A comparison of magnetic resonance imaging and arthroscopic evaluation of chondral lesions of the knee.

This study compared the sensitivity of magnetic resonance imaging (MRI) to arthroscopy in detecting localized chondral lesions of the knee, especially lesion depth, in 28 patients with 32 femoral and tibial lesions. Average patient age was 24.3 years. Chondral lesions were classified according to five grades. The sensitivity of MRI was 100% for grade 3 (deep) and higher lesions, but was less for superficial chondral lesions. Arthroscopic and MRI grades coincided for only three lesions. Magnetic resonance imaging was not so accurate regarding depth even for deep chondral lesions, although subchondral lesions undetectable by arthroscopy often were detected by MRI.