[Evaluation of knee radiograms as criterion of femoro-tibial gonarthrosis development].

Within the context of the initiation of practising rheumatologists to the methodology and management of clinical trials, it seemed opportune to carry out a clinical research study whose aim would be pedagogical as well as scientific: pedagogical by making them aware of the problems linked with the management of a clinical trial and the problem of the variability of the measurements; scientific by trying to appreciate the clinical significance of the radiological examination data in the course of femoro-tibial gonarthrosis. The patients suffering from femoro-tibial gonarthrosis corresponding to the ARA criteria and having given their consent have been included in a multicentric prospective study where each investigator had to record--apart from the patient inclusion criteria--his personal characteristics, the characteristics of the arthrositic disease (site, aetiology, history, clinical condition). Moreover, the radiological analysis of a recent, frontal photograph of the knee on charge has been carried out by a practising rheumatologist and by a university-hospital rheumatologist. The number of observations collected (879), the low percentage of non exploitable data (3.4%) are in favour of having clinical research studies carried out by practising rheumatologists. The analysis of the study shows the following: 1) the inter-observer variability of the reading of the photograph of the gonarthrosis is high outside three parameters (osteophyte, degree of pinch and height of the spacing measured in millimetres) with an interclass correlation coefficient of 0.69, 0.71 and 0.69 respectively; 2) the radiographical examination data correlate only very partially with the clinical elements of the disease.