title: Effect of computerized tomography on classification and treatment plan for patellar fractures.
abstract: OBJECTIVE
  To evaluate the impact of computerized tomography (CT) scan on both fracture classification and surgical planning of patellar fractures.
  
  
  METHODS
  Prospective study.
  
  
  METHODS
  Academic level I trauma center.
  
  
  METHODS
  Four fellowship-trained orthopaedic trauma surgeons analyzed radiographs of 41 patellar fractures. Each fracture was classified (OTA/AO classification), and a treatment plan was developed using plain radiographs alone. The process was repeated (4-6 weeks later) with addition of CT scan. After 12 months, the 2-step analysis was repeated and interobserver reliability and intraobserver reproducibility were assessed.
  
  
  RESULTS
  Suboptimal intra- and interobserver reliability was found for the surgical plan and classification using the OTA/AO system, despite the addition of a CT scan. After addition of CT, reviewers modified the classification in 66% of cases and treatment plan in 49%. CT frequently demonstrated a distinctive and severely comminuted distal pole fracture; this fracture pattern was present in 88% of cases and was unappreciated on plain radiographs in 44% of those cases. This pattern is unaccounted for by the present OTA/AO classification.
  
  
  CONCLUSIONS
  CT facilitates improved delineation of patellar fracture patterns. Understanding the distal pole fracture pattern is fundamental in choosing a fixation construct. A fracture-specific classification system, based on CT scans, should be developed.
authors.affiliation: Orthopedic Trauma Service, Hospital for Special Surgery, New York Presbyterian Hospital, Weill Medical College of Cornell University, New York, NY 10021, USA. lionellazaro@gmail.com
authors.forename: Lionel E
authors.initials: LE
authors.lastname: Lazaro
authors.forename: David S
authors.initials: DS
authors.lastname: Wellman
authors.forename: Nadine C
authors.initials: NC
authors.lastname: Pardee
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Gardner
authors.forename: Jose B
authors.initials: JB
authors.lastname: Toro
authors.forename: Neil R
authors.initials: NR
authors.lastname: Macintyre
authors.forename: David L
authors.initials: DL
authors.lastname: Helfet
authors.forename: Dean G
authors.initials: DG
authors.lastname: Lorich
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005593:Fracture Fixation, Internal / Q000379:methods*; D050723:Fractures, Bone / Q000000981:diagnostic imaging* / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010329:Patella / Q000000981:diagnostic imaging* / Q000293:injuries*; D010347:Patient Care Planning; D018579:Patient Selection; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome