As far as the Weber classification was concerned, the observers were asked to classify the radiographs into four categories: A, B, C and ‘non-classifiable’. Four observers reviewed 94 sets of radiographs at an interval of three months. Thomsen et al 9 assessed multiobserver agreement of the Weber 11 and Lauge-Hansen 12 classifications based on frontal, lateral and oblique views. After an interval of four weeks, the observers were again requested to classify the same set of radiographs, which had been mixed in order to minimise any chance of recollection. To minimise bias they did not take part in the process of classification. The first author (IAM) and a co-author (AMM) recorded the responses from the observers. The observers were asked to classify the fractures according to the Weber classification. Two were consultants (including NHH) and three were orthopaedic registrars (including BM) in their second, fourth and sixth years of training. The selected radiographs were blinded and then reviewed by five different observers with different levels of clinical experience. Patients who had special radiographs such as stress views or further imaging such as CT scans were also excluded. The first author (IAM) reviewed the radiographs, and those which did not show a definite fibular fracture were excluded. Using the hospital coding system, 50 patients with ankle fractures were randomly selected. We have assessed the inter- and intra-observer agreement for the Weber classification using standard anteroposterior and lateral radiographs of the ankle rather than the frontal, lateral and oblique views as mentioned in the study of Thomsen et al. However, several studies have shown that the use of the kappa coefficient value alone is not sufficient to assess agreement between multiple observers. Thomsen et al 9 showed that there was an acceptable inter-and intra-observer agreement of both the Weber and the Lauge-Hansen 12 classification systems using the kappa coefficient. Weber 11 classified fractures of the ankle into categories A (fracture of the fibula is distal to the syndesmosis), B (fracture is at the level of the syndesmosis) and C (fracture is proximal to the syndesmosis). 1, 3, 8, 9 Since Cohen 10 established the kappa co-efficient in 1960, it has been widely used to assess the level of agreement between observers. Several authors have attempted to evaluate the reliability and reproducibility of these classification systems, 1 – 8 some of which have better reproducibility and reliability than others. They give clarity to communication and facilitate comparison of published results. Classification systems for fractures are often based on the mechanism of injury and are used to devise a plan of management or to predict prognosis.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |