variables affecting the midterm ambulatory ability after THA. Moreover, receiver operating characteristic curve analyses revealed that the midterm (ie, 6-month) ambulatory status after THA was more accurately predicted by the patient's TUG score (cutoff point=10 seconds, sensitivity=76.7%, specificity=93.2%, area under the curve=0.93) than by age and knee extensor strength.
  
  
  CONCLUSIONS
  The categorization of ambulatory status in this study was based solely on self-reported walking ability.
  
  
  CONCLUSIONS
  The findings indicate that patients with a preoperative TUG score of less than 10 seconds are likely to walk without an assistive device at 6 months after THA.
authors.affiliation: Rehabilitation Unit, Kyoto University Hospital, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan. nankaku@kuhp.kyoto-u.ac.jp
authors.forename: Manabu
authors.initials: M
authors.lastname: Nankaku
authors.forename: Tadao
authors.initials: T
authors.lastname: Tsuboyama
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Akiyama
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Kakinoki
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Fujita
authors.forename: Jun
authors.initials: J
authors.lastname: Nishimura
authors.forename: Yuji
authors.initials: Y
authors.lastname: Yoshioka
authors.forename: Haruna
authors.initials: H
authors.lastname: Kawai
authors.forename: Shuichi
authors.initials: S
authors.lastname: Matsuda
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D019644:Arthroplasty, Replacement, Hip / Q000534:rehabilitation*; D002081:Buttocks; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000503:physiopathology; D011237:Predictive Value of Tests; D057234:Preoperative Period; D012372:ROC Curve; D012189:Retrospective Studies; D057566:Self Report; D013647:Task Performance and Analysis; D013848:Thigh; D013997:Time Factors; D016138:Walking / Q000502:physiology*