title: Percutaneous screw fixation of acetabular fractures with 2D fluoroscopy-based computerized navigation.
abstract: BACKGROUND
  The treatment of displaced acetabular fractures with formal open reduction and internal fixation has gained general acceptance. However, extensile exposure can lead to complications. Two-dimensional fluoroscopy-based computerized navigation for placement of percutaneous screw across non-displaced acetabular fractures has attracted interest by making use of stored patient-specific imaging data to provide real-time guidance in multiple image planes during implant placement. The purpose of the present study was to document early treatment results and complications associated with this new technique and evaluate its clinical application to displaced acetabular fractures amenable to closed or limited open reduction.
  
  
  METHODS
  Eighteen adult patients with 12 non-displaced and 8 displaced acetabular fractures were treated with percutaneous screw fixation under the guidance of a fluoroscopy-based navigation system. There were 14 men and four women with a mean age of 42.1 years (range 19-54 years). According to the AO and Orthopaedic Trauma Association Classification, there were nine 62-A3, five 62-B1, three 62-B2, and three 62-B3. The mean follow-up was 21 months (range 12-28 months). The mean time from injury to surgery was 4 days (range 2-7 days).
  
  
  RESULTS
  A total of 30 acetabular screws were inserted, including 21 anterior column screws and 9 posterior column screws. The average operation time was 24.6 min (range 16-47 min) from the image acquisition to wound closure. The average fluoroscopic time was 28.4 s (range 11-58 s). Compared to the final position of the screw, the average deviated distance of wire tip was 2.5 mm (range 1.1-3.6 mm) and the average trajectory difference was 2.45 degrees (range 1.5 degrees -4.6 degrees ). Maximal gap displacement averaged 10 mm (range 2-22 mm) preoperatively and 3 mm (range 0-5 mm) postoperatively; while maximal step displacement averaged 4 mm (range 1-10 mm) preoperatively and 2 mm (range 0-4 mm) postoperatively. One patient sustained a transient femoral nerve palsy and resolved 2 months after the operation. No superficial or deep infection occurred. Using the rating system of D'Aubigne and Postel, 13 patients had excellent results, 4 patients had good results, and 1 patient had a fair result.
  
  
  CONCLUSIONS
  Percutaneous screw fixation of acetabular fractures with 2D fluoroscopy-based navigation could be applied not only to non-displaced fractures but also to displaced fractures amenable to closed or limited open reduction.
authors.affiliation: Department of Orthopaedic Surgery, Shanghai Sixth People's Hospital, Jiaotong University, 600 Yishan Road, Shanghai, People's Republic of China. honggao630@yahoo.com.cn
authors.forename: Gao
authors.initials: G
authors.lastname: Hong
authors.forename: Luo
authors.initials: L
authors.lastname: Cong-Feng
authors.forename: Hu
authors.initials: H
authors.lastname: Cheng-Fang
authors.forename: Zhang
authors.initials: Z
authors.lastname: Chang-Qing
authors.forename: Zeng
authors.initials: Z
authors.lastname: Bing-Fang
mesh_terms: D000077:Acetabulum / Q000000981:diagnostic imaging / Q000293:injuries* / Q000601:surgery; D000328:Adult; D001863:Bone Screws; D015331:Cohort Studies; D005260:Female; D005471:Fluoroscopy; D005500:Follow-Up Studies; D005593:Fracture Fixation, Internal / Q000295:instrumentation / Q000379:methods*; D017102:Fracture Healing / Q000502:physiology; D050723:Fractures, Bone / Q000000981:diagnostic imaging* / Q000601:surgery*; D006801:Humans; D004204:Joint Dislocations / Q000000981:diagnostic imaging / Q000601:surgery; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000295:instrumentation / Q000379:methods; D015641:Radiography, Interventional; D018570:Risk Assessment; D025321:Surgery, Computer-Assisted / Q000379:methods*; D016896:Treatment Outcome; D055815:Young Adult