title: The fate of Böhler's angle in conservatively-treated displaced intra-articular calcaneal fractures.
abstract: OBJECTIVE
  Although the predictive value of Böhler's angle on outcome remains subject of debate, the initial angle at the time of trauma still guides treatment. Changes in Böhler's angle during follow-up are frequently reported following surgical treatment of displaced intra-articular calcaneal fractures (DIACF). The aim of the present study was to determine the changes in Böhler's angle as a measure of secondary fracture displacement following conservative management of DIACF.
  
  
  METHODS
  Thirty-eight patients with a total of 44 displaced intra-articular calcaneal fractures treated conservatively with a minimum of two lateral radiographs during follow-up were analysed. Böhler's angle at different follow-up times was measured by three observers. The change in angle was compared with the angle at trauma, and influence of trauma mechanism and common calcaneal fracture classifications were determined.
  
  
  RESULTS
  The results showed a significant decline over time of the Böhler's angle in conservatively-treated patients of more than 11° on average at a mean follow-up of 29.2 weeks. This decrease was not related to gender, the initial angle, or the Essex-Lopresti or Sanders classification. A statistically significantly higher decrease was detected in high energetic trauma compared with low energetic trauma.
  
  
  CONCLUSIONS
  The conservative treatment of displaced intra-articular calcaneal fractures is still a viable option, yet a significant secondary displacement in time should be taken into account, as reflected in a decrease of Böhler's angle of 11° up to one year following trauma.
authors.affiliation: Department of Surgery-Traumatology, Erasmus MC, University Medical Center Rotterdam, Room H822-k, P.O. Box 2040, 3000, CA, Rotterdam, The Netherlands.
authors.forename: Berdine
authors.initials: B
authors.lastname: Bakker
authors.forename: Jens A
authors.initials: JA
authors.lastname: Halm
authors.forename: Esther M M
authors.initials: EM
authors.lastname: Van Lieshout
authors.forename: Tim
authors.initials: T
authors.lastname: Schepers
mesh_terms: D000328:Adult; D002111:Calcaneus / Q000000981:diagnostic imaging* / Q000293:injuries*; D002370:Casts, Surgical; D005260:Female; D005500:Follow-Up Studies; D050723:Fractures, Bone / Q000000981:diagnostic imaging / Q000628:therapy*; D006801:Humans; D057072:Intra-Articular Fractures / Q000000981:diagnostic imaging / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D011859:Radiography; D016059:Range of Motion, Articular / Q000502:physiology; D012189:Retrospective Studies; D013640:Tarsal Joints / Q000000981:diagnostic imaging / Q000502:physiology; D016896:Treatment Outcome; D014947:Wounds and Injuries