Meniscal pathology. The expanding role of magnetic resonance imaging.

Magnetic resonance imaging (MRI) is a recently developed diagnostic medical imaging technology that shows great promise in the evaluation of knee meniscal diseases. Fifty-seven patient knees were evaluated by a single experienced MRI interpreter; the findings were compared with arthroscopic findings by a single experienced knee arthroscopist. The overall sensitivity and specificity rates of MRI for tears in virgin menisci compared to arthroscopy were both 92%. These results support reports in the literature that MRI is an accurate noninvasive technique for evaluating meniscal tears. Seven patients were treated with arthroscopic meniscal repair and were evaluated by MRI before and after surgery. Despite an asymptomatic postoperative status in six patients, abnormal intrameniscal signal persisted in four. An unstable meniscal fragment was visualized in the patient with postoperative pain. MRI is also useful in evaluating meniscal degeneration, meniscal ossicles, parameniscal cysts, and abnormal meniscal morphology. MRI is the noninvasive diagnostic technique of choice in evaluating a spectrum of knee meniscal diseases.