MAGNETIC-RESONANCE-IMAGING, SCINTIGRAPHY, AND ARTHROSCOPIC EVALUATIONOF TRAUMATIC HEMARTHROSIS OF THE KNEE

Forty patients with traumatic knee hemarthrosis were examined within 1 week after injury and observations made with magnetic resonance imagi ng, scintigraphy, arthroscopic evaluation, radiography, and physical e xamination were compared. Thirty-four patients (85%) had anterior cruc iate ligament injuries according to the arthroscopic findings and 28 ( 83%) of these had associated meniscal tears, Magnetic resonance imagin g confirmed the arthroscopic findings, especially if only meniscal tea rs that required surgery were taken into account (sensitivity, 94% for the lateral and 83% for the medial meniscus), However, the specificit y of magnetic resonance imaging was only 29% and 27% for the lateral a nd medial menisci, respectively, and the accuracy was 28% and 50%, res pectively. Marrow edemas, or bone bruises, were seen on magnetic reson ance imaging in 80% of the patients and were mainly seen in the latera l compartment. Bone scans correlated well with magnetic resonance imag ing findings of marrow edemas. Plain radiographs were normal in all bu t one case. We show that magnetic resonance imaging does not add infor mation on the status of the anterior cruciate ligament compared with t he clinical examination, and that it may be as good as arthroscopic ev aluation for the diagnosis of meniscal tears that require surgery.