title: The Eftekhar and Kerboul classifications in assessment of developmental dysplasia of the hip in adult patients. Measurement of inter- and intraobserver reliability.
abstract: OBJECTIVE
  To measure the inter- and intraobserver reliability of two radiologic classification systems in the evaluation of severity of osteoarthritis secondary to developmental dysplasia of the hip in adult patients and to compare these systems to historically published data on two more commonly used classification systems described by Crowe and by Hartofikakidis.
  
  
  METHODS
  Eighty-six dysplastic hips on 66 anteroposterior standard pelvic x-rays were rated according to the criteria of Eftekhar and Kerboul by three observers with different levels of clinical training. To assess intraobserver reliability, the measurement was repeated 3 months later. Statistical analysis was performed by calculating the weighted kappa correlation coefficient and the overall kappa coefficient.
  
  
  RESULTS
  Both classification systems showed a sufficient interobsever reliability, reaching a kappa coefficient of 0.73 for the system according to Eftekhar and 0.716 for the Kerboul classification system. Intraobserver reliability revealed a kappa coefficient of 0.778 for the Eftekhar system and 0.697 for the classification according to Kerboul.
  
  
  CONCLUSIONS
  Both systems showed good inter- and intraobserver reliability for use in daily practice. However, they did not reach the known reliability of the grading systems published by Crowe and by Hartofikakidis. Because these systems are more frequently used, we would recommend one of them to grade the severity of osteoarthritis secondary to developmental dysplasia of the hip in adult patients instead of the ones described by Eftekhar or by Kerboul.
authors.affiliation: Department of Orthopaedics, University of Ulm, Oberer Eselsberg 45, Ulm 89081, Germany. a-r.brunner@web.de
authors.forename: Alexander
authors.initials: A
authors.lastname: Brunner
authors.forename: Benjamin
authors.initials: B
authors.lastname: Ulmar
authors.forename: Heiko
authors.initials: H
authors.lastname: Reichel
authors.forename: Ralf
authors.initials: R
authors.lastname: Decking