[Nuclear magnetic resonance and computerized tomography in meniscus injuries of the knee joint].

In a prospective study we evaluated the use of CAT scan and MRI in 53 patients with chronic symptoms and acute injuries of the knee joint. All these patients subsequently underwent surgery. A total of 21 patients had acute or chronic meniscus ruptures. The sensitivity of MRI was 86% (medial: 88%, lateral: 75%), its specificity, 95% (medial: 92%, lateral: 98%), its accuracy 93% (medial: 91%, lateral: 96%), its positive predictive value of 82% (medial: 83%, lateral: 75%), and its negative predictive value 96% (medial: 94%, lateral: 98%); CAT scan had a sensitivity of 86% (medial: 88%, lateral: 75%), a specificity of 97% (medial: 94%, lateral: 98%), an accuracy of 94% (medial: 93%, lateral: 96%), a positive predictive value of 86% (medial: 88%, lateral: 75%), and a negative predictive value of 97% (medial: 94%, lateral: 98%). In this study CAT scan and MRI proved to have a very high negative predictive value in the diagnostic of meniscal lesions. A negative result with one of these imaging techniques means that a rupture of a meniscus is highly unlikely. This may avoid unnecessary invasive procedures such as arthrotomies or arthroscopic examinations.