title: No difference in gait recovery after THA with different head diameters: a prospective randomized study.
abstract: BACKGROUND
  Larger femoral heads are commonly presumed to improve joint stability and hip biomechanics; some studies have suggested they may hasten recovery of a normal gait. To our knowledge, no gait analysis studies have compared different size head diameters in THA.
  
  
  OBJECTIVE
  We compared (1) spatiotemporal gait parameters, (2) kinematic and kinetic gait parameters, and (3) Harris hip scores in patients undergoing THA randomized to receive a 28-, 36-, or ≥ 42-mm bearing couple. We hypothesized a larger femoral head would restore an earlier, more physiologic gait pattern.
  
  
  METHODS
  This randomized, blinded study involved 60 patients who received the same cementless THA except for the size of the bearing. Inclusion criteria were primary hip arthritis, female sex, and age between 55 and 70 years. Exclusion criteria were other problems influencing walking ability. The patients were randomized into three groups of 20 each (28- and 36-mm ceramic-on-crosslinked polyethylene, ≥ 42-mm metal-on-metal). All patients underwent the same postoperative rehabilitation protocol. Gait evaluation using an optoelectronic system was performed preoperatively and at 2 and 4 months postoperatively.
  
  
  RESULTS
  With the numbers available, no differences in spatiotemporal gait parameters, kinematic or kinetic gait parameters, or Harris hip scores emerged among the three groups. All variables assessed at 4 months postoperatively showed improvements across all groups, but the differences among them were not significant.
  
  
  CONCLUSIONS
  The hypothesis that a larger femoral head results in improved early gait performance was not supported by this study.
authors: Hip Department, IRCCS Istituto Ortopedico Galeazzi, via R. Galeazzi 4, 20161, Milan, Italy.
authors: Luigi
authors: L
authors: Zagra
authors: Federica
authors: F
authors: Anasetti
authors: Luca
authors: L
authors: Bianchi
authors: Vittorio
authors: V
authors: Licari
authors: Roberto
authors: R
authors: Giacometti Ceroni
mesh_terms: D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation* / Q000379:methods; D001696:Biomechanical Phenomena / Q000502:physiology; D004311:Double-Blind Method; D005260:Female; D005270:Femur Head / Q000503:physiopathology / Q000601:surgery; D005684:Gait / Q000502:physiology*; D006621:Hip Joint / Q000503:physiopathology / Q000601:surgery; D006622:Hip Prosthesis; D006801:Humans; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology; D015207:Osteoarthritis, Hip / Q000503:physiopathology / Q000601:surgery*; D016059:Range of Motion, Articular / Q000502:physiology*; D020127:Recovery of Function / Q000502:physiology*; D016896:Treatment Outcome
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