This article describes a relatively common lesion of the lateral tibia
l plateau that has not been reported in the literature. This lesion is
a fissure of the articular cartilage parallel to the lateral meniscal
rim. Sometimes asymptomatic, this articular fissure was noted in 10 o
f 61 consecutive patients (16%) undergoing knee arthroscopy in an outp
atient surgery unit. This chondral fissure often demarcates an abrupt
transition between firm and healthy articular cartilage, which is cove
red by the lateral meniscus, and exposed articular cartilage, which is
soft and fibrillated. Progressive articular degeneration of knees wit
h this lesion has not been documented; therefore, the clinical signifi
cance of these chondral fissure is not yet known.