title: Inter and intra-observer reliability in assessment of the position of the lateral sesamoid in determining the severity of hallux valgus.
abstract: BACKGROUND
  The position of the lateral sesamoid on standard dorso-plantar weight bearing radiographs, with respect to the lateral cortex of the first metatarsal, has been shown to correlate well with the degree of the hallux valgus angle. This study aimed to assess the inter- and intra-observer error of this new classification system.
  
  
  METHODS
  Five orthopaedic consultants and five trainee orthopaedic surgeons were recruited to assess and document the degree of displacement of the lateral sesamoid on 144 weight-bearing dorso-plantar radiographs on two separate occasions. The severity of hallux valgus was defined as normal (0%), mild (≤50%), moderate (51-≤99%) or severe (≥100%) depending on the percentage displacement of the lateral sesamoid body from the lateral cortical border of the first metatarsal.
  
  
  RESULTS
  Consultant intra-observer variability showed good agreement between repeated assessment of the radiographs (mean Kappa=0.75). Intra-observer variability for trainee orthopaedic surgeons also showed good agreement with a mean Kappa=0.73. Intraclass correlations for consultants and trainee surgeons was also high.
  
  
  CONCLUSIONS
  The new classification system of assessing the severity of hallux valgus shows high inter- and intra-observer variability with good agreement and reproducibility between surgeons of consultant and trainee grades.
authors.affiliation: Rochdale Infirmary, Whitehall Street, Rochdale OL12 0NB, Lancashire, United Kingdom. Electronic address: sunilpanchani@doctors.org.uk.
authors.forename: Sunil
authors.initials: S
authors.lastname: Panchani
authors.affiliation: Rochdale Infirmary, Whitehall Street, Rochdale OL12 0NB, Lancashire, United Kingdom. Electronic address: jonathan_reading@hotmail.com.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Reading
authors.affiliation: Rochdale Infirmary, Whitehall Street, Rochdale OL12 0NB, Lancashire, United Kingdom. Electronic address: jaymehta19@yahoo.co.uk.
authors.forename: Jaysheel
authors.initials: J
authors.lastname: Mehta
mesh_terms: D006215:Hallux Valgus / Q000000981:diagnostic imaging*; D006801:Humans; D015588:Observer Variation; D015203:Reproducibility of Results; D012716:Sesamoid Bones / Q000000981:diagnostic imaging*; D012720:Severity of Illness Index
keywords: Classification; Foot surgery; Hallux valgus; Sesamoid