title: A 3-D CT Analysis of Screw and Suture-Button Fixation of the Syndesmosis.
abstract: BACKGROUND
  Historically, syndesmosis injuries have been repaired with screw fixation; however, some suggest that suture-button constructs may provide a more accurate anatomic and physiologic reduction. The purpose of this study was to compare changes in the volume of the syndesmotic space following screw or suture-button fixation using a preinjury and postoperative 3-D computed tomography (CT) model. The null hypothesis was that no difference would be observed among repair techniques.
  
  
  METHODS
  Twelve pairs of cadaveric specimens were dissected to identify the syndesmotic ligaments. Specimens were imaged with CT prior to the creation of a complete syndesmosis injury and were subsequently repaired using 1 of 3 randomly assigned techniques: (a) one 3.5-mm cortical screw, (b) 1 suture-button, and (c) 2 suture-buttons. Specimens were imaged postoperatively with CT. 3-D models of all scans and tibiofibular joint space volumes were calculated to assess restoration of the native syndesmosis. Analysis of variance and Tukey's method were used to compare least squares mean differences from the intact syndesmosis among repair techniques.
  
  
  RESULTS
  For each of the 3 fixation methods, the total postoperative syndesmosis volume was significantly decreased relative to the intact state. The total mean decreases in volume compared with the intact state for the 1-suture-button construct, 2-suture-button construct, and syndesmotic screw were -561 mm3(95% CI, -878 to -244), -964 mm3(95% CI, -1281 to -647) and -377 mm3(95% CI, -694 to -60), respectively.
  
  
  CONCLUSIONS
  All repairs notably reduced the volume of the syndesmosis beyond the intact state. Fixation with 1 suture-button was not significantly different from screw or 2-suture-button fixation; however, fixation with 2 suture-buttons resulted in significantly decreased volume compared with screw fixation.
  
  
  CONCLUSIONS
  The results of this study suggest that the 1-suture-button repair technique and the screw fixation repair technique were comparable for reduction of syndesmosis injuries, although both may overcompress the syndesmosis.
authors.affiliation: 1 Steadman Philippon Research Institute, Vail, CO, USA.
authors.forename: Jason M
authors.initials: JM
authors.lastname: Schon
authors.affiliation: 1 Steadman Philippon Research Institute, Vail, CO, USA.
authors.forename: Brady T
authors.initials: BT
authors.lastname: Williams
authors.affiliation: 1 Steadman Philippon Research Institute, Vail, CO, USA.
authors.forename: Melanie B
authors.initials: MB
authors.lastname: Venderley
authors.affiliation: 1 Steadman Philippon Research Institute, Vail, CO, USA.
authors.forename: Grant J
authors.initials: GJ
authors.lastname: Dornan
authors.affiliation: 1 Steadman Philippon Research Institute, Vail, CO, USA.|2 The Steadman Clinic, Vail, CO, USA.
authors.forename: Jonathon D
authors.initials: JD
authors.lastname: Backus
authors.affiliation: 1 Steadman Philippon Research Institute, Vail, CO, USA.
authors.forename: Travis Lee
authors.initials: TL
authors.lastname: Turnbull
authors.affiliation: 1 Steadman Philippon Research Institute, Vail, CO, USA.|2 The Steadman Clinic, Vail, CO, USA.
authors.forename: Robert F
authors.initials: RF
authors.lastname: LaPrade
authors.affiliation: 1 Steadman Philippon Research Institute, Vail, CO, USA.|2 The Steadman Clinic, Vail, CO, USA.
authors.forename: Thomas O
authors.initials: TO
authors.lastname: Clanton
mesh_terms: D000328:Adult; D016512:Ankle Injuries / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D000843:Ankle Joint / Q000033:anatomy & histology* / Q000601:surgery; D001863:Bone Screws; D002102:Cadaver; D005360:Fibula / Q000033:anatomy & histology / Q000601:surgery; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D019637:Orthopedic Procedures / Q000379:methods*; D053441:Suture Anchors; D013977:Tibia / Q000033:anatomy & histology / Q000601:surgery; D014057:Tomography, X-Ray Computed
keywords: TightRope; ankle; biomechanical; cadaveric; flexible implant; instability; screw; surgical technique; suture-button; syndesmosis; tibiofibular