title: Effect of syndesmosis injury in SER IV (Weber B)-type ankle fractures on function and incidence of osteoarthritis.
abstract: BACKGROUND
  Syndesmosis fixation of Lauge-Hansen SER IV, Weber B ankle fractures is controversial. This study compared a matched pair of SER IV patients with stress proven syndesmotic injuries with the same number without stress proven syndesmotic injury in terms of functional, pain, and radiologic result.
  
  
  METHODS
  The study was based on a RCT-study comparing syndesmotic transfixation to no fixation in SER IV (Weber B)-type ankle fractures. Twenty-four patients with a syndesmosis injury found on the intraoperative 7.5 Nm standardized external rotation test were compared to 24 patients with a stable syndesmosis. The pairs were matched by fracture morphology, sex, and age. The primary outcome measure was ankle function as assessed by the Olerud-Molander score. Weight-bearing plain radiographs and 3T MRI of the injured ankle were used to assess ankle joint congruity and osteoarthritis, according to Kellgren-Lawrence classification and cartilage defects.
  
  
  RESULTS
  The Olerud-Molander score was 86 in syndesmosis injury patients and 90 in patients with normal syndesmosis (P = .28). The incidence of ankle joint osteoarthritis on plain radiographs was not significantly different between the groups (Grade I 5% vs 21%; Grade II 86% vs 75%; Grade III 9% vs 4%; P = .34). MRI scans showed TC joint cartilage defects in 54% of the patients: 12 (56%) in the syndesmosis injury group vs 13 (54%) in the group without syndesmosis injury (P > .9).
  
  
  CONCLUSIONS
  After 4 to 6 years of follow-up, clinical and radiologic outcome were not different in patients with syndesmosis injury compared to patients with stable syndesmosis in SER IV (Weber B)-type ankle fractures.
  
  
  METHODS
  Prognostic Level II, comparative study.
authors.affiliation: Division of Orthopedic and Trauma Surgery, Department of Surgery, Oulu University Hospital, Oulu, Finland tero.kortekangas@ppshp.fi.
authors.forename: Tero
authors.initials: T
authors.lastname: Kortekangas
authors.affiliation: Division of Orthopedic and Trauma Surgery, Department of Surgery, Oulu University Hospital, Oulu, Finland.
authors.forename: Tapio
authors.initials: T
authors.lastname: Flinkkilä
authors.affiliation: Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland.
authors.forename: Jaakko
authors.initials: J
authors.lastname: Niinimäki
authors.affiliation: Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland.
authors.forename: Sannamari
authors.initials: S
authors.lastname: Lepojärvi
authors.affiliation: Department of Surgery, Oulu University Hospital, Oulu, Finland.
authors.forename: Pasi
authors.initials: P
authors.lastname: Ohtonen
authors.affiliation: Omasairaala, Helsinki, Finland.
authors.forename: Olli
authors.initials: O
authors.lastname: Savola
authors.affiliation: Division of Orthopedic and Trauma Surgery, Department of Surgery, Oulu University Hospital, Oulu, Finland.
authors.forename: Harri
authors.initials: H
authors.lastname: Pakarinen
mesh_terms: D000328:Adult; D064386:Ankle Fractures / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery; D016512:Ankle Injuries / Q000145:classification / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005260:Female; D005593:Fracture Fixation, Internal; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000503:physiopathology*; D010147:Pain Measurement; D011859:Radiography; D013484:Supination / Q000502:physiology; D016474:Weight-Bearing
keywords: Weber B; ankle fracture; stress test; supination-eversion; syndesmosis