title: The efficacy of modified direct lateral versus posterior approach on gait function and hip muscle strength after primary total hip arthroplasty at 12months follow-up. An explorative randomised controlled trial.
abstract: The lateral and the posterior approach are the most commonly used procedures for total hip arthroplasty. Due to the detachment of the hip abductors, lateral approach is claimed to cause reduced hip muscle strength and altered gait pattern. However, this has not been investigated in a randomised controlled trial. The aim was to compare the efficacy of total hip arthroplasty performed by lateral or posterior approach on gait function and hip muscle strength up to 12months post-operatively. We hypothesised that posterior approach would be superior to lateral approach.
  
  
  
  Forty-seven patients with primary hip osteoarthritis were randomised to total hip arthroplasty with either posterior or lateral approach and evaluated pre-operatively, 3 and 12months post-operatively using 3-dimensional gait analyses as objective measures of gait function, including Gait Deviation Index, temporo-spatial parameters and range of motion. Isometric maximal hip muscle strength in abduction, flexion and extension was also tested.
  
  
  
  Post-operatively, no between-group difference in gait function was observed. However, both hip abductor and flexor muscle strength improved more in the posterior approach group: -0.20(Nm/kg)[95%CI:-0.4 to 0.0] and -0.20(Nm/kg)[95%CI:-0.4 to 0.0], respectively.
  
  
  
  Contrary to our first hypothesis, the overall gait function in the posterior approach group did not improve more than in the lateral approach group. However, in agreement with our second hypothesis, patients in the posterior approach group improved more in hip abductor and flexor muscle strength at 12months. Further investigation of the effect of reduced maximal hip muscle strength on functional capacity is needed. ClinicalTrials.gov. No.: NCT01616667.
authors.affiliation: Department of Orthopaedic Surgery and Traumatology, Odense University Hospital, Institute of Clinical Research, University of Southern Denmark, Sdr. Boulevard 29, DK-5000 Odense C, Denmark; Department of Orthopaedic Surgery and Traumatology, Zealand University Hospital, Lykkebækvej 1, DK-4600 Køge, Denmark. Electronic address: signe.rosenlund@gmail.com.
authors.forename: Signe
authors.initials: S
authors.lastname: Rosenlund
authors.affiliation: Department of Orthopaedic Surgery and Traumatology, Zealand University Hospital, Lykkebækvej 1, DK-4600 Køge, Denmark. Electronic address: lbre@regionsjaelland.dk.
authors.forename: Leif
authors.initials: L
authors.lastname: Broeng
authors.affiliation: Department of Orthopaedic Surgery and Traumatology, Odense University Hospital, Institute of Clinical Research, University of Southern Denmark, Sdr. Boulevard 29, DK-5000 Odense C, Denmark. Electronic address: soeren.overgaard@rsyd.dk.
authors.forename: Søren
authors.initials: S
authors.lastname: Overgaard
authors.affiliation: Department of Orthopaedic Surgery and Traumatology, Odense University Hospital, Institute of Clinical Research, University of Southern Denmark, Sdr. Boulevard 29, DK-5000 Odense C, Denmark. Electronic address: cjensen@health.sdu.dk.
authors.forename: Carsten
authors.initials: C
authors.lastname: Jensen
authors.affiliation: Department of Orthopaedic Surgery and Traumatology, Odense University Hospital, Institute of Clinical Research, University of Southern Denmark, Sdr. Boulevard 29, DK-5000 Odense C, Denmark. Electronic address: ahlarsen@health.sdu.dk.
authors.forename: Anders
authors.initials: A
authors.lastname: Holsgaard-Larsen
mesh_terms: D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D005684:Gait / Q000502:physiology*; D006615:Hip / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000503:physiopathology; D015207:Osteoarthritis, Hip / Q000503:physiopathology / Q000601:surgery; D016059:Range of Motion, Articular; D016896:Treatment Outcome
keywords: Gait function; Hip muscle strength; Osteoarthritis; Total hip arthroplasty