title: Calcaneal varus angle change in normal calcaneus: a three-dimensional finite element analysis.
abstract: The objective of the study was to investigate the stress changes in the posterior articular surface of the calcaneus following alternation of the calcaneal varus angle in normal calcaneus and discuss the clinical significance of the calcaneal varus angle. Axial view radiographs of 165 volunteers were obtained to measure the calcaneal varus angle of normal calcaneus. A calcaneal model with different varus angle changes (including +2°, +4°, +6°, -2°, -4°, and -6°) was established using Creo 2.0 software. Stress changes at different calcaneal varus angles in the posterior articular surface of the calcaneus under a load of 100 N were measured. Stressed areas in posterior articular facets were slightly fewer following +2°, +4°, and +6° changes in varus angle than in normal varus angles with stress concentering regions moving to the anteromedial aspect of the posterior calcaneal facet. However, stress concentering areas in posterior calcaneal facets following -4° and -6° changes in varus angle obviously moved to the anterior and posterior medial side of posterior calcaneal facets. Stress distribution in the posterior articular surface of the calcaneus varies with the calcaneal varus angle. The decrease in calcaneal varus angle following operative treatment of calcaneal fractures should be controlled within 2°.
authors.affiliation: Trauma Center Emergency Department, The Third Hospital of Hebei Medical University, 139 Ziqiang Road, Shijiazhuang, 050051, People's Republic of China.
authors.forename: Xue-Bin
authors.initials: XB
authors.lastname: Zhang
authors.affiliation: Shijiazhuang Vocational Technology Institute, Shijiazhuang, 050081, People's Republic of China.
authors.forename: Hao
authors.initials: H
authors.lastname: Wu
authors.affiliation: Qinglong Manchu Autonomous County Hospital of Hebei Province, Qinglong, 066500, Hebei, People's Republic of China.
authors.forename: Li-Guo
authors.initials: LG
authors.lastname: Zhang
authors.affiliation: Trauma Center Emergency Department, The Third Hospital of Hebei Medical University, 139 Ziqiang Road, Shijiazhuang, 050051, People's Republic of China.
authors.forename: Ji-Tang
authors.initials: JT
authors.lastname: Zhao
authors.affiliation: Trauma Center Emergency Department, The Third Hospital of Hebei Medical University, 139 Ziqiang Road, Shijiazhuang, 050051, People's Republic of China. zhangyingze88@163.com.
authors.forename: Ying-Ze
authors.initials: YZ
authors.lastname: Zhang
mesh_terms: D000293:Adolescent; D000328:Adult; D001696:Biomechanical Phenomena; D002111:Calcaneus / Q000502:physiology*; D005260:Female; D020342:Finite Element Analysis; D005528:Foot / Q000502:physiology; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D013314:Stress, Mechanical; D055815:Young Adult
keywords: Axial radiograph; Calcaneus; Finite element analysis; Varus angle