title: Evaluation of femoral head coverage following Chiari pelvic  osteotomy in adolescents by three-dimensional computed  tomography and conventional radiography.
abstract: BACKGROUND
  Currently, the cover of the femoral head was mainly assessed using conventional plain films after Chiari pelvic osteotomy in most studies. The purpose of the current study was to observe whether the femoral head coverage measured by three-dimensional computed tomography (3D-CT) was consistent with the radiographic findings.
  
  
  METHODS
  A total of 24 patients (24 hips) with an average age of 11.5 years, underwent Chiari osteotomy due to acetabular dysplasia, and 15 subjects (30 hips) of normal control with a mean age of 12 years were involved in the study. The pre- and postoperative coverage of femoral head was measured by using conventional plain film and 3D-CT on the anterior 1/4, middle 1/2, and posterior 1/4 coronal plane. The anterolateral, mediolateral and posterolateral coverage measured by 3D-CT were compared with the coverage measured by plain radiograph, and which were also compared with the normal control individuals.
  
  
  RESULTS
  The postoperative anterolateral, mediolateral coverage measured by 3D-CT was significantly smaller than that measured by radiography (P < 0.01). No significant difference was found between the 3D-CT measurements on the posterolateral coverage and the radiographic results. The anterolateral femoral head coverage in the patients following Chiari pelvic osteotomy was also smaller than that in the normal control individuals (P = 0.026). In contrast, the postoperative posterolateral coverage in the patients was more excessive than that in the normal control individuals (P = 0.001).
  
  
  CONCLUSIONS
  Conventional radiographs may show sufficient cover of the femoral head after Chiari osteotomy, whereas in fact, the cover may be not perfect, especially on the anterolateral part. Therefore, the postoperative 3D-CT is beneficial for evaluating the outcome of Chiari osteotomy, especially when the anterolateral coverage o
authors.affiliation: Department of Paediatric Orthopaedics, Shengjing Hospital of China Medical University, Shenyang 110004, Liaoning, China.
authors.forename: LianYong
authors.initials: L
authors.lastname: Li
authors.forename: JingYu
authors.initials: J
authors.lastname: Jia
authors.forename: Qun
authors.initials: Q
authors.lastname: Zhao
authors.forename: LiJun
authors.initials: L
authors.lastname: Zhang
authors.forename: ShiJun
authors.initials: S
authors.lastname: Ji
authors.forename: EnBo
authors.initials: E
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D002648:Child; D005260:Female; D005270:Femur Head / Q000000981:diagnostic imaging*; D006618:Hip Dislocation, Congenital / Q000532:radiotherapy / Q000601:surgery*; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D010027:Osteotomy; D010384:Pelvic Bones / Q000601:surgery*; D014057:Tomography, X-Ray Computed