title: Eccentric rotational acetabular osteotomy for acetabular dysplasia: follow-up of one hundred and thirty-two hips for five to ten years.
abstract: BACKGROUND
  Eccentric rotational acetabular osteotomy for the operative treatment of acetabular dysplasia consists of a spherical but eccentric osteotomy and rotation of the acetabulum that moves the center of rotation of the head of the femur medially and distally. No bone graft is needed. The reorientation of the acetabular fragment not only improves acetabular coverage but also restores the center of rotation of the subluxated hip. The purpose of this paper was to describe eccentric rotational acetabular osteotomy for the treatment of acetabular dysplasia and to evaluate its clinical and radiographic outcomes.
  
  
  METHODS
  We performed this procedure consecutively in 132 hips in 126 patients with dysplasia of the hip. Eighteen hips had no osteoarthritis, fifty-three had early osteoarthritis, and sixty-one had advanced osteoarthritis. Seven patients were male, and 119 were female. The average age was 36.5 years at the time of the index operation, and the average duration of follow-up was 7.5 years. Twenty-three hips in twenty-two patients were also treated with intertrochanteric valgus osteotomy to further improve joint congruency at the time of the acetabular osteotomy.
  
  
  RESULTS
  The average preoperative Harris hip score of 71 points improved to an average score of 89 points at the time of the latest follow-up. The average center-edge angle improved from 0  to 36 . An apparent change in the stage of the arthritis was observed in seven hips (5%), one of which had had early-stage disease and six of which had had advanced disease preoperatively.
  
  
  CONCLUSIONS
  Eccentric rotational acetabular osteotomy appears to be a good treatment option for young patients with either early or advanced hip osteoarthritis secondary to dysplasia.
authors.affiliation: Department of Orthopaedics, Nagoya University School of Medicine, Nagoya, Japan. hassey@med.nagoya-u.ac.jp
authors.forename: Yukiharu
authors.initials: Y
authors.lastname: Hasegawa
authors.forename: Toshiki
authors.initials: T
authors.lastname: Iwase
authors.forename: Shinji
authors.initials: S
authors.lastname: Kitamura
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Yamauchi Ki
authors.forename: Shinji
authors.initials: S
authors.lastname: Sakano
authors.forename: Hisashi
authors.initials: H
authors.lastname: Iwata
mesh_terms: D000077:Acetabulum / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery*; D000328:Adult; D001848:Bone Diseases, Developmental / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006621:Hip Joint / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery*; D010027:Osteotomy; D011859:Radiography; D020127:Recovery of Function / Q000502:physiology; D012399:Rotation; D013997:Time Factors; D016896:Treatment Outcome