title: Preoperative planning of total hip arthroplasty on dysplastic acetabuli.
abstract: BACKGROUND
  When performing total hip arthroplasty (THA) on a dysplastic hip, proper positioning of the acetabular component may not allow for more than 70% coverage. Structural support in the form of an autograft or a high porosity metal augment may be necessary. The purpose of the study was to investigate the value of preoperative templating and deformity classification in predicting cup coverage and the need for structural support.
  
  
  METHODS
  65 cases of THA for DDH were retrospectively analysed. 2 observers independently classified each dysplastic hip according to Hartofilakidis and determined the extent of cup coverage via templating software on preoperative digital AP pelvic radiographs.
  
  
  RESULTS
  Weighted kappa interobserver agreement was 0.68 for cup coverage and 0.76 for Hartofilakidis type. Structural support was necessary in 10 hips. No structural support was necessary in Hartofilakidis type 1, dysplasia cases. However, 27-30% of cases with type 2 or type 3 dysplasia required structural support. All cases with templated cup coverage of 65% or less required structural support. Templated coverage within 65-75% and over 75% resulted in 20% and 10% of patients receiving structural augmentation, respectively.
  
  
  CONCLUSIONS
  Preoperative planning for THA in the setting of hip dysplasia is crucial and can provide valuable insight to the need for column augmentation. However, the 3-D severity of the deformity may be underestimated in the 2-D radiographs.
authors: Orthopedic department, E. Wolfson medical center, Holon - Israel.|Sackler faculty of Medicine, Tel-Aviv University, Tel-Aviv - Israel.
authors: Dror
authors: D
authors: Lakstein
authors: Orthopedic Division, Mount Sinai Hospital, Toronto, Ontario - Canada.|Faculty of Medicine, University of Toronto, Toronto, Ontario - Canada.
authors: Zachary
authors: Z
authors: Tan
authors: Orthopedic department, E. Wolfson medical center, Holon - Israel.
authors: Nugzar
authors: N
authors: Oren
authors: Orthopedic Division, Mount Sinai Hospital, Toronto, Ontario - Canada.|Faculty of Medicine, University of Toronto, Toronto, Ontario - Canada.
authors: Tatu Johannes
authors: TJ
authors: Mäkinen
authors: Orthopedic Division, Mount Sinai Hospital, Toronto, Ontario - Canada.|Faculty of Medicine, University of Toronto, Toronto, Ontario - Canada.
authors: Allan E
authors: AE
authors: Gross
authors: Orthopedic Division, Mount Sinai Hospital, Toronto, Ontario - Canada.|Faculty of Medicine, University of Toronto, Toronto, Ontario - Canada.
authors: Oleg
authors: O
authors: Safir
mesh_terms: D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects / Q000379:methods*; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006618:Hip Dislocation, Congenital / Q000150:complications / Q000000981:diagnostic imaging* / Q000601:surgery; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015207:Osteoarthritis, Hip / Q000000981:diagnostic imaging* / Q000209:etiology / Q000601:surgery*; D010147:Pain Measurement; D011300:Preoperative Care / Q000379:methods; D011474:Prosthesis Design / Q000379:methods*; D020127:Recovery of Function; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed / Q000379:methods; D016896:Treatment Outcome