Right knee, view from the anterolateral portal, female, 15 years of age. Incomplete discoid medial meniscus presenting coalescence of the meniscus with the insertion of the anterior cruciate ligament (ACL). Discoid medial meniscus has a very low estimated incidence of 0.06% to 0.3%(1-3), with fewer than 100 cases described to date(2). Discoid medial meniscus is complete in about 50% of the cases and incomplete in the other 50%(2,3), and is more common in men than in women(2,3), with clinical presentation typically in the second and third decades of life(2,3). Only two other cases of discoid medial meniscus presenting coalescence with the ACL have been described in the literature(4,5).