Observation of anomalous insertion of the medial meniscus on the anterior cruciate ligament

Meniscus tear developed by pulling of the anomalous insertion of medial meniscus on anterior cruciate ligament

“…Rainio et al reported 11 cases of AIMM among 987 consecutive arthroscopies. The reported incidence of AIMM was 1.2% [13]. Cha et al reviewed the arthroscopic examination data from 1,326 patients with knee injuries and/or pain.…”

“…They reported the incidence of AIMM onto the ACL to be 2.3% (30/1,326 cases) [3]. Medial meniscus abnormalities are an uncommon finding during the arthroscopic examination [13]. During human fetal development at 10–11-week gestation, the internal femoromeniscal and meniscotibial joints are organized.…”

“…It is rare, however, to find an abnormality of the medial meniscus [6, 10, 13]. For that reason, arthroscopic surgeons normally do not pay close attention to such abnormalities.…”

“…For that reason, arthroscopic surgeons normally do not pay close attention to such abnormalities. One of the rare variants of the medial meniscus is the anomalous insertion of medial meniscus (AIMM) onto the anterior cruciate ligament (ACL) [3, 6, 13]. Cases of AIMM evaluated by arthroscopic examination or by MRI have been reported, but there is no English literature to our knowledge regarding a medial meniscal tear arising from an AIMM on the ACL.…”

Ressonância magnética na avaliação das variações anatômicas meniscais e da anatomia ligamentar perimeniscal: potenciais causas de erro de interpretação

“…The anomalous insertion of the anterior horn of the medial meniscus into the anterior cruciate ligament is an infrequent variation, with a variable incidence reported in literature (never > 2.2% (16,21) . At MRI, such abnormality is seen as a bandshaped structure with low signal intensity, extending from the anterior horn of the medial meniscus to the anterior cruciate ligament, in an almost parallel pathway, with a variable thickness, sometimes too thin to be individualized at MRI.…”