title: Relationship between Wiberg's lateral center edge angle, Lequesne's acetabular index, and medial acetabular bone stock.
abstract: OBJECTIVE
  Knowledge of acetabular anatomy is crucial for cup positioning in total hip replacement. Medial wall thickness of the acetabulum is known to correlate with the degree of developmental dysplasia of the hip (DDH). No data exist about the relationship of routinely used radiographic parameters such as Wiberg's lateral center edge angle (LCE-angle) or Lequesne's acetabular index (AI) with thickness of the medial acetabular wall in the general population. The aim of our study was to clarify the relationship between LCE, AI, and thickness of the medial acetabular wall.
  
  
  METHODS
  Measurements on plain radiographs (LCE and AI) and axial CT scans (quadrilateral plate acetabular distance QPAD) of 1,201 individuals (2,402 hips) were obtained using a PACS imaging program and statistical analyses were performed.
  
  
  RESULTS
  The mean thickness of the medial acetabulum bone stock (QPAD) was 1.08 mm (95% CI: 1.05-1.10) with a range of 0.1 to 8.8 mm. For pathological values of either the LCE (<20°) or the AI (>12°) the medial acetabular wall showed to be thicker than in radiological normal hips. The overall correlation between coxometric indices and medial acetabular was weak for LCE (r =-0.21. 95% CI [-0.25, -0.17]) and moderate for AI (r = 0.37, [0.33, 0.41]).
  
  
  CONCLUSIONS
  We did not find a linear relationship between Wiberg's lateral center edge angle, Lequesne's acetabular index and medial acetabular bone stock in radiological normal hips but medial acetabular wall thickness increases with dysplastic indices.
authors.affiliation: Department of Orthopaedics, Balgrist University Hospital Zurich, Zurich, Switzerland. clement.werner@usz.ch
authors.forename: Clément M L
authors.initials: CM
authors.lastname: Werner
authors.forename: Carol E
authors.initials: CE
authors.lastname: Copeland
authors.forename: Thomas
authors.initials: T
authors.lastname: Ruckstuhl
authors.forename: Jeff
authors.initials: J
authors.lastname: Stromberg
authors.forename: Clifford H
authors.initials: CH
authors.lastname: Turen
authors.forename: Samy
authors.initials: S
authors.lastname: Bouaicha
mesh_terms: D000077:Acetabulum / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010384:Pelvic Bones / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed; D055815:Young Adult