title: True or apparent leg length discrepancy: which is a better predictor of short-term functional outcomes after total hip arthroplasty?
abstract: OBJECTIVE
  The associations between leg length discrepancy (LLD) and patient-perceived inequality and functional outcomes after total hip arthroplasty (THA) are unclear in the literature. The aim of this study was to determine the types of LLD after THA and to identify the best predictor of patient-perceived LLD and functional outcome in the short term after THA.
  
  
  METHODS
  We subdivided LLD into true and apparent types and prospectively studied 53 consecutive patients undergoing unilateral primary THA to determine whether there is an association between the type of LLD and functional outcome 2 months after the operation. Apparent LLD was measured by the block test and true LLD was measured by hip radiography. We classified the patients into 4 groups: true, apparent, mixed, and no-LLD groups. The questionnaire included a visual analog scale of pain, the Western Ontario and McMaster Universities Osteoarthritis Index, and patient-perceived inequality. Physical performance was measured using walking speed and the Timed Up and Go test.
  
  
  RESULTS
  The apparent and mixed LLD groups had a higher prevalence of patient-perceived inequality than the true and no-LLD groups. The results of physical performance showed that the walking speed of the mixed LLD group and the results of the Timed Up and Go Test of the apparent LLD group were significantly slower than those of the true LLD group.
  
  
  CONCLUSIONS
  We suggested that the true LLD group may have a weak relationship with functional outcome after THA while the apparent LLD resulting from pelvic obliquity due to hip contracture or scoliosis is correlated with the short-term functional outcome after THA.
  
  
  CONCLUSIONS
  Apparent LLD can be a better predictor of patient-perceived inequality and physical performance than true LLD.
authors: 1Department of Physical Medicine and Rehabilitation, Tohoku University Graduate School of Medicine, Sendai, Japan. 2Department of Physical Therapy, Tohoku Medical Care College, Sendai, Japan. 3Department of Rehabilitation, Kansai Medical University Takii Hospital, Osaka, Japan. 4Department of Rehabilitation, Okii clinic, Iwakuni, Japan. 5Department of Orthopaedic Surgery Matsuda hospital, Sendai, Japan.
authors: Tatsuya
authors: T
authors: Nakanowatari
authors: Yoshimi
authors: Y
authors: Suzukamo
authors: Toshimitsu
authors: T
authors: Suga
authors: Akira
authors: A
authors: Okii
authors: Genji
authors: G
authors: Fujii
authors: Shin-Ichi
authors: S
authors: Izumi
mesh_terms: D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects* / Q000523:psychology*; D005260:Female; D006801:Humans; D007866:Leg / Q000033:anatomy & histology / Q000502:physiology; D007870:Leg Length Inequality / Q000453:epidemiology / Q000503:physiopathology* / Q000523:psychology*; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000453:epidemiology; D010465:Perception; D026741:Physical Therapy Modalities; D011446:Prospective Studies; D015203:Reproducibility of Results