title: Influence of hip replacement on sagittal alignment of the lumbar spine: An EOS study.
abstract: BACKGROUND
  Changes in pelvic position can influence the sagittal alignment of the lumbar spine. The restoration of hip kinematics by hip replacement thus appears to offer the possibility of correcting sagittal alignment. This preliminary retrospective study used EOS imaging to investigate the influence of total hip arthroplasty on pelvic parameters in patients with normal preoperative pelvic parameters.
  
  
  METHODS
  Twenty patients with hip osteoarthritis undergoing total hip arthroplasty (THA) between 2011 and 2012 received unilateral THA. To evaluate the preoperative and postoperative changes of the pelvic parameters, we analyzed EOS imaging of the patients to determine pelvic incidence, sacral slope, sacral tilt, pelvic tilt, anterior pelvic plane inclination and pelvic axial rotation. Additionally, anteversion and inclination of the acetabular cup position were determined.
  
  
  RESULTS
  No statistically significant difference was found between the preoperative and postoperative measurements of pelvic parameters, although the change in pelvic tilt approached significance. Postoperatively, respective average values of 42.6° and 22.7° were measured for inclination and anteversion of the acetabular cup position.
  
  
  CONCLUSIONS
  THA did not influence pelvic position and sagittal alignment in patients with normal preoperative pelvic parameters. A subsequent study will investigate whether corrections of pelvic parameters outside the norm in patients with OA are possible with THA.
authors.affiliation: Department of Orthopedics and Trauma Surgery, University Hospital of Cologne, Cologne, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Bredow
authors.affiliation: Department of Orthopedics and Trauma Surgery, University Hospital of Cologne, Cologne, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Katinakis
authors.affiliation: Department of Orthopedics, St. Franziskus Hospital, Cologne, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Schlüter-Brust
authors.affiliation: Department of Radiology, University Hospital of Cologne, Cologne, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Krug
authors.affiliation: Department of Neurophysiology, Center of Biomedicine and Medical Technology Mannheim, Ruprecht-Karls-University Heidelberg, Mannheim, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Pfau
authors.affiliation: Department of Orthopedics and Trauma Surgery, University Hospital of Cologne, Cologne, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Eysel
authors.affiliation: Department of Orthopedics and Trauma Surgery, University Hospital of Cologne, Cologne, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Dargel
authors.affiliation: Department of Orthopedics and Trauma Surgery, University Hospital of Cologne, Cologne, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Wegmann
mesh_terms: D000077:Acetabulum / Q000033:anatomy & histology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000033:anatomy & histology*; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000601:surgery; D011187:Posture; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000295:instrumentation*; D012189:Retrospective Studies
keywords: Sagittal alignment; hip osteoarthritis; lumbar spine; pelvic parameters; total hip arthroplasty