title: A prospective randomised study comparing TightRope and syndesmotic screw fixation for accuracy and maintenance of syndesmotic reduction assessed with bilateral computed tomography.
abstract: BACKGROUND
  The accuracy and maintenance of syndesmosis reduction are essential when treating ankle fractures with accompanying syndesmosis injuries. The primary aim of this study was to compare syndesmosis screw and TightRope fixation in terms of accuracy and maintenance of syndesmosis reduction using bilateral computed tomography (CT).
  
  
  METHODS
  Single centre, prospective randomised controlled clinical trial; Level of evidence 1.
  
  
  METHODS
  This study (ClinicalTrials.gov, NCT01742650) compared fixation with TightRope(®) (Arthrex, Naples, FL, USA) or with one 3.5-mm tricortical trans-syndesmotic screw in terms of accuracy and maintenance of syndesmosis reduction in Lauge-Hansen pronation external rotation, Weber C-type ankle fractures with associated syndesmosis injury. Twenty-one patients were randomised to TightRope fixation and 22 to syndesmotic screw fixation. Syndesmosis reduction was assessed using bilateral CT intraoperatively or postoperatively, and also at least 2 years after surgery. Functional outcomes and quality of life were assessed using the Olerud-Molander score, a 100-mm Visual Analogue Scale, the Foot and Ankle Outcome Score, and the RAND 36-Item Health Survey. Grade of osteoarthritis was qualified with follow-up cone-beam CT.
  
  
  RESULTS
  According to surgeons' assessment from intraoperative CT, screw fixation resulted in syndesmosis malreduction in one case whereas seven syndesmosis were considered malreduced when TightRope was used. However, open exploration and postoperative CT of these seven cases revealed that syndesmosis was well reduced if the ankle was supported at 90˚. Retrospective analysis of the intra- and post-operative CT by a radiologist showed that one patient in each group had incongruent syndesmosis. Follow-up CT identified three patients with malreduced syndesmosis in the syndesmotic screw fixation group, whereas malreduction was seen in one patient in the TightRope group (P = 0.33). Functional scores and the incidence of osteoarthritis showed no significant difference between groups.
  
  
  CONCLUSIONS
  Syndesmotic screw and TightRope had similar postoperative malreduction rates. However, intraoperative CT scanning of ankles with TightRope fixation was misleading due to dynamic nature of the fixation. After at least 2 years of follow-up, malreduction rates may slightly increase when using trans-syndesmotic screw fixation, but reduction was well maintained when fixed with TightRope. Neither the incidence of ankle joint osteoarthritis nor functional outcome significantly differed between the fixation methods.
authors.affiliation: Division of Orthopaedic and Trauma Surgery, Department Of Surgery, Oulu University Hospital, P.O. Box 21, FI 90029 OYS, Oulu, Finland. Electronic address: tero.kortekangas@ppshp.fi.
authors.forename: Tero
authors.initials: T
authors.lastname: Kortekangas
authors.affiliation: Omasairaala Oy, Finland.
authors.forename: Olli
authors.initials: O
authors.lastname: Savola
authors.affiliation: Division of Orthopaedic and Trauma Surgery, Department Of Surgery, Oulu University Hospital, P.O. Box 21, FI 90029 OYS, Oulu, Finland.
authors.forename: Tapio
authors.initials: T
authors.lastname: Flinkkilä
authors.affiliation: Department of Diagnostic Radiology, Oulu University Hospital, Finland.
authors.forename: Sannamari
authors.initials: S
authors.lastname: Lepojärvi
authors.affiliation: Division of Orthopaedic and Trauma Surgery, Department Of Surgery, Oulu University Hospital, P.O. Box 21, FI 90029 OYS, Oulu, Finland.
authors.forename: Simo
authors.initials: S
authors.lastname: Nortunen
authors.affiliation: Department of Surgery, Oulu University Hospital, Finland.
authors.forename: Pasi
authors.initials: P
authors.lastname: Ohtonen
authors.affiliation: Oulu University Hospital, Finland.
authors.forename: Jani
authors.initials: J
authors.lastname: Katisko
authors.affiliation: Division of Orthopaedic and Trauma Surgery, Department Of Surgery, Oulu University Hospital, P.O. Box 21, FI 90029 OYS, Oulu, Finland.
authors.forename: Harri
authors.initials: H
authors.lastname: Pakarinen
mesh_terms: D000328:Adult; D000368:Aged; D016512:Ankle Injuries / Q000000981:diagnostic imaging / Q000601:surgery*; D000843:Ankle Joint / Q000000981:diagnostic imaging / Q000601:surgery*; D001863:Bone Screws; D005260:Female; D005360:Fibula / Q000293:injuries*; D005387:Finland; D005593:Fracture Fixation, Internal; D006801:Humans; D007593:Joint Instability / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012399:Rotation; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
keywords: Ankle fractures; Bilateral computed tomography; Syndesmosis; Syndesmosis reduction; Syndesmotic screw; TightRope