title: Arthroscopic and magnetic resonance image appearance and reconstruction of the anterior talofibular ligament in cases of apparent functional ankle instability.
abstract: BACKGROUND
  Many patients report feeling functional ankle instability, despite having no clinically demonstrable lateral instability.
  
  
  OBJECTIVE
  Some patients who experience functional instability of the ankle have substantial abnormalities of the anterior talofibular ligament despite having apparently normal lateral laxity in clinical examination.
  
  
  METHODS
  Case series; Level of evidence, 4.
  
  
  METHODS
  Fourteen patients who had functional ankle instability after sprain, despite having no clinically demonstrable lateral instability, were included in this study. All subjects underwent standard stress radiography, magnetic resonance imaging, and ankle arthroscopy. These patients were treated with anatomical reconstruction of the anterior talofibular ligament.
  
  
  RESULTS
  Arthroscopic assessment revealed 3 cases with no ligamentous structure with scar tissue, 9 cases with partial ligament tears and scar tissue on the disrupted anterior talofibular ligament fiber, and 2 cases of abnormal course of the ligament at the fibular or talar attachment. Magnetic resonance imaging revealed the following: 5 cases of discontinuity of the anterior talofibular ligament, 2 cases of narrowing of the anterior talofibular ligament, 4 cases of high-intensity lesion in the anterior talofibular ligament, and 3 normal cases. The mean American Orthopaedic Foot and Ankle Society Ankle Hindfoot scale score was 66.2 +/- 3.2 points at preoperation and 92.3 +/- 4.4 points 2 years after surgery.
  
  
  CONCLUSIONS
  All patients in this study with functional ankle instability, despite their having no demonstrable abnormal lateral laxity, had morphologic ligamentous abnormality on arthroscopic assessment.
authors.affiliation: Department of Orthopaedic Surgery, Teikyo University School of Medicine, 2-11-1, Kaga, Itabashi, Tokyo, Japan. mtakao@med.teikyo-u.ac.jp
authors.forename: Masato
authors.initials: M
authors.lastname: Takao
authors.forename: Ken
authors.initials: K
authors.lastname: Innami
authors.forename: Takashi
authors.initials: T
authors.lastname: Matsushita
authors.forename: Yuji
authors.initials: Y
authors.lastname: Uchio
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Ochi
mesh_terms: D000293:Adolescent; D000328:Adult; D000843:Ankle Joint / Q000503:physiopathology / Q000601:surgery*; D001182:Arthroscopy; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000601:surgery*; D017844:Lateral Ligament, Ankle; D008279:Magnetic Resonance Imaging; D008297:Male; D019637:Orthopedic Procedures; D013628:Talus / Q000293:injuries