DIFFERENTIAL-DIAGNOSIS OF VERTEBRAL OSTEO POROSIS - RELIABILITY OF RADIOLOGICAL CLASSIFICATION CRITERIA

Background: Radiologically identified vertebral deformities, e. g. wed ge-, fish-, or crush-vertebrae are not always a consequence of local o steoporosis. Other frequent pathomechanisms include Morbus Scheuermann , degenerative changes, overt trauma, and congenital dysplasia. This r equires differential diagnosis of vertebral deformities. Radiological classification criteria have to satisfy various methodological require ments to ensure reliability of the results. Methods: Inter-rater relia bility of more than 30 radiological findings was assessed in 4 German centres of the European Vertebral Osteoporosis Study (EVOS). One hundr ed randomly selected EVOS cases from the West-Berlin population, each contributing 2 lateral X-rays from the thoracic and lumbar spine respe ctively, were independently evaluated by 7 observers. All observers we re medical doctors, 4 of them heads or members of clinical radiologica l departments. Thus each observer read 200 radiographs. Radiological a lterations in the form and structure of 13 vertebrale which were consi dered to be relevant for the differential diagnosis of osteoporosis we re recorded in a standardized documentation form. Additionally global judgements (e. g. ''osteoporotic spine'' yes/no) were required. To qua ntify agreement Fleiss' kappa (kappa) for nominal data and multiple ob servers was used.