The diagnosis of meniscus pathology.

A study of 281 patients evaluated for a meniscus pathologic condition was performed to assess the accuracy of the clinical diagnosis and arthrogram and delineate the role of arthroscopy. Following the clinical examination, the surgeon stated his level of confidence in his diagnosis, as did the radiologist in his interpretation of the arthrogram. In 134 cases inspected by arthroscopy or arthrotomy, the clinician proved to be correct 74% of the time, and the arthrogram accuracy in evaluating the medial meniscus was 89%; the majority of the errors were false positive diagnoses. In the 82 meniscus tears in which an arthrogram was performed the diagnosis was made in 80 cases, or 98%. The arthrogram accuracy in the lateral compartment was 81%; however, of the 31 lateral meniscus tears in which an arthrogram was performed, a positive diagnosis was yielded by arthrogram in only ten cases. In 34 lateral meniscus tears, a positive clinical diagnosis was made in only 12 cases. Arthroscopy was performed in 117 cases and proved helpful in patient management in 65 cases (55%). Arthroscopy was performed in 25 patients with lateral meniscus tears and a diagnosis of a lateral meniscus tear was made in all cases. The observations suggest that prior to performing an arthrotomy, arthroscopic examination of the knee should be performed routinely in patients suspected of having meniscus tears.