title: Ankle fractures have features of an osteoporotic fracture.
abstract: We report the bone attenuation of ankle joint measured on computed tomography (CT) and the cause of injury in patients with ankle fractures. The results showed age- and gender-dependent low bone attenuation and low-energy trauma in elderly females, which suggest the osteoporotic features of ankle fractures.
  
  
  BACKGROUND
  This study was performed to investigate the osteoporotic features of ankle fracture in terms of bone attenuation and cause of injury.
  
  
  METHODS
  One hundred ninety-four patients (mean age 51.0 years, standard deviation 15.8 years; 98 males and 96 females) with ankle fracture were included. All patients underwent CT examination, and causes of injury (high/low-energy trauma) were recorded. Mean bone attenuations of the talus, medial malleolus, lateral malleolus, and distal tibial metaphysis were measured on CT images. Patients were divided into younger age (<50 years) and older age (≥50 years) groups, and mean bone attenuation and causes of injury were compared between the two groups in each gender.
  
  
  RESULTS
  Proportion of low-energy trauma was higher in the older age group than in the younger age group, but the difference was only significant in female gender (p = 0.011). The older age group showed significantly lower bone attenuation in the talus, medial malleolus, lateral malleolus, and distal tibial metaphysis than the younger age group in both genders. The older age group showed more complex pattern of fractures than the younger age group. With increasing age, bone attenuations tended to decrease and the difference of bone attenuation between the genders tended to increase in the talus, medial malleolus, lateral malleolus, and distal tibial metaphysis.
  
  
  CONCLUSIONS
  Ankle fracture had features of osteoporotic fracture that is characterized by age- and gender-dependent low bone attenuation. Ankle fracture should not be excluded from the clinical and research interest as well as from the benefit of osteoporosis management.
authors.affiliation: Department of Orthopaedic Surgery, Seoul National University Bundang Hospital, 300 Gumi-Dong, Bundang-Gu, Seongnam, Gyeonggi, 463-707, South Korea.
authors.forename: K M
authors.initials: KM
authors.lastname: Lee
authors.forename: C Y
authors.initials: CY
authors.lastname: Chung
authors.forename: S S
authors.initials: SS
authors.lastname: Kwon
authors.forename: S H
authors.initials: SH
authors.lastname: Won
authors.forename: S Y
authors.initials: SY
authors.lastname: Lee
authors.forename: M K
authors.initials: MK
authors.lastname: Chung
authors.forename: M S
authors.initials: MS
authors.lastname: Park
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D064386:Ankle Fractures; D000843:Ankle Joint / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D058866:Osteoporotic Fractures / Q000000981:diagnostic imaging* / Q000209:etiology; D015203:Reproducibility of Results; D012737:Sex Factors; D013628:Talus / Q000000981:diagnostic imaging; D013977:Tibia / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed / Q000379:methods; D055815:Young Adult