[Gonarthrosis in primary care: can analytical and radiological tests de done away with?].

OBJECTIVES: To evaluate if the rheumatologic clinical criteria established for the diagnosis of knee osteoarthritis are valid in primary care and if it is possible to do without the laboratory and radiologic criteria. DESIGN: Descriptive study of the agreement between the diagnosis exclusively clinical and the clinical, laboratory and radiologic diagnosis according the American Rheumatism Association (ARA) criteria. SETTING: Population of the health area of Talavera de la Reina (Toledo). PATIENTS: People with one or both knees non referred pain during the previous month, in spite of their characteristics, length or periodicity. MEASUREMENTS AND RESULTS: The ARA and R.D. Altman clinical diagnosis criteria of knee osteoarthritis were applied to the sample and they were compared with the diagnosis obtained with the clinical, laboratory and radiological criteria (reference diagnosis). The clinical diagnosis of knee osteoarthritis was established according the ARA criteria in 93% cases, according Altman in 86% and according the reference diagnosis in 87%. The sensibility and positive predictive value obtained using both clinical criteria are high, but the specificity is very low. CONCLUSIONS: The clinical criteria can be used in primary care, although they have a low specificity. It could be necessary to establish new criteria to ameliorate the specificity and the handling of these patients in primary care, to avoid unnecessary explorations.