title: The Accuracy of Acetabular Component Position Using a Novel Method to Determine Anteversion.
abstract: This study compares the differences in acetabular component position, leg length discrepancy, and hip offset between the anterior and posterior approach. A novel method is applied to determine the acetabular anteversion using the C-arm tilt angle for the anterior approach.
  
  
  
  Hundred consecutive anterior total hip arthroplasties were matched according to gender, body mass index, and age to a cohort of 100 primary total hip arthroplasties operated on through a posterior approach. Postoperative radiographs were analyzed to determine cup inclination, cup anteversion, leg length discrepancy, and hip offset.
  
  
  
  The mean inclination was 40.8° (range 33°-48°) and 45.1° (range 33°-55°) for the anterior and posterior approach, respectively. Using the new C-arm tilt plane technique, an average acetabular anteversion of 18.4° (range 11°-26°) was achieved with the anterior approach compared with 23.6° (range 8°-38°) with the posterior approach. Hundred percent cups in the anterior group and 81% in the posterior group fell within the safe zone (P < .001). There was no difference in the overall hip offset between the operated side and the contralateral side for the anterior (P = .074) and posterior (P = .919) group. There was no difference in leg length discrepancy between the 2 approaches (P = .259).
  
  
  
  Intraoperative fluoroscopy-assisted direct anterior approach was associated with improved acetabular component positioning. However, no benefit was shown with regards to restoration of hip offset or leg length.
authors.affiliation: Adult Reconstruction & Joint Replacement Division, Hospital for Special Surgery, New York, New York.
authors.forename: Friedrich
authors.initials: F
authors.lastname: Boettner
authors.affiliation: Division of Orthopaedics and Trauma Surgery, Geneva University Hospitals, Genève 14, Switzerland.
authors.forename: Matthieu
authors.initials: M
authors.lastname: Zingg
authors.affiliation: Adult Reconstruction & Joint Replacement Division, Hospital for Special Surgery, New York, New York.
authors.forename: Ahmed K
authors.initials: AK
authors.lastname: Emara
authors.affiliation: Department of Orthopedics, Vienna General Hospital, Medical University of Vienna, Vienna, Austria.
authors.forename: Wenzel
authors.initials: W
authors.lastname: Waldstein
authors.affiliation: Department of Orthopedic Surgery, University of Ulm, Ulm, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Faschingbauer
authors.affiliation: Adult Reconstruction & Joint Replacement Division, Hospital for Special Surgery, New York, New York.
authors.forename: Maximilian F
authors.initials: MF
authors.lastname: Kasparek
mesh_terms: D000077:Acetabulum / Q000000981:diagnostic imaging / Q000601:surgery*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000379:methods* / Q000706:statistics & numerical data; D005260:Female; D005471:Fluoroscopy / Q000379:methods; D006622:Hip Prosthesis; D006801:Humans; D007870:Leg Length Inequality / Q000601:surgery; D008297:Male; D008875:Middle Aged; D056888:Patient Positioning; D011184:Postoperative Period; D011859:Radiography; D012189:Retrospective Studies
keywords: acetabular component; anterior approach; cup position; intraoperative fluoroscopy; total hip arthroplasty