title: Anatomical study for an update comprehension of clubfoot. Part I: Bones and joints.
abstract: OBJECTIVE
  The aim of our study was to elucidate the gross anatomical changes of bones and joints in idiopathic clubfeet.
  
  
  METHODS
  Gross dissection was carried out on seven idiopathic clubfeet of fetuses aborted between the 25th and 37th week of gestation and compared to two normal feet (27th and 36th week of gestation). Particular attention was paid to the articular surfaces, shapes and angles of all bones and their skeletal relationships.
  
  
  RESULTS
  The talar neck-trochlea angle in clubfeet ranged from 37 degrees to 41 degrees , in normal feet from 27 degrees to 33 degrees . In clubfeet the deviation of the neck of the talus relative to the body was between 28 degrees and 43 degrees , in normal feet between 22 degrees and 24 degrees . The posterior joint surface was in an anterolateral position and even flat transversely. The head of the clubfeet tali was turned along a longitudinal axis in the opposite direction compared to the normal ones. Instead of a typically saddle-shaped posterior talar surface of the calcaneus, it was triangular and flat transversely, and a bony stability in the subtalar joint was not achieved. The angle of torsion of the calcaneus showed no significant difference between normal and clubfeet. The anterior surface was flat, medially twisted and orientated upwards.
  
  
  CONCLUSIONS
  We presume that the calcaneus is the primary fault, which might be explained by pathologic biomechanical forces during development.
authors.affiliation: Institute of Anatomy, Medical University Graz, Harrachgasse 21, 8010, Graz, Austria, gunther.windisch@meduni-graz.at.
authors.forename: Gunther
authors.initials: G
authors.lastname: Windisch
authors.forename: Friedrich
authors.initials: F
authors.lastname: Anderhuber
authors.forename: Verena
authors.initials: V
authors.lastname: Haldi-Brändle
authors.forename: Gerhard Ulrich
authors.initials: GU
authors.lastname: Exner