MAGNETIC-RESONANCE-IMAGING (MRI) AND ARTHROSCOPY IN THE DETECTION OF MENISCAL DEGENERATIONS - CORRELATION OF ARTHROSCOPY AND MRI WITH HISTOLOGY FINDINGS

In a prospective double-blind study, the capability of magnetic resona nce imaging (MRI) and arthroscopy in the detection and grading of meni scal degenerations is evaluated by correlating MRI findings and arthro scopic diagnoses with a histologic grading model. In 82.8% of our resu lts, grading based on MRI studies corresponded with the histologic gra ding classification. In 12 instances a meniscal degeneration verified at light microscopy was not detected at MRI, whereas in 15 cases tomog raphy yielded a false-positive result. The overall accuracy was calcul ated to be 0.93 with a specificity of 0.79 and a sensitivity of 0.96. Concerning the evaluation of meniscal degenerations, MRI provides a po sitive predictive value of 0.95 and a negative predictive value of 0.8 2. Compared with the diagnostic specificity of the anterior and poster ior zones, that of the intermediate segment of the meniscus is signifi cantly reduced (p < 0.001). At arthroscopy, meniscal degenerations wer e diagnosed with an overall accuracy of 38.8%, a sensitivity of 27.5%, and a specificity of 75.5%. In 80 cases of grade 3 abnormalities, fiv e false-negative diagnoses were made initially. These results suggest that MRI offers a valuable diagnostic potential providing reliable inf ormation about the internal consistency of the meniscus complementary to diagnostic arthroscopy.