title: Value of computed tomography-based three-dimensional surgical preoperative planning software in total hip arthroplasty with developmental dysplasia of the hip.
abstract: BACKGROUND
  Preoperative planning with computed tomography (CT)-based three-dimensional templating has been expanded to achieve more precise placement of hip components. However, few reports have addressed the utility of three-dimensional surgical planning software for secondary osteoarthritis cases. This study therefore investigated the value of CT-based three-dimensional templating software for preoperative planning in primary total hip arthroplasty (THA), with an emphasis on developmental dysplasia of the hip.
  
  
  METHODS
  We performed a retrospective review of 65 hips in 57 patients who underwent cementless primary THA. The preoperative diagnosis was secondary osteoarthritis in all cases due to developmental dysplasia of the hip. All preoperative planning and postoperative evaluations were completed using CT-based three-dimensional templating software. We analyzed the accuracy of stem size prediction and cup size prediction, the reproducibility of preoperative and postoperative stem anteversion, and the absolute error in preoperative and postoperative stem anteversion using CT-based three-dimensional templating software.
  
  
  RESULTS
  The sizes of 65 % of the femoral stems (42/65) were estimated exactly, and 98 % (63/65) were accurately estimated to within one stem size. The final acetabular cup sizes corresponded exactly to the preoperatively planned size in 92 % of all cases (62/65). 100 % of the cup size estimates were accurate to within one cup size. There was strong reproducibility of preoperative and postoperative stem anteversion (r = 0.88, P < 0.05). The absolute error in stem anteversion was 4.0° ± 3.6°.
  
  
  CONCLUSIONS
  Using CT-based three-dimensional templating software made it possible to achieve reproducible stem anteversion and choose accurate stem and cup sizes in patients with developmental dysplasia of the hip.
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medical Science, Kanazawa University, 13-1 Takaramachi, Kanazawa, Ishikawa, 920-8641, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Inoue
authors.forename: Tamon
authors.initials: T
authors.lastname: Kabata
authors.forename: Toru
authors.initials: T
authors.lastname: Maeda
authors.forename: Yoshitomo
authors.initials: Y
authors.lastname: Kajino
authors.forename: Kenji
authors.initials: K
authors.lastname: Fujita
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Hasegawa
authors.forename: Takashi
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Tsuchiya
mesh_terms: D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip; D001848:Bone Diseases, Developmental / Q000000981:diagnostic imaging* / Q000601:surgery*; D005260:Female; D006621:Hip Joint / Q000000981:diagnostic imaging* / Q000601:surgery*; D006622:Hip Prosthesis; D006801:Humans; D021621:Imaging, Three-Dimensional; D007592:Joint Diseases / Q000000981:diagnostic imaging* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011300:Preoperative Care; D017755:Prosthesis Fitting; D012189:Retrospective Studies; D012984:Software; D014057:Tomography, X-Ray Computed