title: Changes in the syndesmotic reduction after syndesmotic screw fixation for ankle malleolar fractures: One-year longitudinal evaluations using computer tomography.
abstract: BACKGROUND
  To evaluate time-dependent changes in the syndesmotic reduction after syndesmotic screw fixation and one year after screw removal for ankle malleolar fractures, and to assess whether the incidence of syndesmotic malreduction changes depending on the measurement method.
  
  
  METHODS
  We assessed twenty patients who underwent syndesmotic screw fixation for ankle fractures. The syndesmotic screws were removed after six weeks of the fracture surgery. Syndesmotic reduction was assessed within two weeks of the fracture surgery and one year after the screw removal using the axial computer tomographic images. Side-to-side differences in the anterior and posterior tibiofibular distances, anteroposterior fibular translation, and fibular rotation were measured.
  
  
  RESULTS
  The mean anterior tibiofibular distance was 0.7mm after syndesmotic fixation. It increased to 1.9mm at one year after screw removal (p=0.002). After syndesmotic fixation, four ankles had malreduction of the anterior tibiofibular distance, including three ankles with widening and one with overtightening. At one year, eight ankles had malreduction, all of whom had widening. The other measurement values did not change over time (0.1mm vs. 0.6mm for the posterior tibiofibular distance, 0.2mm vs. 0.3mm for the anteroposterior fibular translation, and 0.7° vs. 0° for the fibular rotation). The incidences of malreduction were significantly different depending on the definition of malreduction, ranging from 10% to 50% after syndesmotic fixation (p=0.01) and from 20% to 60% at one year after screw removal (p=0.02).
  
  
  CONCLUSIONS
  The anterior tibiofibular distance widened after one year of syndesmotic screw removal. The incidence of malreduction varied depending on the measurement method.
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan. Electronic address: orthopaedics@hotmail.co.jp.
authors.forename: Jun
authors.initials: J
authors.lastname: Endo
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan. Electronic address: y-satoshi@mvb.biglobe.ne.jp.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yamaguchi
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan. Electronic address: masahi1214@hotmail.com.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Saito
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan. Electronic address: morimori@dk9.so-net.ne.jp.
authors.forename: Tsuguo
authors.initials: T
authors.lastname: Morikawa
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan. Electronic address: ryu-a@nona.dti.ne.jp.
authors.forename: Ryuichiro
authors.initials: R
authors.lastname: Akagi
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan. Electronic address: sasho1234@yahoo.co.jp.
authors.forename: Takahisa
authors.initials: T
authors.lastname: Sasho
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D064386:Ankle Fractures / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D016512:Ankle Injuries / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D000843:Ankle Joint / Q000000981:diagnostic imaging* / Q000503:physiopathology; D001863:Bone Screws; D020878:Device Removal; D005260:Female; D005593:Fracture Fixation, Internal / Q000379:methods*; D006801:Humans; D007593:Joint Instability / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D055815:Young Adult
keywords: Ankle malleolar fracture; Computer tomography; Syndesmotic reduction; Syndesmotic screw fixation