title: The "communication line" suggests occult posterior malleolar fracture associated with a spiral tibial shaft fracture.
abstract: OBJECTIVE
  To demonstrate radiographical characteristics of the relationship between distal spiral tibial shaft fractures and associated occult posterior malleolar fractures (PMF) that confirmed by CT and MRI.
  
  
  METHODS
  X-rays for a ninety-six patients with spiral tibia fracture and associated PMF were reviewed. All patients additionally had an ankle CT. Patients with a negative CT scans underwent an ankle MRI. Radiographic observations included fracture location, characteristics, and a presence of a fracture line between the two injuries.
  
  
  RESULTS
  The spiral tibia fracture line was contiguous with PMF in 89 of 96 cases after evaluation with the CT and MRI. The line connecting the two injuries, which occurs between the medial inferior apex of the spiral tibia fracture line and the posterior superior apex of the PMF was identified as the "communication line". In 47 of the 89 conjunction fractures, the "communication line" was detectable preoperatively and in 12 cases postoperatively by anteroposterior radiograph. By using the CT and MRI scans, we found that no "communication line" was present in only 7 cases.
  
  
  CONCLUSIONS
  It is important to understand the nature of the association between distal spiral tibial shaft fractures and occult posterior malleolar fractures for optimal stabilization of the fracture and for appropriate rehabilitation. The "communication line" is a useful diagnostic clue for early recognition the occult PMF and alerts a closer evaluation of the lateral view and further CT examination.
authors.affiliation: Department of Orthopaedic Surgery, Third Hospital of Hebei Medical University, 139 Ziqiang Road, Shijiazhuang, China. hzy707@yahoo.com.cn
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Hou
authors.forename: Liping
authors.initials: L
authors.lastname: Zhang
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhang
authors.forename: Shuangquan
authors.initials: S
authors.lastname: Yao
authors.forename: Jinshe
authors.initials: J
authors.lastname: Pan
authors.forename: Kaan
authors.initials: K
authors.lastname: Irgit
authors.forename: Yingze
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000293:Adolescent; D000328:Adult; D016512:Ankle Injuries / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000209:etiology / Q000601:surgery; D005260:Female; D005593:Fracture Fixation, Internal / Q000379:methods; D005596:Fractures, Closed / Q000175:diagnosis* / Q000000981:diagnostic imaging; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013978:Tibial Fractures / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000209:etiology / Q000601:surgery; D014057:Tomography, X-Ray Computed