title: The impact of different types of talus deformation after treatment of clubfeet.
abstract: Deformation of the talus in idiopathic congenital clubfeet is a known problem after treatment. However evidence on types of talus deformation and clinical relevance is rare. The aims of this study were first to define different types of talus deformation, and second, to evaluate the impact of these types on long-term results.
  
  
  
  At a minimum follow-up of ten years 40 idiopathic clubfeet treated by a modified dorsomedial release were analyzed. Based on morphological appearance and the widened range of radius to length ratios (R/L-ratio) in treated clubfeet deformed tali were divided into two groups: tali with decreased R/L-ratios were classified as small-dome talus deformation (SD), tali with increased R/L-ratios were classified as flat-top talus deformation (FT). The impact on degree of arthrosis in the ankle joint, clinical outcome, and ankle range of motion was analyzed.
  
  
  
  Small-dome talus deformation (SD) was found in nine feet. This group showed decreased R/L-ratios and increased talus opening angles, which were linked to an increased range of motion of the ankle joint (p = 0.033). The impact on onset of arthrosis was not significant for this group (p = 0.056). The group of flat top talus deformation (nine feet) showed increased R/L-ratios and decreased talus opening angles, decreased range of motion (p = 0.019), and a significant impact on onset of arthrosis (p = 0.010).
  
  
  
  Our study defines a new subgroup of talus deformation: the small dome talus deformation tends to show a better ankle joint range of motion and a lower risk of arthrosis compared to the classical flat dome talus deformation.
authors.affiliation: Department of Orthopaedics, Medical University of Vienna, Waehringer Gürtel 18-20, 1090, Vienna, Austria. alexander.kolb@meduniwien.ac.at.
authors.forename: Alexander
authors.identifier: 0000-0001-7869-2586
authors.initials: A
authors.lastname: Kolb
authors.affiliation: Department of Orthopaedics, Medical University of Vienna, Waehringer Gürtel 18-20, 1090, Vienna, Austria.
authors.forename: Madeleine
authors.initials: M
authors.lastname: Willegger
authors.affiliation: Department of Orthopaedics, Medical University of Vienna, Waehringer Gürtel 18-20, 1090, Vienna, Austria.
authors.forename: Reinhard
authors.initials: R
authors.lastname: Schuh
authors.affiliation: Center for Medical Statistics, Informatics and Intelligent Systems, Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Kaider
authors.affiliation: Department of Orthopaedics, Medical University of Vienna, Waehringer Gürtel 18-20, 1090, Vienna, Austria.
authors.forename: Catharina
authors.initials: C
authors.lastname: Chiari
authors.affiliation: Department of Orthopaedics, Medical University of Vienna, Waehringer Gürtel 18-20, 1090, Vienna, Austria.
authors.forename: Reinhard
authors.initials: R
authors.lastname: Windhager
mesh_terms: D000843:Ankle Joint / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D003025:Clubfoot / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D008297:Male; D019637:Orthopedic Procedures / Q000009:adverse effects* / Q000379:methods; D016059:Range of Motion, Articular; D012189:Retrospective Studies; D013628:Talus / Q000473:pathology / Q000601:surgery*
keywords: Clubfoot treatment; Radiological analysis; Talus dome deformation