title: Diagnostic validity of alternative manual stress radiographic technique detecting subtalar instability with concomitant ankle instability.
abstract: OBJECTIVE
  To incorporate a diagnostic technique for measuring subtalar motion, namely "talar rotation", into the manual supination-anterior drawer stress radiographs for evaluation of the severity of rotational instability, and to determine its clinical relevance.
  
  
  METHODS
  Sixty-six patients with combined injuries of the anterior talofibular (ATFL) and calcaneofibular ligament (CFL) underwent three bilateral manual stress radiographs, and mean increments of anterior talar translation (mm), talar tilt (°), and talar rotation (%) in the injured ankle compared to the normal opposite side were measured with the technique. Intraobserver and interobserver reliability of each measure was assessed, and the difference in the degree of increments was compared according to the presence of additional cervical ligament insufficiency.
  
  
  RESULTS
  Ankle stress radiographic intraobserver and interobserver agreement was ICC = 0.91 and 0.82 for talar rotation (%), ICC = 0.64 and 0.51 for anterior talar translation, and ICC = 0.78 and 0.71 for talar tilt angle, respectively. In group 2 including patients with combined injuries of the ATFL and CFL along with additional cervical ligament insufficiency, a significantly higher increment of talar rotation, mean 6.4% (SD 3.4%), was observed compared to that of talar rotation, mean 4.1% (SD 2.7 ), in the other group (group 1) with an intact cervical ligament (p < 0.001).
  
  
  CONCLUSIONS
  A new comprehensive stress radiographic technique for diagnosis of chronic lateral ankle instability presented in this study might be a reliable and representable measurement tool to assess additional injury or instability of the subtalar joint.
  
  
  METHODS
  Prospective cohort study, Level II.
authors: Department of Orthopaedic Surgery, Kang-Dong Sacred Heart Hospital, Hallym University Medical Center, Gil-dong, Seoul, 134-701, Korea.
authors: Byung Hoon
authors: BH
authors: Lee
authors: Hallym Research Institute of Clinical Epidemiology, Hallym University, 1 Hallymdaehak-gil, Chuncheon, Gangwon-do, 200-702, Korea.
authors: Kyung-Hwa
authors: KH
authors: Choi
authors: Department of Orthopaedic Surgery, Kang-Dong Sacred Heart Hospital, Hallym University Medical Center, Gil-dong, Seoul, 134-701, Korea.
authors: Dong Yeon
authors: DY
authors: Seo
authors: Department of Orthopaedic Surgery, Kang-Dong Sacred Heart Hospital, Hallym University Medical Center, Gil-dong, Seoul, 134-701, Korea.
authors: Sang Min
authors: SM
authors: Choi
authors: Department of Orthopaedic Surgery, Kang-Dong Sacred Heart Hospital, Hallym University Medical Center, Gil-dong, Seoul, 134-701, Korea. kiga9@hanmail.net.
authors: Gab Lae
authors: GL
authors: Kim
mesh_terms: D000293:Adolescent; D000328:Adult; D016512:Ankle Injuries / Q000000981:diagnostic imaging* / Q000601:surgery; D000843:Ankle Joint / Q000000981:diagnostic imaging* / Q000601:surgery; D002908:Chronic Disease; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000000981:diagnostic imaging* / Q000601:surgery; D017844:Lateral Ligament, Ankle / Q000293:injuries / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011446:Prospective Studies; D011859:Radiography; D015203:Reproducibility of Results; D012399:Rotation; D013314:Stress, Mechanical; D013380:Subtalar Joint / Q000000981:diagnostic imaging* / Q000601:surgery; D055815:Young Adult
keywords: Ankle instability; Reliability; Stress radiography; Subtalar instability; Talar rotation