Discoid lateral menisci in older patients. A radiographic study of 21 cases.

Twenty-three knees of 21 patients over 40 years of age with discoid lateral menisci were examined by radiography. The mean age of the patients was 59.7 years (range: 40-78 years). No patient had symptoms before the age of 40 and only 12 knees gave symptoms from the lateral compartment, although tears of a discoid lateral meniscus were diagnosed by arthrography in 21 of the 23 knees. Varus inclination occurred more frequently than valgus inclination. Subchondral bone sclerosis was more common in the medial compartment. However, high incidences of marginal osteophytes in the lateral compartment and morphological anomalies (cupping or flattening) of the lateral tibial plateau were revealed by radiography.