THE PREVALENCE OF ABNORMAL MAGNETIC-RESONANCE-IMAGING FINDINGS IN ASYMPTOMATIC KNEES - WITH CORRELATION OF MAGNETIC-RESONANCE-IMAGING TO ARTHROSCOPIC FINDINGS IN SYMPTOMATIC KNEES

The purpose of this study was to prospectively evaluate the prevalence of abnormal magnetic resonance imaging scans of the knees of asymptom atic subjects. A prospective analysis of magnetic resonance imaging to arthroscopic findings in symptomatic knees was also performed. The pr evalence of meniscal tears found in asymptomatic knees was 5.6% (media l meniscus, 1.9%; lateral meniscus, 3.7%). Other abnormal findings inc luded a prevalence of 1.9% for degenerative changes of the medial femo ral condyle and 3.7% both for ganglion cysts and patellofemoral joint articular cartilage degenerative changes. There was also a prevalence of 24.1% of Grade II signal changes of the posterior horn of the media l meniscus. Statistical comparison of our results to previous studies revealed that the magnetic resonance imaging scan readings on the asym ptomatic knees in this study were accurate and lesions were correctly identified. We recommend that clinicians match clinical signs and symp toms with magnetic resonance imaging findings before instituting surgi cal treatment because of a 5.6% prevalence of meniscal tears in the as ymptomatic population. The significance of the high percentage of post erior horn medial meniscal Grade II signal changes is unknown.