Traumatic knee injuries: the accuracy of MRI compared with arthroscopy

Forty-three knees in 43 patients were evaluated preoperatively with magnetic resonance imaging (MRI). Both menisci and cruciate ligaments subsequently were examined directly with arthroscopy. A grading scale was used to evaluate intrameniscal signal intensity and to predict the presence of meniscal tear using MR. Compared with arthroscopy, the sensitivity, specificity and accuracy of MRI were, respectively, 100%, 88% and 93% for tears of the medial meniscus; 72.7%, 93.7% and 88.4% for tears of the lateral meniscus; 100%, 96.7% and 97.7% for tears of the anterior cruciate ligament. There were no posterior cruciate ligament tears, and none were suggested from the images. Our results show that MRI is a valuable diagnostic aid in the management of traumatic knee injury.