Objective: To evaluate the diagnostic value of ultrasonography in meniscal tears that were diagnosed by magnetic resonance imaging (MRI).
Design: Twenty-seven knees with meniscal tears and 14 knees without tears on MRI were prospectively evaluated. A radiologist performed the ultrasonography and evaluated the presence and locations of the meniscal tears. MRI was used as the reference standard.
Results: Twenty-nine menisci with tears and 53 menisci without tears were identified by MRI. Twenty-two tears were in the medial menisci, and seven tears were in the lateral menisci. In the 29 meniscal tears, the ultrasonographic diagnosis was correct in 25 (86.2%) and incorrect in 4 (13.8%) menisci. In the 53 menisci without tears, the ultrasonographic diagnosis was correct in 45 (84.9%) and incorrect in 8 (15.1%) menisci. Ultrasonography showed a sensitivity, specificity, accuracy, and positive and negative predictive values for meniscal tears of 86.2%, 84.9%, 85.4%, 75.8%, and 91.8%, respectively. Of the four intracapsular injuries observed by MRI in injured knees, an osteochondritis dessecans was only observed by ultrasonography.
Conclusions: Ultrasonography is an accurate imaging study for diagnosing meniscal tears. The results correlated with those obtained by MRI; this suggests that ultrasonography can be a useful imaging modality in uninjured knees.