title: Establishing an optimal trajectory for calcaneotibial K-wire fixation in emergent treatment of unstable ankle fractures.
abstract: OBJECTIVE
  In unstable ankle fractures the associated soft tissue damage can be a therapeutic challenge. The aim of this study was to optimize planning of minimally invasive stabilization of ankle fractures by calcaneotibial transfixation, which is a demanding technique due to the complex hind foot anatomy.
  
  
  METHODS
  In a retrospective radiographic analysis the angles and dimensions of a safe drill tunnel for calcaneotibial K-wire insertion were defined on standard radiographs of the ankle joint. 165 lateral weight-bearing radiographs (77 right; 88 left) and 147 (80 right; 67 left) mortise views of 186 (90 right; 96 left) uninjured feet from 123 patients (74 women (114 feet); 49 men (72 feet)) were included in this study. The average patient age was 49 (range, 13-85) years. Inter- and intra-observer reliability was evaluated on 20 randomized radiographs that were analyzed in a default set, three times, by two different examiners on three different days.
  
  
  RESULTS
  In the lateral view the drilling tunnel was orientated at 59.4° to the plantar plane with a maximum proximal variance of 7.1 image-mm. Distal variance cannot be tolerated since an ankle joint injury would ensue. In the mortise view the drill tunnel was directed with a mean angle of 18.4° to the distal tibial articular surface. At most a mean of 11° fibular- and 13.4° tibial- expansion can be tolerated. Intra- and inter-observer reliability was higher for the angles than for the drill corridors.
  
  
  CONCLUSIONS
  The three-dimensional (3D) orientation for safe K-wire placement for calcaneotibial transfixation should adhere to the drill tunnels established in this study.
authors.affiliation: Unfallchirurgische Klinik, Medizinische Hochschule Hannover, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Schröder
authors.affiliation: Unfallchirurgische Klinik, Medizinische Hochschule Hannover, Germany.
authors.forename: V
authors.initials: V
authors.lastname: Stüber
authors.affiliation: Unfallchirurgische Klinik, Medizinische Hochschule Hannover, Germany.
authors.forename: E
authors.initials: E
authors.lastname: Walendzik
authors.affiliation: Cappagh National Orthopaedic Hospital, Finglas, Dublin, Ireland.
authors.forename: P F
authors.initials: PF
authors.lastname: O'Loughlin
authors.affiliation: Institut für Biostatistik, Medizinische Hochschule Hannover, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Zapf
authors.affiliation: Unfallchirurgische Klinik, Medizinische Hochschule Hannover, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Krettek
authors.affiliation: Unfallchirurgische Klinik, Medizinische Hochschule Hannover, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Gaulke
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D064386:Ankle Fractures / Q000601:surgery*; D001864:Bone Wires; D002111:Calcaneus / Q000601:surgery*; D005260:Female; D005593:Fracture Fixation, Internal / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D012189:Retrospective Studies; D013977:Tibia / Q000601:surgery*; D016896:Treatment Outcome; D016474:Weight-Bearing; D055815:Young Adult
keywords: Hind foot anatomy; ankle fracture; calcaneotibial transfixation; hind foot radiographs