title: Epidemiology and imaging appearance of the normal Bi-/multipartite hallux sesamoid bone.
abstract: BACKGROUND
  Turf toe is a hyperextension injury of the hallux metatarsophalangeal joint that can be difficult to diagnose on physical examination and imaging. Diastasis of the bi- or multipartite sesamoid of the hallux has been implicated as 1 potential radiographic finding of turf toe injury, and when present may require operative management. However, the normal interval for the bi-/multipartite sesamoid has not yet been established.
  
  
  METHODS
  A total of 671 foot radiograph series were reviewed in effort to quantify the dominant interval of the bi-/multipartite sesamoid bone with respect to potential influencing factors including right versus left foot, medial and/or lateral sesamoid involvement, patient age and gender, and weight versus non-weight-bearing radiograph technique.
  
  
  RESULTS
  The prevalence of a bi-/multipartite hallux sesamoid was 14.3% in our population. The dominant sesamoid interval ranged from 0-2 mm, with an average of 0.79 mm.
  
  
  CONCLUSIONS
  We conclude that sesamoid diastasis should be considered, in the appropriate clinical setting, when the sesamoid interval is greater than 2 mm on a routine AP radiograph of the foot.
  
  
  METHODS
  Level III, comparative study.
authors.affiliation: University of Washington, Seattle, WA, USA.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Favinger
authors.affiliation: University of Washington, Seattle, WA, USA jporrino@uw.edu.
authors.forename: Jack Anthony
authors.initials: JA
authors.lastname: Porrino
authors.affiliation: University of Washington, Seattle, WA, USA.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Richardson
authors.affiliation: University of Washington, Seattle, WA, USA.
authors.forename: Hyojeong
authors.initials: H
authors.lastname: Mulcahy
authors.affiliation: University of Washington, Seattle, WA, USA.
authors.forename: Felix S
authors.initials: FS
authors.lastname: Chew
authors.affiliation: University of Washington, Seattle, WA, USA.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Brage
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001265:Athletic Injuries / Q000000981:diagnostic imaging / Q000453:epidemiology; D005260:Female; D006215:Hallux Valgus / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008683:Metatarsophalangeal Joint / Q000000981:diagnostic imaging / Q000293:injuries*; D008875:Middle Aged; D011859:Radiography; D016059:Range of Motion, Articular; D012716:Sesamoid Bones / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D016474:Weight-Bearing; D055815:Young Adult
keywords: forefoot disorders; hallux disorders; sports; statistical analysis; trauma