title: Lateral Tibiocalcaneal Angle As a Determinant for Percutaneous Achilles Tenotomy for Idiopathic Clubfeet.
abstract: BACKGROUND
  The aim of the present study was to evaluate the clinical value of using the lateral tibiocalcaneal (LTiC) angle, measured on a lateral radiograph made with the foot and ankle in maximal dorsiflexion, instead of the ankle dorsiflexion (ADF) angle, measured on physical examination, as a determining indicator of the need for percutaneous Achilles tenotomy after Ponseti serial cast treatment of idiopathic clubfoot.
  
  
  METHODS
  We identified patients with idiopathic clubfoot who had been treated at our institution between March 2006 and June 2012. After exclusion of patients with Diméglio grade-I clubfoot and those followed for less than two years, 125 idiopathic clubfeet were evaluated. The clubfeet were grouped according to their LTiC and ADF angles, after which we evaluated the clinical outcomes of each group and investigated the prognostic effects of each angle-based decision regarding whether to perform percutaneous Achilles tenotomy.
  
  
  RESULTS
  Patients with a favorable LTiC angle (≤80°) showed no sagittal relapse even though none underwent percutaneous Achilles tenotomy. In contrast, patients with an unfavorable LTiC angle (>80°) had a high chance of sagittal relapse if percutaneous Achilles tenotomy had not been performed, even when they had a favorable ADF angle (≥15°). The LTiC-angle-based decision showed the most significant prognostic value in multivariate analyses of relapse-free and surgery-free survival rates.
  
  
  CONCLUSIONS
  The LTiC angle measured on simple radiographs is a more objective and prognostic indicator of the need for percutaneous Achilles tenotomy, as compared with the ADF angle measured on physical examination, in patients with idiopathic clubfoot.
  
  
  METHODS
  Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.
authors.affiliation: Department of Orthopedic Surgery, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, 88, Olympic-ro, 43-gil, Songpa-gu, Seoul 138-736, South Korea. E-mail address for S. Kang: ziozio79@daum.net. E-mail address for S.-S. Park: sspark@amc.seoul.kr.
authors.forename: Seungcheol
authors.initials: S
authors.lastname: Kang
authors.affiliation: Department of Orthopedic Surgery, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, 88, Olympic-ro, 43-gil, Songpa-gu, Seoul 138-736, South Korea. E-mail address for S. Kang: ziozio79@daum.net. E-mail address for S.-S. Park: sspark@amc.seoul.kr.
authors.forename: Soo-Sung
authors.initials: SS
authors.lastname: Park
mesh_terms: D000125:Achilles Tendon / Q000601:surgery*; D000704:Analysis of Variance; D002111:Calcaneus / Q000000981:diagnostic imaging; D002370:Casts, Surgical; D002675:Child, Preschool; D003025:Clubfoot / Q000000981:diagnostic imaging* / Q000601:surgery*; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D008297:Male; D016016:Proportional Hazards Models; D011859:Radiography; D016059:Range of Motion, Articular / Q000502:physiology*; D020127:Recovery of Function; D012008:Recurrence; D012189:Retrospective Studies; D018570:Risk Assessment; D058971:Tenotomy / Q000009:adverse effects / Q000379:methods*; D013977:Tibia / Q000000981:diagnostic imaging; D016896:Treatment Outcome